ABSTRACT
Background & objectives: Vancomycin-resistant enterococci (VRE) have become one of the most challenging nosocomial pathogens with the rapid spread of the multi-drug resistant strain with limited therapeutic options. It is a matter of concern due to its ability to transfer vancomycin resistant gene to other organisms. The present study was undertaken to determine the emergence of vancomycin-resistant enterococci and the vanA gene among the isolates in a tertiary care hospital of North-East India. Methods: A total of 67 consecutive enterococcal isolates from different clinical samples were collected and identified by using the standard methods. Antibiogram was done by disk diffusion method and VRE was screened by the disk diffusion and vancomycin supplement agar dilution method. The minimum inhibitory concentration (MIC) value for vancomycin was determined by E-test. The VRE isolates were analyzed by PCR for vanA gene. Results: A total of 54 (81%) Enterococcus faecalis and 13 (19%) E. faecium were detected among the clinical isolates and 16 (24%) were VRE. The VRE isolates were multidrug resistant and linezolid resistance was also found to be in three. MIC range to vancomycin was 16-32 μg/ml among the VRE. The vanA gene was found in nine of 16 VRE isolates. Interpretation & conclusions: Emergence of VRE and presence of vanA in a tertiary care hospital setting in North-East India indicate toward a need for implementing infection control policies and active surveillance.
ABSTRACT
Extended-spectrum β-lactamases (ESBLs) are rapidly evolving group of β-lactamase enzymes produced by the Gram negative bacteria. In this study, we determined the antimicrobial sensitivity pattern of Escherichia coli isolates and prevalence of TEM, SHV and CTX-M genes in ESBL positive E. coli isolated from the patients admitted to a tertiary care hospital in North-East India. A total of 85 multidrug-resistant isolates of E. coli obtained from clinical samples; urine (n=80), sputum (n=3), body fluid (n=1), vaginal discharge (n=1) were screened for resistance to third generation cephalosporins. ESBL production in resistant isolates was determined by double disk synergy test (DDST) and phenotypic confirmatory test (PCT). ESBL positive isolates were subjected to PCR for detection of TEM, SHV and CTX-M genes. Imipenem was found to be most effective against E. coli (susceptible isolates 96.47%) while ciprofloxacin was the least effective antibiotic (resistant isolates 60%). Among 33 ESBL positive isolates confirmed via PCT, preponderance in female population (60.6%) was noted. The most prevalent gene was blaSHV (63.04%) followed by blaTEM and blaCTX-M (60.86 and 54.34%, respectively) in ESBL positive E. coli. Most of the extensively used antibiotics, appear to be ineffective against the ever-mutating bacteria. This resistance urges cautious antimicrobial management on priority. Further, it helps in effectively designing the chemotherapeutic regimen for patients of a particular geographic area.
ABSTRACT
Background & objectives: Haemophilus influenzae is an important cause of mortality and morbidity among young children in developing countries. Increasing incidence of antibiotic resistance especially production of extended spectrum beta lactamase (ESBL) has made treatment and management of H. influenzae infection more difficult. Nasopharyngeal H. influenzae isolates are excellent surrogate for determination of antibiotic resistance prevalent among invasive H. influenzae isolates. In this study, we characterized nasopharyngeal H. influenzae isolates obtained from healthy school going children in Delhi. Methods: Nasopharyngeal H. influenzae isolates were collected from healthy school going children and subjected to serotyping, fimbrial typing and antibiogram profiling. ESBL production was recorded using phenotypic as well as molecular methods. Multi locus sequence typing (MLST) of 13 representative nasopharyngeal H. influenzae isolates was performed as per guidelines. Results: A significant proportion (26 of 80, 32.5%) of nasopharyngeal isolates of H. influenzae were identified as serotype b. Fimbrial gene (hifA) was detected in 23 (28.75%) isolates. Resistance against commonly prescribed antibiotics (Amp, Tet, Chloro, Septran, Cephalexin) were observed to be high among the nasopharyngeal commensal H. influenzae. Extended spectrum beta lactamase (ESBL) production was observed in a five (6.25%) isolates by both double disk diffusion and molecular typing. MLST identified several novel alleles as well as novel sequence types. Interpretation & conclusions: Our findings showed high resistance against common antibiotics and detection of ESBL in nasopharyngeal H. influenzae isolates collected from normal healthy school going children in Delhi. Detection of H. influenzae type b capsular gene and the presence of fimbrial gene (hif A) suggest virulence potential of these isolates. Discovery of novel alleles and presence of new sequence types (STs) among nasopharyngeal H. influenzae isolates may suggest wider genetic diversity.