agar and Disease-Models--Animal

Helicobacter pylori (H. pylori) is an obligate microaerobion and does not survive in low oxygen. Sodium sulfite (SS) reacts and consume oxygen in solutions. The present study aimed to investigate the effects of SS on H. pylori. The effects of SS on oxygen concentrations in solutions and on H. pylori in vivo and in vitro were examined, and the mechanisms involved were explored. The results showed that SS decreased the oxygen concentration in water and artificial gastric juice. In Columbia blood agar and special peptone broth, SS concentration-dependently inhibited the proliferation of H. pylori ATCC43504 and Sydney strain-1 in Columbia blood agar or special peptone broth, and dose-dependently decreased the number of H. pylori in Mongolian gerbils and Kunming mouse infection models. The H. pylori was relapsed in 2 weeks withdrawal and the recurrence in the SS group was lower than that in the positive triple drug group. These effects were superior to positive triple drugs. After SS treatments, the cell membrane and cytoplasm structure of H. pylori were disrupted. SS-induced oxygen-free environment initially blocked aerobic respiration, triggered oxidative stress, disturbed energy production. In conclusion, SS consumes oxygen and creates an oxygen-free environment in which H. pylori does not survive. The present study provides a new strategy and perspective for the clinical treatment of H. pylori infectious disease.

Topics: Agar; Animals; Disease Models, Animal; Gastric Mucosa; Gerbillinae; Helicobacter Infections; Helicobacter pylori; Mice; Peptones

Uropathogenic Escherichia coli (UPEC) is the primary cause of urinary tract infections (UTIs) in animals and humans. We applied Transposon-Directed Insertion Site sequencing (TraDIS) to determine the fitness genes in two well-characterized UPEC strains, UTI89 and CFT073, in order to identify fitness factors during UTI in a pig model. This novel animal model better reflects the course of UTI in humans than the commonly used mouse model, and facilitates the differentiation between sessile and planktonic UPEC populations. A total of 854 and 483 genes in UTI89 and CFT073, respectively, were predicted to contribute to growth in pig urine, and 1257 and 764, were scored as required for colonization of the bladder. The combined list of fitness genes for growth in urine and cystitis contained 741 (UTI89) and 439 (CFT073) genes. The essential genes for growth on LB agar media supplemented with kanamycin and the fitness factors during growth in human urine were also analyzed in CFT073. A total of 457 essential genes were identified and the pool of fitness genes for growth in human urine included 215 genes. The gene rfaG, which is involved in lipopolysaccharide biosynthesis, was included in all the fitness-gene-lists and was further confirmed to be relevant for all the conditions tested regardless of the host and the strain. Thus, this gene may represent a promising target for the development of new therapeutic strategies against UTI UPEC-associated. Besides this important observation, the study revealed strain-specific differences in gene-essentiality as well as in the fitness-gene-repertoire for growth in human urine and UTI of the pig model, and it identified novel factors required for UPEC-induced UTIs.

Topics: Agar; Animals; Disease Models, Animal; Escherichia coli Infections; Escherichia coli Proteins; Humans; Kanamycin; Lipopolysaccharides; Mice; Swine; Urinary Tract Infections; Uropathogenic Escherichia coli

Animal models of chronic lung infection with P. aeruginosa (PA) are useful tools to improve antibiotic (ATB) treatment. Two main models based on the pulmonary instillation of PA embedded in agar or calcium-alginate beads are currently used. However, these two polymers used to prepare the beads have different properties; for example, agar is a neutral polysaccharide while alginate is anionic. We hypothesized that the effect of an ATB on PA entrapped in agar or calcium-alginate beads depends on its physicochemical properties, including charge, and concentration. To test this hypothesis, PAs were entrapped in agar or calcium-alginate beads dispersed in a growth medium containing either tobramycin (TOB), selected as a cationic ATB, or ciprofloxacin (CIP) selected as a neutral zwitterionic ATB. In vitro, time-kill curves evaluating the efficacy of ATBs over time were performed by measuring the light emitted by a bioluminescent PA for 42 h in the presence of ATB concentrations ranging from 0 to 100 times the MIC. In the presence of CIP, time-kill curves obtained with PA trapped in agar or calcium-alginate beads were comparable, whatever the CIP concentration used. In the presence of TOB, a clear difference was observed between the kill curves obtained with PA embedded in agar or calcium-alginate beads. While PA trapped within agar displayed the same susceptibility than the planktonic one, it was unresponsive to TOB for concentrations up to 1-fold MIC when trapped in calcium-alginate. At 10-fold the TOB's MIC, the luminescence emitted by PA01 in the agar beads was reduced by 95% after 40 h, whereas it returned to the same initial value for PA01 trapped in alginate-based beads. The reduction in TOB efficiency was even greater when alginate-based beads were dispersed in a mucus-simulating medium. These results show that the agar and alginate beads models can be interchangeable only for uncharged ATB, such as CIP, but not for cationic ATB, like TOB. In vitro experiments performed in this study could be a quick way to evaluate the effect of each model on a given ATB before performing animal experiments.

Topics: Agar; Alginates; Animals; Anti-Bacterial Agents; Ciprofloxacin; Disease Models, Animal; Lung; Pseudomonas aeruginosa; Pseudomonas Infections; Respiratory Tract Infections; Tobramycin

Many topical commercial products are currently available for the treatment of onychomycosis. However, limited data are available concerning their antifungal activity. Using an in vitro onychomycosis model, the daily application of seven nail formulations was compared to the antifungal reference drug amorolfine (Loceryl(®) ) and evaluated for inhibitory activity against Trichophyton mentagrophytes using an agar diffusion test. Of all commercial nail formulations, only Excilor(®) and Nailner(®) demonstrated inhibitory activity, which was much lower compared to the daily application of Loceryl(®) . However, Excilor(®) showed similar efficacy compared to the conventional weekly application of Loceryl(®) . These results suggest a role for organic acids in the antifungal effect of Excilor(®) (acetic acid, ethyl lactate) and Nailner(®) (lactic acid, citric acid, ethyl lactate) as all tested formulations without organic acids were inactive.

