RESUMO
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.
RESUMO
AIMS: Methicillin-resistant Staphylococcus aureus (MRSA) has become a serious problem in intensive care units, because of development of multiresistance, and also intrinsic resistance to beta-lactam antibiotics. The present study was carried out to investigate the prevalence of MRSA and their rate of resistance to different antistaphylococcal antibiotics. MATERIALS AND METHODS: Between January 2007 and February 2008, the clinical specimens submitted at the microbiology laboratory were processed and all S. aureus isolates were included in this study. All isolates were identified morphologically and biochemically by standard laboratory procedures and antibiotic susceptibility pattern was determined by modified Kirby Bauer disc diffusion method. RESULTS: Methicillin resistance was observed in 34.78% of isolates, of which 37.5% were found to be resistant to all commonly used antibiotics. In MRSA isolates, 50% had constitutive resistance, 9.38% had inducible MLS(B) resistance and 18.75% had MS phenotype. CONCLUSIONS: There is a progressive increase in MRSA prevalence in the country but the present rate is still low in comparison to values found in some other institutes. The rate of inducible MLS(B) resistance was also lower in comparison with findings from other parts of the country.