meropenem and Bacteroides-Infections

To describe the first known case of Bacteroides spp. related blebitis, keratitis, and endophthalmitis following uncomplicated trabeculectomy.. This was a case report and literature review.. A 63-year-old immunocompetent white male underwent uncomplicated trabeculectomy of his right eye. Two weeks later, a blebitis with adjacent keratitis was diagnosed, progressing over several days to endophthalmitis despite hourly topical fortified antibiotic therapy. Although gram stain and culture of the bleb surface, a conjunctival suture, the aqueous humor, and the vitreous were negative, topical real-time quantitative polymerase chain reaction testing disclosed the presence of Bacteroides spp. Following treatment with topical and intravitreal clindamycin and intravenous meropenem, all clinical evidence of infection resolved. Best spectacle-corrected visual acuity improved to 20/25 (0.8) subsequent to combined cataract extraction, intraocular lens implantation, and pars plana vitrectomy for persistent vitreous debris.. Bacteroides may be a rare cause of postoperative blebitis, keratitis, and endophthalmitis. A favorable outcome may be attained, provided that an accurate diagnosis and effective treatment can be provided, which may be facilitated by real-time quantitative polymerase chain reaction in select cases.

Topics: Administration, Ophthalmic; Anti-Bacterial Agents; Bacteroides; Bacteroides Infections; Clindamycin; Corneal Ulcer; Drug Therapy, Combination; Endophthalmitis; Eye Infections, Bacterial; Glaucoma, Open-Angle; Humans; Injections, Intravenous; Intravitreal Injections; Male; Meropenem; Middle Aged; Real-Time Polymerase Chain Reaction; Trabeculectomy

Bacteroides spp. are the most common anaerobic bacteria isolated from the human gastrointestinal tract. Several resistant genes are present in Bacteroides spp. However, most studies have focused on the prevalence of the cfiA gene in Bacteroides fragilis alone. We assessed the susceptibility to antimicrobial agents and the prevalence of cepA, cfiA, cfxA, ermF, nim, and tetQ genes in Bacteroides strains isolated from clinical specimens in our hospital.. We isolated 86 B. fragilis and 58 non-fragilis Bacteroides strains from human clinical specimens collected from January 2011 to November 2021. Resistance against piperacillin (PIPC), cefotaxime (CTX), cefepime (CFPM), meropenem (MEPM), clindamycin, and minocycline was determined.. The resistant rates of penicillins and cephalosporins in non-fragilis isolates were significantly higher than those in B. fragilis isolates. In B. fragilis isolates, the resistant rates of PIPC, CTX, and CFPM in cfxA-positive isolates were significantly higher than those in cfxA-negative isolates (71% vs. 16%, 77% vs. 19%, and 77% vs. 30%, respectively). Thirteen B. fragilis isolates harbored the cfiA gene, two of which were resistant to MEPM. Six of the 13 cfiA-positive B. fragilis isolates were heterogeneously resistant to MEPM.. It is important to evaluate the use of MEPM as empirical therapy for Bacteroides spp. infections, considering the emergence of carbapenem resistance during treatment, existence of MEPM-resistant strains, and heterogeneous resistance.

Topics: Anti-Bacterial Agents; Bacteroides; Bacteroides Infections; Drug Resistance, Bacterial; Humans; Japan; Meropenem; Microbial Sensitivity Tests; Prevalence

Antimicrobial susceptibilities of 4973 Bacteroides spp. isolates recovered from various sources of patients from 12 countries (99.6% from European countries) in the Antimicrobial Testing Leadership and Surveillance (ATLAS) programme, 2007-2020, were investigated. The minimum inhibitory concentrations (MICs) of the isolates with six commonly used agents were determined using the agar dilution method. Among the isolates, 10 Bacteroides spp. were included: B. fragilis (n=3180, 64.0%) was encountered most frequently, followed by B. thetaiotaomicron (n=675) and B. ovatus (n=409). During the 14 years, the proportion of B. fragilis declined, but the proportion of non-fragilis Bacteroides spp. increased. More than 90% of the isolates tested were susceptible to piperacillin-tazobactam, meropenem and tigecycline. Significantly lower susceptibility rates to cefoxitin (P<0.001), clindamycin (P<0.001), piperacillin/tazobactam (P<0.001) and tigecycline (P=0.006) were observed among non-fragilis Bacteroides spp. isolates than among B. fragilis isolates. Moreover, the susceptibility rates to clindamycin (P=0.003) and tigecycline (P=0.044) decreased significantly among non-fragilis Bacteroides spp. over time. Clindamycin susceptibility rates >80% were found in Greece (100%), Sweden (86.3%) and the UK (80.7%), and the lowest susceptibility rates were found in the USA (42.9%) and Japan (53.9%). In conclusion, the susceptibility of Bacteroides spp. to commonly used antibiotics varied geographically. Empirical antibiotic therapy for suspected anaerobic infections with clindamycin and cefoxitin should be avoided due to high resistance rates. Piperacillin-tazobactam, meropenem, metronidazole and tigecycline could be considered favourable options for the treatment of infections caused by Bacteroides spp.

