ABSTRACT
Background & objectives: Information about the genetic diversity of the extended-spectrum β-lactamases (ESBLs) and the clonal relationship of the organisms causing neonatal infections is limited, particularly from India where neonatal mortality is high. This study was undertaken to investigate the molecular epidemiology and risk factors associated with neonatal septicaemia caused by ESBL-producing Klebsiella pneumoniae and Escherichia coli. Methods: Bloodstream isolates (n=26) of K. pneumoniae (n=10) and E. coli (n=16) from the neonates admitted in a tertiary care hospital in New Delhi during January to May 2008 were characterized. Antimicrobial susceptibility tests were carried out and ESBL production was assessed phenotypically. PCR was carried out for ESBL and ampC genes. Genotyping was performed by pulsed-field gel electrophoresis (PFGE). Conjugation experiments were done to determine the mobility of ESBL genes. Risk factors associated with ESBL-producing K. pneumoniae and E. coli infections were analysed. Results: Resistance rates to most of the antibiotics tested were high, except for imipenem. Among the isolates tested, 60 per cent of K. pneumoniae and 75 per cent of E. coli were ESBL producers. PFGE of the isolates demonstrated a vast diversity of genotypes with no epidemic clones. Despite the clonal diversity, blaCTX-M-15 was detected in 100 per cent of ESBL-positive isolates. The other genes present in ESBL-positive isolates were blaTEM-1, blaSHV-1, blaSHV-28, blaSHV-11, and blaSHV-12. Class 1 integrons were detected in 7 of 18 ESBL-positive isolates. Moreover, the plasmid carrying blaCTX-M-15, in E. coli and K. pneumoniae were self transferable. Feeding through an enteral tube was identified as the only risk factor for sepsis by ESBL-producing organisms. Interpretation & conclusions: The study emphasises the presence of blaCTX-M-15 in clonally diverse isolates indicating probable horizontal transfer of this gene. The widespread dissemination of CTX-M-15 is of great concern as it further confines the limited therapeutic interventions available for neonates.
ABSTRACT
Although sepsis is a major cause of morbidity and mortality among newborns in resource-poor countries, little data are available from rural areas on culture-proven sepsis. The aim of the present study was to provide information in this regard. The study reports results on the incidence and aetiology of neonatal sepsis cases admitted to a facility in a rural area in eastern India. Blood culture was done for all babies, with suspected clinical sepsis, who were admitted to the sick newborn care unit at Suri where the study was conducted during March 2009–August 2010. A standard form was used for collecting clinical and demographic data. In total, 216 neonatal blood culture samples were processed, of which 100 (46.3%) grew potential pathogens. Gram-negative infection was predominant (58/100 cases) mainly caused by enteric Gram-negative bacteria. Klebsiella pneumoniae was the most common Gram-negative isolate. The emergence of fungal infection was observed, with 40% of the infection caused by yeast. Gram-negative organisms exhibited 100% resistance to ampicillin, cefotaxime, and gentamicin. Amikacin and co-trimoxazole showed 95% (n=57) resistance, and ciprofloxacin showed 83.3% (n=50) resistance among the Gram-negative bacteria. Carbapenem showed emerging resistance (n=4; 6.6%). Results of analysis of risk factors showed an extremely significant association between gestation and sepsis and gender and sepsis. Gastrointestinal symptoms were highly specific for fungal infections. One-third of babies (n=29), who developed culture-positive sepsis, died. Blood culture is an investigation which is frequently unavailable in rural India. As a result, empirical antibiotic therapy is commonly used. The present study attempted to provide data for evidence-based antibiotic therapy given to sick newborns in such rural units. The results suggest that there is a high rate of antibiotic resistance in rural India. Urgent steps need to be taken to combat this resistance.