Topics: Administration, Topical; Agar; Animals; Antifungal Agents; Cattle; Cosmetics; Disease Models, Animal; Hoof and Claw; Immunodiffusion; Morpholines; Onychomycosis; Trichophyton

Triazole prophylaxis has become the norm in patients with hematological malignancies. Breakthrough infections caused by Mucorales during triazole prophylaxis remain a challenging problem. We found that preexposure of Rhizopus oryzae to antifungal triazoles (fluconazole, voriconazole, posaconazole, and itraconazole) did not modify the in vitro susceptibility of Rhizopus oryzae to posaconazole. In contrast, preexposure of Rhizopus to triazoles was associated with the enhanced in vitro susceptibility of R. oryzae to amphotericin B. Preexposure to posaconazole did not alter the virulence of R. oryzae in the fly model of mucormycosis.

Topics: Agar; Animals; Antifungal Agents; Culture Media; Disease Models, Animal; Drosophila melanogaster; Female; Fluconazole; Itraconazole; Microbial Sensitivity Tests; Mucormycosis; Rhizopus; Survival Analysis; Triazoles; Virulence; Voriconazole

Murine models of acute and chronic lung infection have been used in studying Pseudomonas aeruginosa for assessing in vivo behavior and for monitoring of the host response. These models provide an important resource for studies of the initiation and maintenance of bacterial infection, identify bacterial genes essential for in vivo maintenance and for the development and testing of new therapies. The rat has been used extensively as a model of chronic lung infection, whereas the mouse has been a model of acute and chronic infection. Intratracheal administration of planktonic bacterial cells in the mouse provides a model of acute pneumonia. Bacteria enmeshed in agar beads can be used in the rat and mouse to reproduce the lung pathology of cystic fibrosis patients with advanced chronic pulmonary disease. Here, we describe the methods to assess virulence of P. aeruginosa using prototype and clinical strains in the Sprague-Dawley rat and the C57BL/6NCrlBR mouse by monitoring several measurable read-outs including weight loss, mortality, in vivo growth curves, the competitive index of infectivity, and the inflammatory response.

Topics: Acute Disease; Agar; Animals; Biological Assay; Chronic Disease; Colony Count, Microbial; Disease Models, Animal; Host-Pathogen Interactions; Inflammation; Kinetics; Lung; Male; Mice, Inbred C57BL; Pseudomonas aeruginosa; Pseudomonas Infections; Rats, Sprague-Dawley; Respiratory Tract Infections; Survival Analysis; Virulence

Pseudomonas aeruginosa is an opportunistic pathogen that can adapt to changing environments and can secrete an exopolysaccharide known as alginate as a protection response, resulting in a colony morphology and phenotype referred to as mucoid. However, how P. aeruginosa senses its environment and activates alginate overproduction is not fully understood. Previously, we showed that Pseudomonas isolation agar supplemented with ammonium metavanadate (PIAAMV) induces P. aeruginosa to overproduce alginate. Vanadate is a phosphate mimic and causes protein misfolding by disruption of disulfide bonds. Here we used PIAAMV to characterize the pathways involved in inducible alginate production and tested the global effects of P. aeruginosa growth on PIAAMV by a mutant library screen, by transcriptomics, and in a murine acute virulence model. The PA14 nonredundant mutant library was screened on PIAAMV to identify new genes that are required for the inducible alginate stress response. A functionally diverse set of genes encoding products involved in cell envelope biogenesis, peptidoglycan remodeling, uptake of phosphate and iron, phenazine biosynthesis, and other processes were identified as positive regulators of the mucoid phenotype on PIAAMV. Transcriptome analysis of P. aeruginosa cultures growing in the presence of vanadate showed differential expression of genes involved in virulence, envelope biogenesis, and cell stress pathways. In this study, it was observed that growth on PIAAMV attenuates P. aeruginosa in a mouse pneumonia model. Induction of alginate overproduction occurs as a stress response to protect P. aeruginosa, but it may be possible to modulate and inhibit these pathways based on the new genes identified in this study.

Topics: Acute Disease; Agar; Alginates; Animals; Bacterial Proteins; Culture Media; Disease Models, Animal; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Glucuronic Acid; Heat-Shock Response; Hexuronic Acids; Humans; Mice; Molecular Sequence Data; Oligonucleotide Array Sequence Analysis; Pneumonia, Bacterial; Pseudomonas aeruginosa; Pseudomonas Infections; Vanadates; Virulence

Candida albicans, a dimorphic fungus, undergoes hyphal development in response to many different environmental cues, including growth in contact with a semi-solid matrix. C. albicans forms hyphae that invade agar when cells are embedded in or grown on the surface of agar, and the integral membrane protein Dfi1p is required for this activity. In addition, Dfi1p is required for full activation of mitogen activated protein kinase Cek1p during growth on agar. In this study, we identified a putative calmodulin binding motif in the C-terminal tail of Dfi1p. This region of Dfi1p bound to calmodulin in vitro, and mutations that affected this region affected both calmodulin binding in vitro and invasive filamentation when incorporated into the full length Dfi1p protein. Moreover, increasing intracellular calcium levels led to calcium-dependent, Dfi1p-dependent Cek1p activation. We propose that conformational changes in Dfi1p in response to environmental conditions encountered during growth allow the protein to bind calmodulin and initiate a signaling cascade that activates Cek1p.

Topics: Agar; Amino Acid Motifs; Amino Acid Sequence; Animals; Antifungal Agents; Calcium; Calmodulin; Candida albicans; Candidiasis; Cell Wall; Disease Models, Animal; Fungal Proteins; Hyphae; Intracellular Space; Mice; Microbial Sensitivity Tests; Molecular Sequence Data; Mutant Proteins; Mutation; Protein Binding; Signal Transduction; Virulence

We have previously reported that agaro-oligosaccharides (AGOs) suppressed the elevated levels of nitric oxide (NO), prostaglandin E₂(PGE₂), and pro-inflammatory cytokines in activated monocytes/macrophages, via heme oxygenase-1 induction. In this report, we initially demonstrated that AGOs intake inhibited NO production in activated peritoneal macrophages. Then, we tested for the ability of AGOs to prevent tumor promotion on the two-stage mouse skin carcinogenesis model. As a result, AGOs feeding led to delayed tumor appearance and decreased tumor number. It is known that PGE₂ is one of key players in carcinogenesis. Thus, we confirmed that PGE₂ production was suppressed by AGOs intake in TPA-induced ear edema model. We also demonstrated that cyclooxygenase-2 and microsomal PGE synthase-1, rate-limiting enzymes in PGE₂ production, were down-regulated by AGOs in human monocytes. Consequently, AGOs are expected to prevent tumor promotion by inhibiting PGE₂ elevation in chronic inflammation site.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Agar; Animals; Antineoplastic Agents; Carcinogens; Cyclooxygenase 2; Dinoprostone; Disease Models, Animal; Edema; Humans; Intramolecular Oxidoreductases; Leukocytes, Mononuclear; Macrophages, Peritoneal; Male; Mice; Mice, Inbred ICR; Nitric Oxide; Nitrites; Oligosaccharides; Prostaglandin-E Synthases; RNA, Messenger; Skin Neoplasms; Tetradecanoylphorbol Acetate