Topics: Anti-Bacterial Agents; Anti-Infective Agents; Bacteroides fragilis; Bacteroides Infections; Cefoxitin; Clindamycin; Humans; Leadership; Meropenem; Microbial Sensitivity Tests; Piperacillin; Tazobactam; Tigecycline

Bacteroides fluxus is a Gram-negative anaerobic bacillus isolated from human faeces in healthy individuals. Until now, this bacterium had not been involved in human diseases. We report the first case of abdominal infection due to this microorganism in an elderly patient. A 76-year-old man with a history of chronic pulmonary obstructive disease presented with dyspnea, orthopnea and cough. The clinical evolution worsened with both a colonic ischemia and further diffuse peritonitis of pancreatic origin. Peritoneal fluid was obtained and the culture yielded B. fluxus in pure culture. Resistance to penicillin, amoxicillin-clavulanate, clindamycin and moxifloxacin was documented. Treatment with meropenem + linezolid was started, but the patient finally died due to a multiorganic failure.

Topics: Aged; Anti-Bacterial Agents; Bacteroides; Bacteroides Infections; Fatal Outcome; Humans; Intraabdominal Infections; Linezolid; Male; Meropenem; Microbial Sensitivity Tests

Some strains of Bacteroides fragilis species are associated with diarrhea as a result of enterotoxin production (bft or fragilysin). Fragilysin is activated by C11 protease (fpn) and together with C10 protease (bfp) play a significant role in its invasiveness. The objectives of this study were to investigate the proportion of clinical isolates from extra-intestinal sources that are toxin producers and characterize the genes mediating toxin production. Clinical isolates submitted to our reference laboratory over the last 13 years were screened for toxin production using PCR technique. All stool isolates were excluded. The isolates were tested for their susceptibility to 8 antimicrobial agents by E test. Carbapenem resistance gene cfiA was detected by PCR.. A total of 421 B. fragilis isolates were viable. Out of these, bft was detected in 210 (49.9%) isolates. Of the 210 bft-positive isolates, 171 (81.4%), 33 (15.7%) and 6 (2.8%) harbored bft-1, bft-2, and bft-3 genes, respectively. Twenty (9.5%) of the bft-positive strains originated from bloodstream infections. Twenty-five, 20 and 9 strains harbored bfp-1, bfp-2 and bfp-3 gene, respectively. Two, 3, 4 bfp isotypes were detected simultaneously in some of strains. The resistance rates against amoxicillin-clavulanic acid was 32%, clindamycin 62%, cefoxitin 26%, imipenem 11%, meropenem 17%, metronidazole 4%, piperacillin 61% and tigecycline 14%. A chromosomally located cfiA gene that encode metallo-β-lactamase was identified in only 34 isolates (16.2%).. The prevalence of enterotoxin-producing B. fragilis was high among the extra-intestinal isolates. Metronidazole was the most active agent against all isolates. There was no statistically significance difference between resistance rates among bft-positive and bft-negative isolates except for clindamycin.

Topics: Amoxicillin-Potassium Clavulanate Combination; Anti-Bacterial Agents; Bacterial Toxins; Bacteroides fragilis; Bacteroides Infections; Cefoxitin; Clindamycin; Drug Resistance, Bacterial; Feces; Female; Humans; Imipenem; Kuwait; Male; Meropenem; Metronidazole; Microbial Sensitivity Tests; Piperacillin; Prevalence; Prospective Studies; Respiratory Tract Infections; Sepsis; Tigecycline; Wound Infection

