Neonatal sepsis: high antibiotic resistance of the bacterial pathogens in a neonatal intensive care unit in Karachi.

OBJECTIVE

To study the bacterial pathogens causing neonatal sepsis and their sensitivity pattern so that guidelines can be prepared for empirical antibiotic therapy.

SETTING

The study was conducted in the neonatal intensive care unit (NICU) at PNS Shifa (Naval Hospital), Karachi during January 1997 to June 1999.

METHODS

Blood specimens for culture were drawn from 520 newborns admitted in a NICU with sepsis. The specimens were inoculated into brain heart infusion broth. Subcultures were performed on days 1, 2, 3, 5, 7 and 10. The isolates were identified by standard biochemical tests. Antibiotic resistance pattern of the isolates was studied by Modified Kirby Baur disc diffusion technique.

RESULTS

A total of 212 organisms were isolated. These included Staphylococcus aureus (n = 65), Klebsiella pneumoniae (n = 73), Acinetobacter baumannii (n = 23), Escherichia coli (n = 22), Enterobacter cloacae (n = 18), Citrobacter diversus (n = 5), Pseudomonas aeruginosa (n = 4) and group B Streptococcus (n = 2). On antibiotic sensitivity testing, 61.54% of Staphylococcus aureus isolates were found to be methicillin resistant. Susceptibility to the other common drugs was also quite low while 89.23% of these were susceptible to amikacin and 100% to vancomycin. More than 90% gram negative rods were resistant to ampicillin and co-trimoxazole. Resistance to gentamicin was as high as 90.4% for Klebsiella pneumoniae; 60.87% for Acinetobacter baumannii. Resistance to the third generation cephalosporins and the quinolone tested (ciprofloxacin) varied between 25-75%. Majority of the isolates were susceptible to meropenem and amikacin.

CONCLUSION

In view of the isolation of highly antibiotic resistant organisms, vancomycin in combination with amikacin or a carbapenem is the drug of choice for empirically treating neonatal sepsis.