Animal models of microbial diseases in humans are an essential component for determining fulfillment of Koch's postulates and determining how the organism causes disease, host response(s), disease prevention, and treatment. In the case of Helicobacter pylori, establishing an animal model to fulfill Koch's postulates initially proved so challenging that out of frustration a human volunteer undertook an experiment to become infected with H. pylori and to monitor disease progression in order to determine if it did cause gastritis. For the discovery of the organism and his fulfillment of Koch's postulates he and a colleague were awarded the Nobel Prize in Medicine. After H. pylori was established as a gastric pathogen, it took several years before a model was developed in mice, opening the study of the organism and its pathogenicity to the general scientific community. However, while the model is widely utilized, there are a number of difficulties that can arise and need to be overcome. The purpose of this chapter is to raise awareness regarding the problems, and to offer reliable protocols for successfully establishing the H. pylori mouse model.

Topics: Aerobiosis; Agar; Animals; Culture Media; Disease Models, Animal; Helicobacter pylori; Mice; Polymerase Chain Reaction; Species Specificity; Stomach; Urease

We sought to characterise a refined rat model of respiratory infection with P. aeruginosa over an acute time course and test the antibiotic ciprofloxacin.. Agar beads were prepared ± SPAN(®)80. Rats were inoculated with sterile agar beads or those containing 10(5) colony forming units (cfu) P. aeruginosa via intra-tracheal dosing. Bacterial load and inflammatory parameters were measured.. Differing concentrations of SPAN(®) 80 modified median agar bead diameter and reduced particle size distribution. Beads prepared with 0.01% v/v SPAN(®)80 were evaluated in vivo. A stable lung infection up to 7 days post infection was achieved and induced BALF neutrophilia 2 and 5 days post infection. Ciprofloxacin (50mg/kg) significantly attenuated infection without affecting the inflammatory parameters measured.. SPAN(®) 80 can control the particle size and lung distribution of agar beads and P. aeruginosa-embedded beads prepared with 0.01%v/v SPAN(®)80 can induce infection and inflammation over 7 days.

Topics: Acute Disease; Agar; Animals; Anti-Infective Agents; Bacterial Load; Bronchoalveolar Lavage Fluid; Ciprofloxacin; Disease Models, Animal; Hexoses; Leukocyte Count; Male; Microspheres; Neutrophils; Particle Size; Pseudomonas aeruginosa; Pseudomonas Infections; Rats; Rats, Sprague-Dawley; Respiratory Tract Infections; Time Factors; Treatment Outcome

Peritoneal adhesions cause significant long-term postoperative morbidity. This study evaluates the efficacy of agar plates as the physical barrier in reducing adhesion formation after abdominal surgery in an animal model.. Adhesions were induced, by cecum abrasion, in 20 C57/BL6 mice during a laparotomy procedure. Agar plates were used in 10 mice as the experimental group. At a second operation, 28 days later, the adhesions were graded, in two groups. Data were analyzed by using Student t test.. There was no significant difference in weight gain of the two groups during the study period. A comparison of the morphological appearances of the adhesions demonstrated that there was no evident difference between the two groups. There was also no significant difference in the incidence ratio of adhesions or postoperative adhesion scores between the two groups (p value >0.05).. Despite the hydrogel properties of agar, it was not successful in practice in the reduction of adhesion formation after peritoneal surgery. Since agar is a biological product, it may cause a hyperreactivity induced by the innate immune system in peritoneum. Therefore, agar does not appear to be useful in clinical practice for the reduction of adhesion formation after peritoneal surgery.

Topics: Agar; Animals; Disease Models, Animal; Female; Laparotomy; Mice; Mice, Inbred C57BL; Peritoneal Cavity; Postoperative Complications; Random Allocation; Reoperation; Tissue Adhesions

The stringent response is a regulatory system that allows bacteria to sense and adapt to nutrient-poor environments. The central mediator of the stringent response is the molecule guanosine 3',5'-bispyrophosphate (ppGpp), which is synthesized by the enzymes RelA and SpoT and which is also degraded by SpoT. Our laboratory previously demonstrated that a relA mutant of Pseudomonas aeruginosa, the principal cause of lung infections in cystic fibrosis patients, was attenuated in virulence in a Drosophila melanogaster feeding model of infection. In this study, we examined the role of spoT in P. aeruginosa virulence. We generated an insertion mutation in spoT within the previously constructed relA mutant, thereby producing a ppGpp-devoid strain. The relA spoT double mutant was unable to establish a chronic infection in D. melanogaster and was also avirulent in the rat lung agar bead model of infection, a model in which the relA mutant is fully virulent. Synthesis of the virulence determinants pyocyanin, elastase, protease, and siderophores was impaired in the relA spoT double mutant. This mutant was also defective in swarming and twitching, but not in swimming motility. The relA spoT mutant and, to a lesser extent, the relA mutant were less able to withstand stresses such as heat shock and oxidative stress than the wild-type strain PAO1, which may partially account for the inability of the relA spoT mutant to successfully colonize the rat lung. Our results indicate that the stringent response, and SpoT in particular, is a crucial regulator of virulence processes in P. aeruginosa.