The in vitro susceptibilities of Bacteroides fragilis to antimicrobial agents, especially to carbapenem, are a major concern in the treatment of patients with bloodstream infections. In this study, 50 isolates of B. fragilis were obtained from positive blood bottles from 2014 to 2019 in Saitama, Japan. Their susceptibility to ampicillin/sulbactam was reduced to 70.0% compared with a previous report, whereas they were still sufficiently susceptible to piperacillin/tazobactam (94.0%). Five cfiA-positive isolates (5/50, 10.0%) were identified that were resistant to doripenem and meropenem, and two of them carried an insertion sequence located upstream of the cfiA-coding region. In particular, imipenem should be considered as a first-line carbapenem for the empirical treatment of B. fragilis infection because only insertion sequence and cfiA double-positive strains showed resistance to imipenem. Thirty-six percent of the isolates had a reduced minimum inhibitory concentration for moxifloxacin. In addition, metronidazole should still be considered as an active agent for B. fragilis because all isolates were susceptible to this antibiotic and the prevalence of the nim gene was low in Japan.

Topics: Ampicillin; Anti-Bacterial Agents; Bacterial Proteins; Bacteroides fragilis; Bacteroides Infections; beta-Lactamases; Blood Culture; DNA Transposable Elements; Doripenem; Drug Resistance, Multiple, Bacterial; Genes, Bacterial; Humans; Imipenem; Japan; Meropenem; Metronidazole; Microbial Sensitivity Tests; Moxifloxacin; Piperacillin, Tazobactam Drug Combination; Prevalence; Sulbactam; Tertiary Care Centers

The Bacteroides fragilis group constitute a significant portion of the human gut microbiota and comprise a major proportion of anaerobic bacteria isolated in human infections. We established a baseline of antimicrobial susceptibility rates in the B. fragilis group in the intestinal tract of relatively antibiotic-naive healthy Danish children. From 174 faecal samples collected from children attending day care, 359 non-duplicate isolates were screened for antimicrobial susceptibility. Of these, 0.0%, 1.9%, 5.0% and 21.2% of isolates were intermediate-susceptible or resistant to metronidazole, meropenem, piperacillin/tazobactam and clindamycin, respectively. Eighteen additional studies reporting susceptibility rates in the B. fragilis group bacteria were identified by conducting a literature search. Heterogeneity among results from studies of B. fragilis group antimicrobial susceptibility rates in faecal microbiota exists.

Topics: Anti-Bacterial Agents; Bacteroides fragilis; Bacteroides Infections; Child; Clindamycin; Denmark; Drug Resistance, Bacterial; Feces; Humans; Meropenem; Metronidazole; Microbial Sensitivity Tests; Microbiota; Penicillanic Acid; Piperacillin; Piperacillin, Tazobactam Drug Combination; Surveys and Questionnaires; Thienamycins

Periodic monitoring of antimicrobial resistance trends of clinically important anaerobic bacteria such as Bacteroides fragilis group organisms is required. We determined the antimicrobial susceptibilities of clinical isolates of B. fragilis group organisms recovered from 2009 to 2012 in a tertiary-care hospital in Korea.. A total of 180 nonduplicate clinical isolates of B. fragilis group organisms were collected in a tertiary care hospital. The species were identified by conventional methods: the ATB 32A rapid identification system (bioMérieux, France) and the Vitek MS matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (bioMérieux). Antimicrobial susceptibility was determined by the CLSI agar dilution method.. Imipenem and meropenem resistance rates were 0-6% for B. fragilis group isolates. The rate of resistance to piperacillin-tazobactam was 2% for B. fragilis and 0% for other Bacteroides species, but 17% for B. thetaiotaomicron isolates. High resistance rates to piperacillin (72% and 69%), cefotetan (89% and 58%), and clindamycin (83% and 69%) were observed for B. thetaiotaomicron and other Bacteroides spp. The moxifloxacin resistance rate was 27% for other Bacteroides spp. The MIC50 and MIC90 of tigecycline were 2-4 µg/mL and 8-16 µg/mL, respectively. No isolates were resistant to chloramphenicol or metronidazole.. Imipenem, meropenem, chloramphenicol, and metronidazole remain active against B. fragilis group isolates. Moxifloxacin and tigecycline resistance rates are 2-27% and 8-15% for B. fragilis group isolates, respectively.

