Nasal and perirectal colonization of vancomycin sensitive and resistant enterococci in patients of paediatrics ICU (PICU) of tertiary health care facilities.

Muhammad Arfat Yameen,Saira Iram,Naeem Akhtar,Abdul Mannan,Shujaat Ali Khan

doi:10.1186/1471-2334-13-156

Abstract

BackgroundEnterococci normally inhabit the intestinal tract of humans and are also a potential pathogen in causing nosocomial infections. The increase in antibiotic resistance and transfer of antibiotic resistance gene to Staphylococcus aureus (S. aureus) due to co-colonization has increased its importance in research. The aim of the study was to evaluate local epidemiology of nasal and rectal colonization with Enterococcus faecalis (E. faecalis) and Enterococcus faecium (E. faecium) in patients of Paediatrics Intensive Care Unit (PICU) and correlation with clinical and socioeconomic factors.MethodsThe nasal and perirectal swab samples were collected from 110 patients admitted in PICUs of three tertiary care hospitals of Rawalpindi Medical College, Pakistan. The identification of enterococci was done by biochemical tests and by PCR for ddl, vanA and vanB genes. Antibiotic susceptibility testing was performed by disc diffusion and MICs were determined for vancomycin, tetracycline, ciprofloxacin and oxacillin only.ResultsOut of 220 nasal and perirectal samples, 09 vancomycin-resistant enterococci (VRE) and 76 vancomycin-susceptible enterococci (VSE), consisting of 40 E. faecalis and 45 E. faecium were isolated. PCR successfully identified both species with ddl primers and VRE with vanA primer. With disc diffusion method, all isolates were resistant to most of the antibiotics tested except linezolid, quinupristin/dalfopristin, teicoplanin and vancomycin. VRE showed resistance to teicoplanin and vancomycin both and none was resistant to linezolid and quinupristin/dalfopristin. Generally, E. faecium isolates were more resistant than E. faecalis. MICs of vancomycin for nasal and perirectal VRE were 512 mg/L and 64 to 512 mg/L respectively. VRE were more in patients with prolonged hospitalization, from urban localities and those having pneumonia.ConclusionPresent study reveals high colonization and antibiotic resistance in enterococcal isolates from nasal and perirectal area. Nasal colonization by enterococci in PICU is more alarming as VRE may cause infection and can transfer this resistance gene to other microorganisms like S. aureus.

Highlights

Enterococci normally inhabit the intestinal tract of humans and are a potential pathogen in causing nosocomial infections
Nasal colonization by enterococci in Paediatrics Intensive Care Unit (PICU) is more alarming as vancomycin-resistant enterococci (VRE) may cause infection and can transfer this resistance gene to other microorganisms like S. aureus
Enterococci normally inhabit the intestinal tract of humans and animals and may colonize the human oral cavity, vagina, hepatobiliary tract and skin of healthy individuals [1]

Summary

Introduction

Enterococci normally inhabit the intestinal tract of humans and are a potential pathogen in causing nosocomial infections. Several factors, including ubiquitous distribution as intestinal flora and the widespread use of broad-spectrum antibiotics and invasive devices have contributed to the emergence of enterococci as important pathogens [7] and perhaps most important is their extensive resistance to a wide range of antimicrobial agents. These properties allow this organism to survive and multiply with a selective advantage over other fecal flora in a hospital environment where antimicrobial agents are heavily used. The aim of the study was to evaluate local epidemiology of nasal and rectal colonization with E. faecalis and E. faecium in PICUs patients and correlation with clinical and socioeconomic factors

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