Topics: Agar; Animals; Bacterial Load; Bacterial Proteins; Disease Models, Animal; Drosophila melanogaster; Feeding Behavior; Gene Expression Regulation, Bacterial; Guanosine Pentaphosphate; Heat-Shock Response; Humans; Ligases; Lung; Mutation; Pseudomonas aeruginosa; Pseudomonas Infections; Rats; Virulence

The aim of the present study was to evaluate the possibility of studying meningococcal virulence in a new model organism, Dictyostelium discoideum, a haploid social soil amoeba that is an established host model for several human pathogens, leading to the discovery of novel virulence mechanisms.. A number of virulent and hyper-virulent N. meningitidis strains, including isogenic encapsulated, unencapsulated, and lipooligosaccharide (LOS) outer core-defective derivatives, were used to test the ability of D. discoideum to internalize and grow in the presence of bacteria. Intracellular survival of the internalized bacteria was also monitored.. Meningococci were internalized and killed by D. discoideum cells. The presence of a capsule did not affect the internalization, but, as in human cells, it increased the resistance of the internalized bacteria. Although both encapsulated and unencapsulated meningococci supported the growth and development of D. discoideum on an agar surface, in liquid medium the encapsulated strains were toxic to the slime mould cells. Toxicity inversely correlated with meningococcal survival in the assay medium that was not favorable to bacterial replication, suggesting that it may be due to some toxic compound released after bacterial autolysis. Intriguingly, unencapsulated isogenic strains efficiently supported Dictyostelium growth in suspension, opening the possibility that the toxicity may be associated with the capsular polysaccharide.. These results suggest that several meningococcal virulence determinants, such as the capsular polysaccharide, may be remarkably effective also in Dictyostelium cells, stimulating the use of this model host to search for novel meningococcal virulence determinants.

Topics: Agar; Animals; Bacterial Capsules; Culture Media; Dictyostelium; Disease Models, Animal; Endocytosis; Feeding Behavior; Host-Pathogen Interactions; Life Cycle Stages; Lipopolysaccharides; Microbial Viability; Neisseria meningitidis; Phenotype

Quantitation of bacterial load in tissues is essential for experimental investigation of Mycobacterium tuberculosis infection and immunity. We have used an automated liquid culture system to determine the number of colony forming units (CFU) in murine tissues and compared the results to those obtained by conventional plating on Middlebrook agar. There is an overall good correlation between results obtained by the two methods. Although less consistency and more contamination was observed in the automated liquid culture, the method is more sensitive, less labour intensive and allows the processing of large numbers of samples.

Topics: Agar; Animals; Bacteriological Techniques; Colony Count, Microbial; Culture Media; Disease Models, Animal; Female; Humans; Lung; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mycobacterium tuberculosis; Sensitivity and Specificity; Spleen; Tuberculosis, Pulmonary

Hyperthermia has been used in multimodal cancer treatments, and in randomized, controlled studies, hyperthermia is an effective cancer therapy. For clinical accuracy and safety, however, temperature monitoring during treatment is essential. We aimed to develop a convenient microwave hyperthermia system combined with spatially resolved real-time temperature monitoring to improve its efficacy and safety.. Using an MR-compatible irradiation-type microwave applicator, agar phantoms, thigh muscles of rabbit, and subcutaneous VX2 tumors of rabbit were heated in combination with noninvasive MR temperature maps. For MR temperature calculation, a proton resonance frequency method was used. After determination of temperature coefficients and evaluation of the precision in MR thermometry, distribution of microwave heating over time was examined for each substance.. The temperature coefficients of phantoms, rabbit muscles, and VX2 tumors were -0.00977, -0.00976, and -0.01027 ppm/ degrees C, respectively. The 95% limits of agreement of MR and fluoroptic thermometry in the three subjects were +0.318/-0.339 degrees C, +0.693/-0.661 degrees C, and +0.564/-0.526 degrees C, respectively. Concerning VX2 tumor, the average tumor temperature was 42.60 +/- 0.14 degrees C and the surface of skin was 43.27 +/- 0.45 degrees C in the 60-min experimental period.. With this easy-to-use microwave hyperthermia system, effective hyperthermia was accomplished in phantoms and living animals in combination with MR temperature maps.

Topics: Agar; Animals; Disease Models, Animal; Hyperthermia, Induced; Magnetic Resonance Imaging; Male; Microwaves; Muscle, Skeletal; Neoplasm Transplantation; Neoplasms; Rabbits; Subcutaneous Tissue; Temperature; Thermography

Burkholderia cenocepacia is an opportunistic pathogen that can cause severe lung infections in cystic fibrosis patients. To understand the contribution of B. cenocepacia flagella to infection, a strain mutated in the major flagellin subunit, fliCII, was constructed in B. cenocepacia K56-2 and tested in a murine agar bead model of lung infection. C57/BL6 mice infected with approximately 10(8) wild-type K56-2 bacteria exhibited 40% mortality after 3 days, whereas no mortality was noted in mice infected with the fliCII mutant. Among the mice surviving the infection with either strain, there was no significant difference in the bacterial loads in the lungs and spleen, bacteremia, weight loss, or infiltration of immune effector cells at 3 days postinfection. Similar results were observed at 24 h, prior to expression of the lethality phenotype. KC, a murine interleukin-8 (IL-8) homolog, was elevated in both the bronchoalveolar lavage fluid and serum of mice infected with the wild type compared to the fliCII mutant at 24 h, suggesting that flagella stimulated host cells. To demonstrate that flagella contributed to these responses, the interaction between B. cenocepacia and Toll-like receptor 5 (TLR5) was investigated. Infection of HEK293 cells with heat-killed wild-type K56-2, but not infection with the fliCII mutant, resulted in both NF-kappaB activation and IL-8 secretion that was dependent upon expression of TLR5. Together, these results demonstrate that B. cenocepacia flagella contribute to virulence in an in vivo infection model, and that induction of host immune responses through interaction with TLR5 may contribute to its overall pathogenic potential.

Topics: Agar; Animals; Burkholderia cepacia; Burkholderia Infections; Cell Line; Disease Models, Animal; Female; Flagella; Flagellin; Humans; Inflammation; Interleukin-8; Lung Diseases; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Microspheres; Mutation; Receptors, Cell Surface; Toll-Like Receptor 5; Toll-Like Receptors; Virulence

To compare the microbiologic yield of cultures obtained by direct inoculation of blood agar plates (BAP) from corneal ulcer swabbings versus indirect inoculation via transport media in a rabbit model of Streptococcus pneumoniae bacterial keratitis.. The corneas of 12 rabbits were inoculated with S. pneumoniae. Keratitis was confirmed 18 hours later. Sampling was performed at four 2.5-hour intervals. At each interval, corneal swabs were directly applied to BAP and placed into transport medium: thioglycollate and Amies medium without charcoal. Swabbings were then subcultured onto BAP at two time points: 2 and 24 hours after collection in transport medium. Plates were evaluated 48 hours later. Organism recovery rates were measured in terms of the number of positive culture plates observed and the bacterial colony counts on each plate.. The rate of positive cultures overall was 69%. The recovery rates were similar for direct inoculation, inoculation via Amies held for 2 hours, and inoculation via Amies held for 24 hours. Direct inoculation yielded fewer colonies than indirect inoculation via Amies held for 24 hours (p = 0.008). Direct inoculation yielded a higher rate of positive cultures than did thioglycollate held for 2 hours (p = 0.004) or 24 hours (p < 0.001). The rate of nonpneumococcal contaminants ranged from 6% of BAP subcultured from thioglycollate held for 24 hours to 28% of directly inoculated BAP.. Amies medium without charcoal may be used as a transport medium for up to 24 hours in the recovery of S. pneumoniae from corneal ulcers in this rabbit model. Thioglycollate appears to be less effective as a transport medium. Results of this study may justify studies of other transport media and/or other corneal pathogens. Altogether, such studies may provide justification for human clinical trials.

