Association of biofilm production with multidrug resistance among clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa from intensive care unit.

BACKGROUND AND AIMS: Given choice, bacteria prefer a community-based, surface-bound colony to an individual existence. The inclination for bacteria to become surface bound is so ubiquitous in diverse ecosystems that it suggests a strong survival strategy and selective advantage for surface dwellers over their free-ranging counterparts. Virtually any surface, biotic or abiotic (animal, mineral, or vegetable) is suitable for bacterial colonization and biofilm formation. Thus, a biofilm is "a functional consortium of microorganisms organized within an extensive exopolymeric matrix." MATERIALS AND METHODS: The present study was undertaken to detect biofilm production from the repertoire stocks of Acinetobacter baumannii (A. baumannii) and Pseudomonas aeruginosa (P. aeruginosa) obtained from clinical specimens. The tube method was performed to qualitatively detect biofilm production. RESULTS: A total of 109 isolates of both organisms were included in the study, out of which 42% (46/109) isolates showed biofilm detection. Among the biofilm producers, 57% of P. aeruginosa and 73% of A. baumannii showed multidrug resistance (MDR) pattern which was statistically significant in comparison to nonbiofilm producers (P < 0.001). CONCLUSION: To the best of our knowledge, this is the only study to have tested the biofilm production in both P. aeruginosa and A. baumannii in a single study. Biofilm production and MDR pattern were found to be significantly higher in A. baumannii than P. aeruginosa. Antibiotic resistance was significantly higher among biofilm producing P. aeruginosa than non producers. Similarly, antibiotic resistance was significantly higher among biofilm producing A. baumannii than non producers.

Presence of Resistant DEC Strains in a Tertiary Healthcare Center in North East India in Children under 18 Years.

Introduction Diarrheal illness such as diarrheagenic Escherichia coli (DEC), apart from rotavirus, is a common etiological agent known to cause moderate-to-severe diarrhea in low-income countries where unregulated use of antibiotics is rampant, giving rise to multidrug resistant (MDR) strains. This study is an earnest effort in reflecting the resistance pattern in such isolates. Materials and Methods It is a hospital-based cross-sectional study conducted over a period of 1 year (January to December, 2015). Children aged less than 18 years presenting with ( n = 170) and without ( n = 47) diarrhea were included as cases and controls, respectively. Fresh stool sample from eligible participants was collected and inoculated on MacConkey agar. Based on the colony morphology and biochemical identification followed by polymerase chain reaction (PCR), different pathotypes of DEC were identified. All such isolates were subjected to antimicrobial susceptibility testing employing VITEK 2 identification system. The result of the tested antibiotics was evaluated as per Clinical and Laboratory Standards Institute 2015 guidelines. Results DEC with specific virulence genes were detected by multiplex real-time PCR in 39 and 3 children with or without diarrhea, respectively. Most common DEC pathotypes found were enteroaggregative E. coli (38%) followed by enteropathogenic E. coli (28.5%). MDR isolates comprised 35 of 42 DEC pathotypes (83.3%). Resistance among DEC pathotypes to ampicillin, amoxicillin-clavulanate, ciprofloxacin, cephalosporin, nalidixic acid, imipenem, and cotrimoxazole was found to be statistically significant in comparison to non-DEC isolates. Conclusion This study has highlighted the increased prevalence of MDR strains among DEC pathotypes. Looking for these isolates will help detect dreadful DEC pathotypes like enterohemorrhagic E. coli where early administration of a sensitive antibiotic will go a long way in preventing complication like hemorrhagic colitis and hemolytic uremic syndrome.

Real-time multiplex polymerase chain reaction with high-resolution melting-curve analysis for the diagnosis of enteric infections associated with diarrheagenic Escherichia coli.

INTRODUCTION: Although diarrheagenic Escherichia coli (DEC) strains are important bacterial causative agents of diarrhoea, they are not routinely sought as stool pathogens in clinical laboratories as conventional microbiological testing are unable to distinguish between normal flora and pathogenic strains of E. coli. This study was undertaken to determine the prevalence of DEC pathotypes amongst children with and without diarrhoea and to detect specific virulent genes present in different DEC pathotypes, using real-time multiplex polymerase chain reaction (PCR) with high-resolution melting (HRM) technology. MATERIALS AND METHODS: Stool samples were obtained from cases and controls. Using a set of conventional biochemical tests, E. coli strains were identified. Further, these isolates were subjected to multiplex PCR system for the detection of virulence genes of different pathotypes of DEC. Real-time multiplex PCR was performed for the detection of specific virulent genes of DEC pathotypes, using Rotor-Gene Q instrument (Qiagen) having High-resolution Melt analyser using Type-it HRM PCR kit (Qiagen) containing EvaGreen fluorescent intercalating dye. RESULTS: In this study, we had successfully standardised two multiplex PCR assays which were found to be effective for direct detection of enteropathogenic E. coli (EPEC), enteroaggregative E. coli (EAEC), enterotoxigenic E. coli (ETEC) and enteroinvasive E. coli (EIEC). A total of 42 DEC strains were detected at an overall rate of 19.3% (n = 42), from the total 217 E. coli isolates recovered from the cases (n = 39, 17.9%) and control (n = 3, 3.8%) groups. Amongst the 42 DEC pathotypes (39 from cases and 3 from controls), EPEC (10%), EAEC (8.82%), ETEC (2.94%) and EIEC (1.18%) were found in children with diarrhoea (cases) and in children without diarrhoea (control) only EAEC (2.13%) and EPEC (4.26%) were detected. Age distribution, gender variation, seasonal variation and clinical features were also analysed. CONCLUSION: This study helped evaluate the prevalence of DEC amongst children (<18 years of age) with and without diarrhoea using multiplex real-time PCR with HRM analysis.

Sub-cutaneous abscess caused by Nocardia asteroides in renal transplant recipient.

Nocardia is a significant opportunistic pathogen in patients with compromised immunity. Nocardia asteroides was isolated from subcutaneous abscesses on the left thigh and shoulder of a renal transplant recipient. Direct examination of the aspirated pus showed branching filaments that were gram-positive and acid fast. The abscesses were drained and the patient responded to high dose co-trimoxazole therapy.