Bacterial Contamination of Surfaces and Equipment and Antimicrobial Susceptibility Pattern of Potentially Pathogenic Bacteria in Newborn Unit at Kenyatta National Hospital

Abstract

BACKGROUND Nosocomial infections in newborn units pose a great challenge to health care systems. They have been linked to contaminated surfaces and equipment in neonatal wards. The sources and spread of the infections are mainly attributed to contamination of fomites within the hospital environment. OBJECTIVE To investigate the bacterial contamination profile of surfaces and equipment in the newborn unit (NBU) of Kenyatta National Hospital (KNH) and determine the antimicrobial susceptibility pattern of selected potentially pathogenic bacteria, which include E. coli, S. aureus, Coagulase-negative staphylococci (CoNS), K. pneumoniae, and P. aeruginosa. METHODS A cross-sectional study was conducted in the NBU of KNH. Samples from surfaces and equipment were systematically collected from NBU until the required sample size was obtained. All the steps of sample collection and inoculation were carried out using aseptic techniques and transported to the Microbiology Laboratory of the University of Nairobi (UON) within 1- 2 hours of collection for analysis. Samples were cultured on selective and non-selective media. Phenotypic identification of the isolates was based on colonial morphology, gram staining, and biochemical tests. Antimicrobial susceptibility testing for selected bacteria was determined using the Kirby-Bauer disk method. Univariate and bivariate analyses were done using IBM® SPSS® software version 21.0 and data were presented in tables and graphs. RESULTS A total of 580 swabs were collected from surfaces and equipment in six different NBU locations/rooms. Following inoculation on the culture plates, 273 (54%) swabs showed growth. The majority of the positive bacterial cultures, 137/273 (50.2%), were coagulasenegative staphylococcus (CoNS). Others were: Klebsiella pneumoniae, 119/273 (43.6%); Escherichia coli 16/273 (5.9%), and Pseudomonas aeruginosa 1/273 (0.4%). Equipment and xi surfaces with abundant growth included cots 55/273 (20%), radiant warmers 51/273 (19%), oxygen masks 46/273 (17%), incubators 16/273 (6%), desk surfaces 29/273 (11%), sinks 24/273 (9%), door handles 17/273 (6%) and taps 16/273 (6%). Most of the isolates were highly susceptible to meropenem, amikacin, and imipenem (70-100%) but resistant to penicillin, clindamycin, and vancomycin (45-100%). CONCLUSION AND RECOMMENDATIONS The study determined that newborn environmental surfaces and equipment at the Kenyatta National Hospital were contaminated with potentially pathogenic bacteria including CoNS, K. pneumoniae, and E. coli. The majority of the isolated bacteria were sensitive to meropenem, imipenem, and amikacin. All bacteria isolated had high resistance to penicillin, vancomycin, and clindamycin. The identified potentially pathogenic bacteria isolated from the NBU could be the source of infections to preterm and sick term neonate infants. Therefore, this study recommends improved compliance with infection control practices (hand hygiene, sterilization, and disinfection of patient-care items, devices, and environmental infection prevention and control) in the NBU at KNH.