Topics: Agar; Animals; Bacteriological Techniques; Culture Media; Disease Models, Animal; Eye Infections, Bacterial; Keratitis; Rabbits; Specimen Handling; Streptococcal Infections; Streptococcus pneumoniae

Two surface-active compounds, egg lecithin and polysorbate 80, usually used as the deactivators of various preservatives were tested whether they also counteract either or all of the three major topical antifungal drugs, bifonazole (BFZ), lanoconazole (LCZ) and terbinafine (TBF). Both egg lecithin and polysorbate 80, when added to culture media up to final concentrations of 1.0 and 0.7%, respectively, antagonized the anti-dermatophytic activity of the three drugs in a concentration-dependent manner. A greater extent of antagonistic action was exerted when the two deactivators combined at their maximal levels tested were added; MIC's of BFZ were increased more than 30-fold and those of LCZ and TBF more than 200-fold compared with the values obtained in the absence of the deactivators. Using the agar medium supplemented with the combined deactivators, culture studies were carried out with skin tissues specimens taken from guinea pigs whose feet were infected with dermatophytes and subsequently treated with 1% topical preparations of the three antifungal drugs. The experimental data from this animal study demonstrated that the combined deactivators-supplemented medium yielded increased numbers of fungi compared with the basal medium. It looks, therefore, likely that the fungal recovery on the former medium more correctly reflects to actual fungal burden in the infected lesions than the latter. All these results suggest that the combined deactivators-supplemented medium is more useful for mycological evaluation of therapeutic efficacy of imidazole and allylamine drugs against dermatophytoses in both preclinical and clinical studies.

Topics: Administration, Topical; Agar; Animals; Antifungal Agents; Culture Media; Disease Models, Animal; Female; Guinea Pigs; Heterocyclic Compounds; Imidazoles; Microbiological Techniques; Naphthalenes; Phosphatidylcholines; Polysorbates; Surface-Active Agents; Terbinafine; Tinea Pedis; Trichophyton

The minimum inhibitory doses (MIDs) of essential oils by vapour contact to inhibit the growth of Trichophyton mentagrophytes and Trichophyton rubrum on agar medium were determined using airtight boxes. Among seven essential oils examined, cinnamon bark oil showed the least MID, followed by lemongrass, thyme and perilla oils. Lavender and tea tree oils showed moderate MID, and citron oil showed the highest MID, being 320 times higher than that of cinnamon bark oil. The MID values were less than the minimum inhibitory concentration (MIC) values determined by agar dilution assay. Furthermore, the minimum agar concentration (MAC) of essential oils absorbed from vapour was determined at the time of MID determination as the second antifungal measure. The MAC value by vapour contact was 1.4 to 4.7 times less than the MAC remaining in the agar at the time of MIC determination by agar dilution assay. Using selected essential oils, the anti-Trichophyton activity by vapour contact was examined in more detail. Lemongrass, thyme and perilla oils killed the conidia, inhibited germination and hyphal elongation at 1-4 micrograms ml-1 air, whereas lavender oil was effective at 40-160 micrograms ml-1 air. The in-vivo efficacy of thyme and perilla oils by vapour contact was shown against an experimental tinea pedis in guinea pigs infected with T. mentagrophytes. These results indicated potent anti-Trichophyton action of essential oils by vapour contact.

Topics: Agar; alpha-Linolenic Acid; Animals; Antifungal Agents; Aromatherapy; Culture Media; Disease Models, Animal; Dose-Response Relationship, Drug; Guinea Pigs; Lamiaceae; Lavandula; Male; Microbial Sensitivity Tests; Oils, Volatile; Phytotherapy; Plant Oils; Terpenes; Tinea Pedis; Trichophyton

Helicobacter pylori infection in humans is associated with chronic type B gastritis, peptic ulcer disease, and gastric carcinoma. A high intake of carotenoids and vitamin C has been proposed to prevent development of gastric malignancies. The aim of this study was to explore if the microalga Haematococcus pluvialis rich in the carotenoid astaxanthin and vitamin C can inhibit experimental H. pylori infection in a BALB/cA mouse model. Six-week-old BALB/cA mice were infected with the mouse-passaged H. pylori strain 119/95. At 2 weeks postinoculation mice were treated orally once daily for 10 days (i) with different doses of algal meal rich in astaxanthin (0.4, 2, and 4 g/kg of body weight, with the astaxanthin content at 10, 50, and 100 mg/kg, respectively), (ii) with a control meal (algal meal without astaxanthin, 4 g/kg), or (iii) with vitamin C (400 mg/kg). Five mice from each group were sacrificed 1 day after the cessation of treatment, and the other five animals were sacrificed 10 days after the cessation of treatment. Culture of H. pylori and determination of the inflammation score of the gastric mucosae were used to determine the outcome of the treatment. Mice treated with astaxanthin-rich algal meal or vitamin C showed significantly lower colonization levels and lower inflammation scores than those of untreated or control-meal-treated animals at 1 day and 10 days after the cessation of treatment. Lipid peroxidation was significantly decreased in mice treated with the astaxanthin-rich algal meal and vitamin C compared with that of animals not treated or treated with the control meal. Both astaxanthin-rich algal meal and vitamin C showed an inhibitory effect on H. pylori growth in vitro. In conclusion, antioxidants may be a new strategy for treating H. pylori infection in humans.

