Staphylococcus aureus isolates colonizing and infecting cirrhotic and liver-transplantation patients: comparison of molecular typing and virulence factors

Larissa Marques De Oliveira,Edson Abdala,Anna S Levin,Luiz C D’ Alburquerque,George R Golding,Flávia Rossi ,Inneke M Van Der Heijden ,Maristela Pinheiro Freire ,Sílvia Figueiredo Costa

doi:10.1186/s12866-015-0598-y

Abstract

BackgroundS. aureus is an important agent of colonization and infection in liver transplant patients. It harbors several virulence factors that can increase its pathogenicity. However, studies of virulence and molecular typing of MRSA in cirrhotic and liver transplantation patients are scarce.ResultsHere we use SCCmec, PFGE, spa typing, MLST and virulence factors to characterize MRSA isolates in pre and post liver transplantation patients. Sixteen (13 %) of 126 cirrhotic and 15 of the 64 liver-transplanted patients (23 %) were colonized by MRSA (p = 0.091). SCCmec types I, II and III that are generally associated with nosocomial infections were identified in 91 % of the isolates. None of the isolates carried PVL, adhesion factors and fib gene. Only three MRSA colonized isolates carried tst gene and were characterized as SCCmec type I and t149. Ten spa types and five STs were identified; t002 and ST105 were the most frequent profiles. Spa types and ST1510 never described in Brazil and a new spa type t14789 were identified. Nineteen PFGE subtypes were found and grouped into nine types. There was a predominant cluster, which was related to the New York/Japanese epidemic clone and harboured SCCmec type II identified in both cirrhotic and post-transplantation patients. Based on SCCmec and virulence factors the MRSA isolates belonged to NY/Jpn clone seen be more similar to the USA100 MRSA isolates.ConclusionsAlthough without significance, liver-transplantation was more frequently colonized by MRSA than cirrhotic patients. The most frequent SCCmec was type II, and the predominant cluster was related to the New York/Japanese clone. A new spa t14789, and ST1510 never reported in Brazil were identified.

Highlights

S. aureus is an important agent of colonization and infection in liver transplant patients
Cirrhotic patients are more frequently colonized by Methicillin-resistant Staphylococcus aureus (MRSA) than the general population and the burden of infectious diseases pre and post liver transplantation is clearly attributable to the dysfunction of defensive mechanisms of the host, because of cirrhosis, as well as because of the use of immunosuppressive agents [4]
According to chart reviews and the questionnaire applied to the 126 listed patients, all patients of list transplantation reported go to the hospital at least once a month for doctor visits or routine tests since the discovery of the disease

Summary

Introduction

S. aureus is an important agent of colonization and infection in liver transplant patients. Studies of virulence and molecular typing of MRSA in cirrhotic and liver transplantation patients are scarce. Cirrhotic patients are more frequently colonized by MRSA than the general population and the burden of infectious diseases pre and post liver transplantation is clearly attributable to the dysfunction of defensive mechanisms of the host, because of cirrhosis, as well as because of the use of immunosuppressive agents [4]. Several virulence factors present in S. aureus that allow de Oliveira et al BMC Microbiology (2015) 15:264 the adherence, colonization and ability to invade tissues can increase the pathogenicity of this microorganism, among them the Panton-Valentine leucocidin (PVL), a toxin that can be able to make pores in the polymorphonuclear cells [5]. Studies of virulence of MRSA in cirrhotic and liver transplantation patients are scarce

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