Isolation and Identification of Biofilm-Producing, Drug-Resistant Coagulase Negative Staphylococci from a Hospital Environment in Northern Philippines

Allan Jay C Espiritu,Sharon Yvette Angelina M Villanueva

doi:10.22207/jpam.16.1.63

Abstract

Healthcare-associated infections (HCAIs) are considered adverse outcomes of confinement in a healthcare facility. Biofilm-producing, drug-resistant bacteria have further aggravated the problem with HCAIs. This study determined the prevalence, antibiotic susceptibility, and biofilm phenotype of coagulase-negative staphylococci (CoNS) isolated from a hospital environment in Northern Philippines. The identification of CoNS species and the determination of antibiotic susceptibility were done using an automated assay. Biofilm production was detected using tissue culture plate (TCP) and Congo red agar (CRA) methods. Out of 220 surfaces and 26 air samples collected, 103 (41.9%) CoNS strains were isolated, predominated by S. epidermidis with 30.1% prevalence. The medical ward was found to have the highest prevalence of CoNS at 64%. The CoNS isolates exhibited a variable resistance profile; the highest was found against penicillin (97.1%) and oxacillin (54.3%). Isolates manifesting resistance to linezolid and vancomycin were also detected. From the 103 CoNS isolates, 52 (50.5%) biofilm producers were detected using the TCP method, and 39 (37.9%) were detected by the CRA method. Statistically significant difference was found between the biofilm biomass and the slime-producing pattern. This study revealed the prevalence of biofilm-producing, drug-resistant strains of CoNS in a Level 3 hospital in Northern Philippines. This warrants further enhancement of infection prevention and control programs to avert the emergence of more biofilm-producing, drug-resistant bacterial strains that could pose formidable threats to public health.

Highlights

The increase in the number of cases of healthcare-associated infections (HCAIs) has been considered as an imminent threat to public health worldwide.[1]
Isolates were subjected to antibiotic susceptibility testing using 15 antibiotics recommended for testing and reporting stated in the Clinical and Laboratory Standards Institute (CLSI) guidelines.[22]
The isolates were highly susceptible to vancomycin (98.1%), linezolid (97.1%), daptomycin (96.1%), chloramphenicol (93.2%), moxifloxacin (92.2%), levofloxacin (91.3%), rifampin (91.3%), trimethoprim-sulfamethoxazole (88.3%), gentamicin and ciprofloxacin (87.4%), and tetracycline (82.6%)

Summary

Introduction

The increase in the number of cases of healthcare-associated infections (HCAIs) has been considered as an imminent threat to public health worldwide.[1]. Bacterial biofilms consist of bacteria that live together in clusters that produce an extracellular polymeric substance (EPS) serving as a protective coat.[5,6] The EPS imparts the protective function against antimicrobials and the host’s immune system while enhancing bacterial pathogenicity through synergism.[7,8] Bacterial biofilms have been found to form on different hospital surfaces and medical devices and are believed to have originated from patients, healthcare workers, or other environmental contaminants.[9] Several studies have reported on drug-resistant strains of coagulase-negative staphylococci (CoNS) isolated from hospital environments and have exhibited biofilm-producing ability.[10,11] Coagulase-negative staphylococci are frequent inhabitants of hospital environments. In the Philippines, there is a dearth of studies describing the prevalence of biofilm-producing, drug-resistant CoNS in hospital environments

Methods

Results

Conclusion