Topics: Agar; Animals; Ascorbic Acid; beta Carotene; Carotenoids; Disease Models, Animal; Helicobacter Infections; Helicobacter pylori; Lipid Peroxidation; Mice; Mice, Inbred BALB C; Xanthophylls

Topics: Adolescent; Agar; Animals; Body Temperature; Bone and Bones; Catheter Ablation; Disease Models, Animal; Female; Follow-Up Studies; Hemangiopericytoma; Humans; Liver; Longitudinal Ligaments; Lumbar Vertebrae; Male; Middle Aged; Osteoma, Osteoid; Radiography, Interventional; Spinal Canal; Spinal Neoplasms; Swine; Temperature; Thermometers; Tomography, X-Ray Computed

We describe a novel mouse model of acute staphylococcal pneumonia induced by intravenous injection of Staphylococcus aureus enmeshed in agar beads. For comparison, we also used various strains of bacteria, including three strains of S. aureus, two strains of Staphylococcus epidermidis, one strain of Streptococcus pyogenes, three strains of Pseudomonas aeruginosa, and one strain of Klebsiella pneumoniae. All except two strains of S. aureus were cleared rapidly from the lungs. When S. aureus NUMR1 enmeshed in agar beads was injected intravenously, the organisms concentrated and remained in the lung for a period longer than several weeks. Multiple lung abscesses were evident macroscopically, and histological examination of the infected lung showed multiple lung abscesses around the pulmonary arterioles, consisting of bacterial colonies encircled with fibrin filaments and surrounded by inflammatory cells of neutrophils and macrophages. When 14 strains of clinically isolated S. aureus were injected intravenously, the number of bacteria recovered from the lung tissue 7 days after infection correlated with the titer of staphylocoagulase (P < 0.01) but not with the titer of clumping factor. Injection of coagulase-deficient mutant strain DU5843 was associated with a markedly reduced number of viable bacteria isolated from the lung, compared with its coagulase-positive parental strain DU5789. Our results suggest that coagulase may play a role in the development of blood-borne staphylococcal pneumonia in our model. Our animal model is simple and reproducible and resembles blood-borne staphylococcal pneumonia in humans, and it could be useful for investigating the pathogenicity or treatment of staphylococcal pulmonary infection, including infections with methicillin-resistant S. aureus.

Topics: Agar; Animals; Bacteremia; Coagulase; Colony Count, Microbial; Disease Models, Animal; Injections, Intravenous; Lung; Male; Mice; Mice, Inbred Strains; Microspheres; Pneumonia, Staphylococcal; Staphylococcal Infections; Staphylococcus aureus

Prior attempts to create an animal model of empyema by direct inoculation of bacteria alone into the pleural space have been unsuccessful. The animals either died of overwhelming sepsis or cleared the infection from the pleural space without development of an empyema. We hypothesized that injection of bacteria with a nutrient agar into the pleural space would allow the bacteria to remain in the pleural space for an extended time period, permitting an empyema to develop. The bacterium Pasteurella multocida in brain heart infusion (BHI) agar was injected into the right hemithorax of 12 New Zealand white male rabbits. Our preliminary studies showed that the animals died in less than 7 days if they were not given parenteral antibiotics. For this reason, the rabbits were given penicillin, 200,000 U, IM, every 24 h starting 24 h after bacterial injection. Pleural fluid was sampled by thoracentesis at 12, 24, 48, 72, and 96 h after bacterial injection. Pleural fluid pH, glucose, lactate dehydrogenase (LDH), leukocyte count, and Gram's stain and culture (in one half of the animals) were obtained at each time point. Pleural biopsy specimens were obtained at autopsy after 96 h. The mean pleural fluid pH reached a nadir of 7.01 at 24 h and remained less than 7.1 throughout the experiment. The mean pleural fluid glucose level reached a nadir of 10 mg/dL at 24 h. The mean pleural fluid LDH peaked at 21,000 IU/L at 24 h and the mean pleural fluid leukocyte count peaked at 12 h with a value of 67,000 cells per cubic millimeter. Gram's stains revealed organisms and cultures were positive for growth in all animals at 12 and 24 h. Some animals had positive Gram's stains and growth on cultures up to 72 h after bacterial injection. At autopsy, all rabbits injected with bacteria had gross pus in the right pleural space and had developed a thick pleural peel. Microscopic specimens of the pleura revealed large numbers of leukocytes (primarily polymorphonuclear lymphocytes) with invasion of the adjacent lung and chest wall. In conclusion, this model more closely mimics the empyema that occurs in humans, relative to previous animal models. This model appears appropriate for additional randomized studies in which different methods for the treatment of empyema can be evaluated.

Topics: Agar; Animals; Biopsy; Culture Media; Disease Models, Animal; Empyema, Pleural; Glucose; Hydrogen-Ion Concentration; Injections, Intramuscular; L-Lactate Dehydrogenase; Leukocyte Count; Lung; Male; Neutrophils; Pasteurella Infections; Pasteurella multocida; Penicillins; Pleura; Pleural Effusion; Rabbits; Thorax

The aim of the study was to evaluate the effects of two kinds of Chinese medicinal herbs, Isatis tinctoria L (ITL) and Daphne giraldii Nitsche (DGN), on a rat model of chronic Pseudomonas aeruginosa lung infection mimicking cystic fibrosis (CF). Compared to the control group, both drugs were able to reduce the incidence of lung abscess (p < 0.05) and to decrease the severity of the macroscopic pathology in lungs (p < 0.05). In the great majority of the rats, the herbs altered the inflammatory response in the lungs from an acute type inflammation, dominated by polymorphonuclear leukocytes (PMN), to a chronic type inflammation, dominated by mononuclear leukocytes (MN). DGN also improved the clearance of P. aeruginosa from the lungs (p < 0.03) compared with the control group. There were no significant differences between the control group and the two herbal groups with regard to serum IgG and IgA anti-P. aeruginosa sonicate antibodies. However, the IgM concentration in the ITL group was significantly lower than in the control group (p < 0.03). These results suggest that the two medicinal herbs might be helpful to CF patients with chronic P. aeruginosa lung infection, DGN being the most favorable.