Topics: Anti-Infective Agents; Bacteroides fragilis; Bacteroides Infections; Drug Resistance, Multiple, Bacterial; Humans; Imipenem; Inhibitory Concentration 50; Meropenem; Microbial Sensitivity Tests; Penicillanic Acid; Piperacillin; Republic of Korea; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tazobactam; Tertiary Care Centers; Thienamycins

Bacteroides fragilis, which is found in normal colon flora, is the most commonly encountered pathogen in anaerobic infections and more resistant to antimicrobial agents than the other anaerobes. Limited number of antibiotics; such as carbapenems, beta-lactam/beta-lactamase inhibitors and nitroimidazoles are the most effective antibiotics against Bacteroides, however resistant isolates to these antimicrobials have been reported recently. Resistance against carbapenems occurs due to a metallo-beta-lactamase enzyme expressed by cfiA gene. While agar dilution method is used to test the antimicrobial susceptibility of anaerobic organisms, E-test is recommended for susceptibility testing of anaerobes associated with life-threatening infections with high mortality and morbidity. In this study, meropenem E-test was used to determine the carbapenem resistance of B.fragilis strains and to estimate the presence of cfiA gene. A total of 63 B.fragilis strains that were previously isolated from clinical samples (of which 16 were from stool samples) in our laboratory, were enrolled in the study. Minimum inhibitory concentration (MIC) values were determined by meropenem E test (AB Biodisk, Sweden) and presence of cfiA genes were investigated by in-house polymerase chain reaction. The MIC ranges of meropenem were < 0.002 - > 32 µg/ml and the resistance rate was 9.5% (6/63). Thirty-three percent (21/63) of strains harboured cfiA gene. A statistically significant relation (p< 0.0001) was determined between presence of cfiA gene and high MIC value (MIC 0.5 µg/ml). The proportion of cfiA-positive isolates detected in this study was substantially higher than that reported in other countries. This might be attributed to the frequent use of carbapenems in our hospital. The results of this study indicated that meropenem E-test method could be useful to estimate the presence of cfiA gene in B.fragilis strains and thus to detect the resistant strains.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Bacteroides fragilis; Bacteroides Infections; beta-Lactamases; Carbapenems; Drug Resistance, Bacterial; Feces; Humans; Imipenem; Meropenem; Metalloproteins; Microbial Sensitivity Tests; Thienamycins; Turkey

This study reports data on the susceptibilities to five commonly used antianaerobic agents of five clinically frequently encountered anaerobes from 2000 to 2007 and to Bacteroides fragilis isolates causing nosocomial infections from 1990 to 2006. There was a trend of decreasing susceptibilities of these anaerobes to ampicillin-sulbactam, cefmetazole, chloramphenicol, and clindamycin with time during the study period. The rates of susceptibility to clindamycin and cefmetazole for all clinical isolates of Bacteroides fragilis isolates were higher than those of isolates associated with nosocomial infections. The MICs of 207 anaerobic blood isolates collected in 2006 to 14 antimicrobial agents were determined by the agar dilution method. The rates of nonsusceptibility to imipenem and meropenem were 7% and 12% for B. fragilis isolates (n = 60), 7% and 3% for Bacteroides thetaiotamicron isolates (n = 30), 4% and 4% for Fusobacterium species (n = 27), 6% and 0% for Prevotella species (n = 16), 15% and 0% for Clostridium species (n = 28), and 0% and 0% for Peptostreptococcus species (n = 32). The rates of susceptibility to moxifloxacin were 90% for B. fragilis isolates, 87% for B. thetaiotaomicron isolates, 81% for Fusobacterium species, 75% for Prevotella species, 93% for Clostridium species, and 78% for Peptostreptococcus species. Thirty-six percent of Clostridium species and 12% of Peptostreptococcus species were not susceptible to metronidazole. Comparison of the data with the data from a previous survey from the same institute in 2002 revealed higher rates of nonsusceptibility to carbapenems, especially for B. fragilis, Fusobacterium species, and Prevotella species isolates. The high rates of nonsusceptibility to commonly used antianaerobic agents mandate our attention, and periodic monitoring of the trend of the resistance is crucial.

Topics: Anti-Bacterial Agents; Bacteria, Anaerobic; Bacteroides fragilis; Bacteroides Infections; Blood; Carbapenems; Cross Infection; Drug Resistance, Bacterial; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Microbial Sensitivity Tests; Taiwan

