Neonatal sepsis bacterial isolates and antibiotic susceptibility patterns at a NICU in a tertiary care hospital in western Nepal: a retrospective analysis.

BACKGROUND: Neonatal sepsis is one of the commonest causes of neonatal mortality in the developing world. The neonatal intensive care units (NICUs) today face one common problem of tackling sepsis and neonatologists remain constantly baffled by the changing patterns of microbial flora and their sensitivity patterns. With the neonatal services coming of age in Nepal this retrospective analysis spread over a period of six years has become very pertinent.
MATERIALS AND METHODS: We conducted a retrospective study over a period of six years to study the prevalence of different organisms causing septicaemia in the community and at our hospital and the antibiotic susceptibility pattern. In all 265 cases of suspected sepsis were screened using a panel consisting of CRP, ANC and I/T ratio and subsequently confirmed by cultures. The cases were early onset (n=44), late onset (n=56) and nosocomial groups (n=40). The data for the intramural (n=32) and extramural (n=68) cases was analysed separately.
RESULTS: One hundred nineteen cultures out of the 131 positives were obtained from blood (44.92%) and the remaining were isolated from urine (6.11 %) and CSF (4.58 %). The most common organism to be isolated was staphylococcus aureus (42.75%) followed by klebsiella pneumoniae (18.32%)and escherechia coli (12.21%). Staphylococcus was isolated from 36.84%, 45.16% and 31.81% of the cultures obtained from neonates in the in-born, out-born and the nosocomial groups respectively while klebsiella pneumoniae [18.32 %] was seen in 21.05 %, 17.39 % and 36.36 % in each of the three groups. Pseudomonas aeruginosa [6.11 %] was isolated from 13.64 % of the nosocomial cultures compared to 8.7 % of the out-borns while it was not seen in the in-borns. Other organisms isolated were much less in number, included - pathogenic streptococci, acinetobacter and enterobacter species. Coagulase negative staphylococci (CoNS) was seen in 4.39 % [n=4] and 9.09 % [n=4] of the same groups respectively. The gram positive organisms displayed a high degree of resistance to most penicillins and cephalosporins but glycopeptides and monobactams were effective in them. There was a high incidence of resistance noted with most third generation cephalosporins and aminoglycosides amongst most gram negative organisms where-in cefepime and imepenem were effective in most cases.
CONCLUSIONS: Staphylococcal sepsis is not only common in community acquired infections but also in nosocomial sepsis. There is an emerging resistance to cephalosposrins probably attributable to extended spectrum betalactamases. Further large-scale multicentre studies are required to generalise the data for the whole country.