Topics: Agar; Animals; Antibodies, Bacterial; Chronic Disease; Culture Media; Cystic Fibrosis; Disease Models, Animal; Drugs, Chinese Herbal; Female; Lung Diseases; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas Infections; Rats; Rats, Inbred Lew

Propionibacterium acnes has been identified as a significant agent of nosocomial infections, including endophthalmitis. Data concerning susceptibility of P. acnes to newer beta-lactam antibiotics and fluoroquinolones are limited. Recent reports suggest that quinolones have activity against these organisms sufficient to warrant further study. We undertook a study to select appropriate antimicrobial agents for use in a rabbit model of P. acnes endophthalmitis. We compared the antibiotic susceptibilities of P. acnes by using the National Committee for Clinical Laboratory Standards method of agar dilution with the E test. Thirteen clinical isolates obtained from eye specimens and three American Type Culture Collection control strains were tested against 14 antibiotics. All the clinical isolates were susceptible by both methods to piperacillin, piperacillin-tazobactam, ampicillin-sulbactam, ticarcillin-clavulanate, cefotaxime, cefotetan, ceftriaxone, cefoxitin, and imipenem in addition to clindamycin but were resistant to metronidazole. The clinical P. acnes isolates also displayed high-level susceptibility to ciprofloxacin, sparfloxacin, and ofloxacin. Almost all the P. acnes strains demonstrated E-test MICs within 2 dilutions of the MICs observed by the agar dilution method. Those few strains for which discrepancies were noted exhibited E-test susceptibilities three- to fivefold dilutions lower than the agar dilution method susceptibilities but only with ampicillin-sulbactam, ticarcillin-clavulanate, and/or clindamycin. On the basis of our study, all of clinical eye isolates were susceptible to these newer antimicrobial agents and the two methods demonstrated similar susceptibility patterns.

Topics: Agar; Animals; Anti-Bacterial Agents; Anti-Infective Agents; Cross Infection; Disease Models, Animal; Endophthalmitis; Fluoroquinolones; Gram-Positive Bacterial Infections; Humans; Lactams; Microbial Sensitivity Tests; Propionibacterium acnes; Rabbits

The usefulness and safety of water jet angioplasty was studied in vitro, using agar phantom and autopsied aorta, and in vivo in acute and chronic arterial occlusions in mongrel dogs. At an injection rate of 1.0 ml/s, the water jet produced erosion of the agar surface when the distance between the catheter and the agar was 1 mm. With an injection rate of 1.5 ml/s, erosion was produced at a distance of 15 mm from the catheter tip. When the water jet was directed at an arterial wall, intimal ablation and ruptured elastic fibers were found histopathologically. A smaller angle between the vascular wall and the catheter was associated with less vascular damage. In vivo, water jet angioplasty was effective against acute obstructions, but not against chronic obstructions. These results suggest that water jet angioplasty may be effective against arterial obstruction due to acute thrombus.

Topics: Agar; Angioplasty, Balloon; Animals; Aorta; Disease Models, Animal; Dogs; Equipment Design; Evaluation Studies as Topic; Femoral Artery; Humans; In Vitro Techniques; Models, Structural; Polyethylenes; Radiography, Interventional; Thrombosis; Water

Alginate-producing, mucoid P. aeruginosa is frequently found in the lungs of patients with cystic fibrosis (CF), where it causes a chronic infection. The importance of alginate in the pathogenesis was demonstrated by the ability to establish chronic P. aeruginosa lung infection in rats if P. aeruginosa entrapped in minute alginate-beads were inoculated transtracheally. Alginate beads containing P. aeruginosa were formed by nebulizing a suspension of seaweed sodium-alginate and P. aeruginosa into a calcium solution. The alginate bead method of establishing infection was compared to an agar-bead method and proved to be quantitatively similar after 4 weeks. The ability of the two methods to induce formation of precipitins, IgA and IgG antibodies against P. aeruginosa antigens, including outer membrane proteins, flagella, exoenzymes and alginate, was assessed by crossed immunoelectrophoresis, enzyme-linked immunosorbent assay and immunoblotting. The two methods of inducing infection were comparable and infected rats had significantly higher antibody response than rats inoculated with sterile beads. We suggest that the alginate bead model closely resembles the later stages of CF-lung infection and that it offers the theoretical advantage of using a substance which is chemically similar to the alginate produced in vivo by P. aeruginosa.

Topics: Agar; Alginates; Animals; Antigens, Bacterial; Disease Models, Animal; Female; Microspheres; Pneumonia; Pseudomonas aeruginosa; Pseudomonas Infections; Rats; Rats, Inbred Strains

The important requirements of a skin substitute such as water vapour permeability, adherence to the excised wound surface, oxygen permeability, mechanical properties, impermeability to micro-organisms and exudate soaking capacity have been highlighted. Two commercial synthetic skin substitutes, Bioclusive and Geliperm, have been used to establish the preclinical assessment procedures for skin substitutes. Two in vitro techniques, the 'Water Cup' and the 'Inverted Cup,' and two in vivo methods involving a 'Ventilated Hygrometer Chamber' system and an Evaporimeter have been employed to assess and compare the water vapour permeability of the skin substitutes under controlled conditions. An Evaporimeter, which is very simple to operate, provides more accurate results. A simple test has been designed to evaluate the early adherence of the skin substitutes to the excised wound surface of rats. The pulling force and the peeling force required to remove the membrane from the wound surface have been measured and these forces have been found to depend upon the composition of the membrane. An oxygen permeability cell has been fabricated which measures the dissolved oxygen permeability of the skin substitutes. The detection of oxygen is based on the electrocatalytic reduction of oxygen at the surface of a noble metal. The tensile properties of the skin substitutes have been measured by an International Standard procedure and both the skin prostheses are associated with some drawbacks. An in vitro method of testing the microbial permeability of the skin substitutes has been designed which simulates an oozing colonized wound that a skin substitute faces in cases of septicaemia. Both the test materials were impermeable to both bacteria and fungi and will provide an effective barrier. The effectiveness of the skin substitutes to absorb wound exudate from the wound surface has been evaluated by soaking the pieces of the membranes in water, plasma and serum and observing their weight gain. The soaking capacity depends upon the composition and nature of the material. The procedures developed have been employed to evaluate a hydrogel type synthetic skin substitute recently formulated in our laboratory.

Topics: Acrylamides; Agar; Animals; Burns; Disease Models, Animal; Evaluation Studies as Topic; Permeability; Prostheses and Implants; Rats; Rats, Inbred Strains; Skin; Water Loss, Insensible; Wound Healing

Bromelain is a plant proteinase derived from the stem of the pineapple plant that has been used successfully to debride the eschar from third-degree burn injuries. Its applicability to frostbite eschar removal was extrapolated and investigated. Third-degree frostbite lesions were produced on swine using supercooled air as the freezing media, and the resulting eschars were treated with a bromelain preparation. In the initial trial, no debridement other than that of the superficial layers of the eschar was noted. The experiment then was repeated with the introduction of third-degree burn injuries as a control to validate the efficacy of the enzyme preparation. Although the burn injuries debrided to a graftable bed after two applications of the enzyme, the frostbite injuries remained unaffected. It was concluded that the patent vasculature, resulting tissue edema, and lack of coagulation of proteins found in the freeze injury are sufficient to inactivate the bromelain enzyme before tissue digestion and dissection can be effected.