Thirty-five Bacteroides fragilis clinical isolates with varying susceptibility to meropenem were analysed with a prototype of a double-ended Etest strip containing meropenem +/- EDTA, designed for the detection of the CfiA metallo-beta-lactamase. Phenotypic results obtained with this new Etest strip were related to the genotype and compared to the results of the Etest containing imipenem +/- EDTA. Whereas the Etest with imipenem +/- EDTA only allowed detection of isolates with high-level resistance (both MICs of imipenem and meropenem >32 mg/L), reflecting the possible underestimation of CfiA prevalence in B. fragilis, the Etest with meropenem +/- EDTA proved to be more accurate, particularly for isolates with low-level carbapenem resistance, suggesting its potential for broader detection of CfiA production.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Bacteroides fragilis; Bacteroides Infections; beta-Lactam Resistance; beta-Lactamases; DNA, Bacterial; Genes, Bacterial; Genotype; Humans; Meropenem; Microbial Sensitivity Tests; Thienamycins

Of 1284 Bacteroides strains collected in Europe in 2000 for antibiotic susceptibility surveillance, 65 isolates displayed imipenem minimum inhibitory concentrations (MICs) > or =1 mg/L and were chosen for a thorough analysis of their resistance mechanism. Twenty-five of the isolates were positive for the cfiA carbapenem resistance gene. The resistance rates were 0.8% and 1.3% for imipenem and meropenem, respectively. In six of the strains, insertion sequence (IS) elements (IS613, IS614B, IS1186 and IS1187) activated the cfiA gene. However, other strains displayed at least elevated carbapenem MICs or were carbapenem resistant and produced measurable carbapenemase activities but did not harbour IS elements in the region upstream of the cfiA gene. The major determinant of carbapenem resistance in Bacteroides fragilis is production of CfiA metallo-beta-lactamase via activation of the cfiA gene by IS elements (higher level resistance) or by activation of its putative own promoter.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Bacteroides fragilis; Bacteroides Infections; Base Sequence; beta-Lactamases; Carbapenems; DNA Transposable Elements; Drug Resistance, Bacterial; Europe; Humans; Imipenem; Meropenem; Microbial Sensitivity Tests; Molecular Sequence Data; Polymerase Chain Reaction; Population Surveillance; Thienamycins

In 2003 a Bacteroides fragilis blood culture isolate (K2-28) was recovered from a 61-y-old male with severe general atherosclerosis during treatment with meropenem. K2-28 was shown to possess a functional metallo-beta-lactamase with a reduction in imipenem MIC from 256 to 3 mg/l in the presence of EDTA using the MBL E-test strip. PCR results were for positive for the cfiA gene. Analysis of the cfiA from K2-28 revealed it was 100% identical to previously described cfiA-1 genes. Analysis of the upstream region of cfiA revealed a novel insertion sequence (IS) element, being most similar (94% identity) to IS612 recently described from Japan designating the element within the IS4 family. The element possessed a perfect terminal inverted repeat sequence at the distal ends of the IS element and provided a putative promoter for transcription of the cfiA gene. The distance between the hybrid promoter and the cfiA start codon was 158 base pairs and inserted into a different DNA sequence upstream of cfiA to that previously reported. The -10 promoter region was most similar to that of IS613 (100%) and the -35 promoter region to IS612 (100%), demonstrating the plasticity of these genetic regions.

Topics: Bacterial Proteins; Bacteroides fragilis; Bacteroides Infections; Base Sequence; beta-Lactam Resistance; beta-Lactamases; DNA Transposable Elements; Gene Expression Regulation, Bacterial; Humans; Imipenem; Male; Meropenem; Microbial Sensitivity Tests; Middle Aged; Molecular Sequence Data; Norway; Polymerase Chain Reaction; Promoter Regions, Genetic; Repetitive Sequences, Nucleic Acid; Sequence Analysis, DNA; Thienamycins

The carbapenemase gene (cfiA) was detected in 4 (5.7%) of 70 clinical isolates of Bacteroides fragilis from different parts of Hungary. Among 24 other Bacteroides species isolated from infectious processes or from normal faecal flora, none was cfiA-positive. The MIC of imipenem and meropenem for all cfiA-positive B. fragilis isolates was < or =0.25 mg/L, but 17% of the B. fragilis and 46% of the non-fragilis Bacteroides isolates exhibited reduced susceptibility to imipenem (MICs 0.5-2 mg/L). Only one of these isolates produced increased levels of beta-lactamase. No difference was observed in the outer-membrane proteins of B. fragilis isolates that harboured the cfiA gene and those with reduced susceptibility to imipenem.

Topics: Bacterial Proteins; Bacteroides; Bacteroides Infections; beta-Lactamases; Blotting, Southern; Humans; Hungary; Imipenem; Meropenem; Metalloproteins; Microbial Sensitivity Tests; Polymerase Chain Reaction; Prevalence; Thienamycins