exudates and Dysentery--Bacillary

Shigella is an intracellular bacterial pathogen that causes bacterial dysentery called shigellosis. The assessment of pro- and anti-inflammatory mediators produced by immune cells against this bacteria are vital in identifying the effectiveness of the immune reaction in protecting the host. In Malaysia, Shigella is ranked as the third most common bacteria causing diarrheal disease among children below 5 years old. In the present study, we aim to examine the differential cytokine gene expressions of macrophages in response to two types of clinical strains of Shigella flexneri 2a (S. flexneri 2a) isolated from patients admitted in Hospital Universiti Sains Malaysia, Kelantan, Malaysia. THP-1-derived macrophages, as the model of human macrophages, were infected separately with S. flexneri 2a mild (SH062) and virulence (SH057) strains for 6, 12, and 24 h, respectively. The gene expression level of inflammatory mediators was identified using real-time quantitative polymerase chain reaction (RT-qPCR). The production of nitric oxide (NO) by the macrophages was measured by using a commercialized NO assay kit. The ability of macrophages to kill the intracellular bacteria was assessed by intracellular killing assay. Induction of tumor necrosis factor-alpha (TNFα), interleukin (IL)-1β, IL-6, IL-12, inducible NO synthase (iNOS), and NO, confirmed the pro-inflammatory reaction of the THP-1-derived macrophages in response to S. flexneri 2a, especially against the SH507 strain. The SH057 also induced a marked increase in the expression levels of the anti-inflammatory cytokine mRNAs at 12 h and 24 h post-infection. In the intracellular killing assay, both strains showed less viable, indicating the generation of pro-inflammatory cytokines in the presence of iNOS and NO was crucial in the stimulation of macrophages for the host defense against shigellosis. Transcription analysis of THP-1-derived macrophages in this study identifies differentially expressed cytokine genes that correlated with the virulence factor of S. flexneri 2a.

Topics: Animals; Child, Preschool; Cytokines; Disease Models, Animal; Dysentery, Bacillary; Female; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genetic Variation; Genotype; Humans; Infant; Infant, Newborn; Macrophages; Malaysia; Male; Shigella flexneri; Virulence; Virulence Factors

Shigellosis is a major public health concern worldwide, especially in developing countries. It is an acute intestinal infection caused by bacteria of the genus Shigella, with a minimum infective dose as low as 10-100 bacterial cells. Increasing prevalence of Shigella sonnei as the etiologic agent of shigellosis in Malaysia has been reported. As there is limited information on the genetic background of S. sonnei in Malaysia, this study aimed to characterize Malaysian S. sonnei and to evaluate the prospect of using multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) for subtyping of local S. sonnei.. Forty non-repeat clinical strains of S. sonnei isolated during the years 1997-2000, and 2007-2009 were studied. The strains were isolated from stools of patients in different hospitals from different regions in Malaysia. These epidemiologically unrelated strains were characterized using biotyping, antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE) and MLVA.. The two biotypes identified in this study were biotype a (n = 29, 73%) and biotype g (n = 11, 27%). All the 40 strains were sensitive to kanamycin, ceftriaxone and ciprofloxacin. Highest resistance rate was observed for streptomycin (67.5%), followed by tetracycline (40%) and trimethoprim-sulfamethoxazole (37.5%). All the S. sonnei biotype g strains had a core resistance type of streptomycin - trimethoprim-sulfamethoxazole - tetracycline whereas the 29 biotype a strains were subtyped into eight resistotypes. All the strains were equally distinguishable by PFGE and MLVA. Overall, PFGE analysis indicated that S. sonnei biotype a strains were genetically more diverse than biotype g strains. Cluster analysis by MLVA was better in grouping the strains according to biotypes, was reflective of the epidemiological information and was equally discriminative as PFGE.. The S. sonnei strains circulating in Malaysia throughout the period studied were derived from different clones given their heterogeneous nature. MLVA based on seven selected VNTR loci was rapid, reproducible and highly discriminative and therefore may complement PFGE for routine subtyping of S. sonnei.