Topics: Agar; Animals; Bromelains; Debridement; Disease Models, Animal; Evaluation Studies as Topic; Frostbite; Gels; Male; Swine; Swine, Miniature; Time Factors

The development of a pure Bacteroides fragilis infection in mice is described. The infection produces large subcutaneous abscesses at the site of injection which can be observed grossly within 7 days after injection. The infection was initiated by infection of pure cultures grown in semisolid agar medium. Similar infections were also produced with pure cultures of B. distasonis, B. ovatus, B. thetaiotaomicron, and B. vulgatus. However, a distinct deoxyribonucleic acid homology group, formerly classified as B. thetaiotaomicron, did not produce abscesses in any of the mice tested.

Topics: Agar; Animals; Bacteroides; Bacteroides fragilis; Bacteroides Infections; Base Sequence; Disease Models, Animal; DNA, Bacterial; Male; Mice

The method of intrapulmonary infection of guinea pigs was suggested for the assessment of the virulent properties of cholera vibrios. Addition into the diluent of 10% peptone, 10% gelatine and 0.05% agar-agar led to the reduction of LD50 by over 1000 times. A specific infectious process coursing in an acute generalized form with bacteriemia and affection of the small intestine developed in the infected animals. The majority of the animals perished in 1 to 2 days.

Topics: Agar; Animals; Cholera; Disease Models, Animal; Gelatin; Guinea Pigs; Lethal Dose 50; Peptones; Vibrio cholerae; Virulence

No growth of Coccidioides immitis occurred when fluid from infected tissue or arthrospores suspended in distilled water were plated on the surface of Sabouraud medium, solidified with refined agar, and containing 20 mg of polymyxin B per liter. Solidification of Sabouraud medium with unrefined agar completely abolished the anticoccidioidal activity of polymyxin B.

Topics: Agar; Animals; Coccidioides; Coccidioidomycosis; Disease Models, Animal; Lung; Polymyxins

Difficulty is frequently experienced in producing a large homogeneous myocardial infarct in the dog heart because of the extensive network of coronary anastomoses. This problem may be overcome by combining the ligation of the left anterior descending coronary artery with agar injection into the distal coronary vasculature to obliterate anastomotic channels. All infarcts produced in this manner occupied a constant area in the anterior wall of the left ventricle. From our results in 25 dogs, the individual infarct averaged 12.3 Gm. in weight (range 9.4 to 13.5), representing 25 to 30 per cent of the total left ventricular muscle mass. The homogeneity of the infarct was verified by a simple, macroscopic enzyme-mapping technique based on the inability of the ischemic (dehydrogenase-deficient) myocardium to reduce triphenyl tetrazolium chloride and by detailed histologic studies. Apart from providing ample raw material for comprehensive morphologic, chemical, histochemical, and radioisotopic analyses, a large myocardial infarct also serves as a useful experimental model for various physiological and hemodynamic studies of cardiogenic shock and left ventricular akinesis.

Topics: Agar; Animals; Arteries; Coronary Vessels; Disease Models, Animal; Dogs; Electrocardiography; Hemodynamics; Injections, Intra-Arterial; Ligation; Myocardial Infarction; Myocardium; Oxidoreductases; Shock, Cardiogenic; Tetrazolium Salts

Topics: Agar; Animals; Arteries; Coronary Vessels; Disease Models, Animal; Dogs; Heart Failure; Heart Ventricles; Hemodynamics; Ligation; Methods; Myocardial Infarction; Myocardium; Radiography, Thoracic; Time Factors; Ventricular Fibrillation

Topics: Agar; Animals; Carbohydrate Metabolism; Cell Fractionation; Cytoplasm; Disease Models, Animal; Fatty Acids; Lethal Dose 50; Lipid Metabolism; Male; Mice; Nafcillin; Nitrogen; Organ Specificity; Oxidative Phosphorylation; Oxygen Consumption; Proteins; Staphylococcal Infections; Staphylococcus; Toxins, Biological

Topics: Agar; Animals; Brain; Cerebral Cortex; Cobalt; Disease Models, Animal; Electroencephalography; Epilepsy; Gelatin; Male; Olfactory Bulb; Polyethylenes; Potassium; Rats; Seizures; Sodium; Stereotaxic Techniques; Waxes

Topics: Agar; Animals; Antineoplastic Agents; Carcinoma; Cell Line; Cells, Cultured; Disease Models, Animal; Humans; Leukemia L1210; Melanoma; Mice; Mice, Inbred Strains; Mouth Neoplasms; Neoplasm Transplantation; Neoplasms, Experimental; Oncogenic Viruses; Plant Extracts

Topics: Acridines; Agar; Animals; Blood; Conjugation, Genetic; Disease Models, Animal; Escherichia coli; Genes; Genetics, Microbial; Glucose; Guinea Pigs; Hybridization, Genetic; Keratoconjunctivitis; Mucous Membrane; Sheep; Shigella; Species Specificity; Urinary Bladder Diseases; Urinary Tract Infections; Virulence

Topics: Agar; Agglutination Tests; Animals; Antigens, Bacterial; Blood; Culture Media; Disease Models, Animal; Escherichia coli; Genetics, Microbial; Glucose; Guinea Pigs; Hemolysis; Humans; Immune Sera; Keratoconjunctivitis; Mucous Membrane; Mutation; Oxygen; Quaternary Ammonium Compounds; Rabbits; Sheep; Shigella; Species Specificity; Virulence

Topics: Agar; Animals; Animals, Laboratory; Arthritis, Infectious; Cricetinae; Culture Media; Culture Techniques; Disease Models, Animal; Freund's Adjuvant; Guinea Pigs; Injections; Injections, Intraperitoneal; Lymphoma, Non-Hodgkin; Methylcellulose; Mice; Mucins; Mycoplasma; Mycoplasma Infections; Rabbits; Rats; Sarcoma, Experimental; Sepsis; Silicon Dioxide; Talc; Virulence