Microbial drug resistance : MDR : mechanisms, epidemiology, and disease
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Microb. Drug Resist. · Oct 2016
Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Bloodstream Isolates in a Turkish University Hospital Between 2002 and 2012.
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important pathogens in the hospital environment. Monitoring of this pathogen by molecular characterization and phenotypic methods is important for the development of suitable infection control measures and proper therapy design. In this study, our aim was to investigate the molecular epidemiological characteristics of MRSA bloodstream isolates obtained from patients hospitalized at Ankara University Ibn-i Sina Hospital in a 10-year period (2002-2012) and monitor the possible changes. A total of 134 isolates were characterized according to their antimicrobial susceptibility profiles, biofilm formation capabilities, accessory gene regulator (agr) locus types, presence of genes encoding Panton-Valentine leukocidin (PVL), staphylococcal enterotoxins A-J (SEs A-J), toxic shock syndrome toxin, sasX, and genes associated with biofilm formation (icaD, icaA, IS256) by polymerase chain reaction. The staphylococcal cassette chromosome mec (SCCmec) types of isolates were also defined and their clonal relationships were investigated by pulsed-field gel electrophoresis (PFGE) analysis and multilocus sequence typing was performed for representative isolates obtained by PFGE. ⋯ We have documented the characteristics of the dominant MRSA clone in our hospital, which was a PVL (-), sasX (-) ST239 clone carrying sea (+) with type-III SCCmec, and type-1 agr locus.
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Microb. Drug Resist. · Jul 2016
ReviewMultidrug-Resistant Gram-Negative Bacterial Infections in the Hospital Setting: Overview, Implications for Clinical Practice, and Emerging Treatment Options.
The increasing prevalence of infections due to multidrug-resistant (MDR) gram-negative bacteria constitutes a serious threat to global public health due to the limited treatment options available and the historically slow pace of development of new antimicrobial agents. Infections due to MDR strains are associated with increased morbidity and mortality and prolonged hospitalization, which translates to a significant burden on healthcare systems. In particular, MDR strains of Enterobacteriaceae (especially Klebsiella pneumoniae and Escherichia coli), Pseudomonas aeruginosa, and Acinetobacter baumannii have emerged as particularly serious concerns. ⋯ The rising prevalence of infections due to MDR gram-negative bacteria presents a significant dilemma in selecting empiric antimicrobial therapy in seriously ill hospitalized patients. A prudent initial strategy is to initiate treatment with a broad-spectrum regimen pending the availability of microbiological results allowing for targeted or narrowing of therapy. Empiric therapy with newer agents that exhibit good activity against MDR gram-negative bacterial strains such as tigecycline, ceftolozane-tazobactam, ceftazidime-avibactam, and others in the development pipeline offer promising alternatives to existing agents.
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Microb. Drug Resist. · Jul 2016
Microbiological Characteristics of Unresolved Acute Uncomplicated Cystitis.
This study sought to compare the antimicrobial susceptibility rates between acute uncomplicated cystitis patients with failed initial antimicrobial treatment, who were considered unresolved cases, and newly presenting acute uncomplicated cystitis patients without recent antimicrobial use within 3 months and to determine whether different treatment strategies should be applied according to recent antimicrobial exposure (RAE). Female acute uncomplicated cystitis patients with Escherichia coli growth, who visited our hospital's urology department from 2010 to 2014, were divided according to RAE. The antimicrobial susceptibility of E. coli was compared between the group with RAE and the group with no antimicrobial exposure (NAE) within 3 months. ⋯ RAE was an independent factor for antimicrobial resistance. This study showed that antimicrobial susceptibilities were significantly lower in acute uncomplicated cystitis patients with failed initial antimicrobial treatment, who are defined as unresolved cases. Our results suggest that first-line antimicrobials might show poor efficacy in cases of unresolved, acute uncomplicated cystitis and alternative or secondary antimicrobials should be considered in these cases.
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Microb. Drug Resist. · Mar 2016
In Vitro Antimicrobial Susceptibility of Nontuberculous Mycobacteria in Iran.
Many species of nontuberculous mycobacteria (NTM) have long been identified as important causes of human disease, the incidence of which is rising. Several reports have suggested increasing trend of both in vitro and in vivo resistance to available treatment regimes. The aim of this study was to evaluate antibiotic susceptibility of clinically relevant NTM isolates using standard microbroth dilution test. ⋯ M. simiae was resistant to clarithromycin, doxycycline, isoniazid, and TMP-SMZ, and the majority of isolates showed high levels of resistance to linezolid, ethambutol, ciprofloxacin, streptomycin, and rifampicin. The majority of M. simiae isolates were multidrug resistant. Our data confirm the need for performing of standard susceptibility testing of any clinically important NTM isolate.
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Microb. Drug Resist. · Oct 2015
The Prevalence of Vancomycin-Intermediate Staphylococcus aureus and Heterogeneous VISA Among Methicillin-Resistant Strains Isolated from Pediatric Population in a Turkish University Hospital.
There are limited data regarding the prevalence of vancomycin-intermediate Staphylococcus aureus (VISA)/heterogeneous VISA (hVISA) among pediatric population. Our objective was to determine the distribution of vancomycin and daptomycin minimum inhibitory concentrations (MICs) and explore the phenomenon of vancomycin MIC creep and the VISA/hVISA prevalence among the methicillin-resistant Staphylococcus aureus (MRSA) strains belonging to pediatric population by population analysis profile-area under the curve (PAP-AUC) and Etest macromethod. Vancomycin and daptomycin susceptibilities of 94 pediatric isolates of MRSA were tested by broth microdilution (BMD) and Etest methods. ⋯ To our knowledge, this is the first study investigating the prevalence of VISA/hVISA among MRSA isolated from pediatric patients by PAP-AUC method. Based on our findings, MRSA isolates, which have vancomycin MIC of 2 μg/ml can be investigated for the presence of hVISA. In this study, daptomycin showed potent activity against all isolates and may represent a therapeutic option for MRSA infections.