Topics: Anti-Bacterial Agents; Bacterial Typing Techniques; Cluster Analysis; Dysentery, Bacillary; Electrophoresis, Gel, Pulsed-Field; Feces; Genotype; Hospitals; Humans; Malaysia; Microbial Sensitivity Tests; Molecular Epidemiology; Molecular Typing; Multilocus Sequence Typing; Prevalence; Shigella sonnei

Topics: Adolescent; Dysentery, Bacillary; Humans; Japan; Malaysia; Male; Schools; Shigella sonnei; Singapore; Travel

There is an increasing trend for Shigella isolates worldwide to be resistant to commonly prescribed antibiotics. The species distribution and antibiotic resistance of Shigella species isolated from children in Kuala Lumpur, Malaysia from 1978 to 1997 was reviewed. Three hundred and eighty six isolates were positive for Shigella species, representing 1.4% (95% CI: 1.3%-1.6%) of the 26320 total stool specimens and 13% (95% CI: 11.8%-14.2%) of 2986 isolates positive for bacterial pathogens. Shigella flexneri, constituting 74% of all isolates in the first five years of the study, decreased by 40% during the last five years (95% CI of decrease: 22.1%-57.9%), p-value < 0.0001) to 34%. There was a significant reduction (chi2 for linear trend = 77.6, p-value < 0.001) in the number of Shigella isolates as a percentage of total stool isolates obtained. 58% of the 241 isolates tested for antibiotic sensitivity were resistant to at least one antibiotic, and 42% wEre multi-resistant to three or more antibiotics. Shigella species was not a common pathogen among children admitted with diarrhoea in Kuala Lumpur, and was more likely to be resistant to commonly prescribed antibiotics.

Topics: Acute Disease; Adolescent; Child; Drug Resistance, Bacterial; Dysentery, Bacillary; Feces; Hospitals, Urban; Humans; Malaysia; Shigella; Time Factors; Urban Population

Topics: Drug Resistance, Microbial; Drug Resistance, Multiple; Dysentery, Bacillary; Humans; Malaysia; Microbial Sensitivity Tests; Prevalence; Shigella

Amongst 107 diarrheal cases studied a bacterial agent was isolated from 71 (66%) cases of which 60 (85%) were due to a single agent and the remaining 11 (15%) were of mixed infections. Enterotoxigenic Escherichia coli (ETEC) was isolated from 65 cases. Other pathogens isolated included Salmonella spp, Shigella spp and rotavirus. There was a higher isolation rate of ETEC from females and rotavirus from males. The infection rate was found to higher for the 0-2 year age group as compared to the 3-5 year age group. Amongst the ETEC isolated the STa 2 toxotype was the predominant type.

Topics: Child, Preschool; Developing Countries; Diarrhea, Infantile; Dysentery, Bacillary; Escherichia coli Infections; Escherichia coli O157; Female; Humans; Infant; Malaysia; Male; Rotavirus Infections; Salmonella Infections

Topics: Child, Preschool; Dysentery, Bacillary; Female; Humans; Malaysia; Shigella flexneri; Vulvovaginitis

Topics: Anti-Bacterial Agents; Diarrhea; Drug Resistance, Microbial; Dysentery, Bacillary; Feces; Humans; Malaysia; Microbial Sensitivity Tests; Serotyping; Shigella

Topics: Dysentery, Bacillary; Feces; Humans; Malaysia; Serotyping; Shigella; Time Factors

Topics: Age Factors; Animals; Animals, Laboratory; Anti-Bacterial Agents; Chloramphenicol; Diarrhea; Dysentery, Bacillary; Feces; Female; Haplorhini; Indonesia; Japan; Macaca; Malaysia; Male; Monkey Diseases; Philippines; Quarantine; Rifampin; Seasons; Shigella flexneri; Shigella sonnei

Topics: Amebiasis; Anemia, Hypochromic; Anthelmintics; Ascariasis; Child; Child, Preschool; Dysentery; Dysentery, Bacillary; Feces; Female; Giardiasis; Humans; Infant; Malaysia; Male; Parasite Egg Count; Pyridinium Compounds; Pyrrolidines; Rectal Prolapse; Salmonella Infections; Sigmoidoscopy; Styrenes; Thiabendazole; Trichuriasis

Topics: Adult; Aeromonas; Diagnosis, Differential; Diarrhea; Dysentery, Bacillary; Humans; Malaysia; Male; Shigella; Shigella sonnei; Typhoid Fever