Association between Type A
            <i>blaZ</i>
            Gene Polymorphism and Cefazolin Inoculum Effect in Methicillin-Susceptible Staphylococcus aureus

Lee, Sun Hee; Park, Wan Beom; Lee, Shinwon; Park, Sohee; Kim, Shin‐Woo; Lee, Jong Myung; Chang, Hyun Ha; Kwon, Ki Tae; Choe, Pyoeng Gyun; Kim, Nam Joong; Kim, Hong Bin; Oh, Myoung‐don

doi:10.1128/aac.01517-16

Cited by 11 publications

(15 citation statements)

References 25 publications

(45 reference statements)

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“…Moreover, the association between the agr type and CIE was more apparent in the type A blaZ gene-positive MSSA isolates. Although type A blaZ genotype has been positively associated with CIE, it is not uncommon to find MSSA isolates with the type A blaZ gene that do not show CIE [342728]. In our study, almost all of the MSSA with agr type III and type A blaZ genotype exhibited CIE.…”

Section: Discussionmentioning

confidence: 50%

The Cefazolin Inoculum Effect and the Presence of type A blaZ Gene according to agr Genotype in Methicillin-Susceptible Staphylococcus aureus Bacteremia

Lee

Park

et al. 2019

Infect Chemother

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BackgroundRecent data suggests the inoculum effect of methicillin-susceptible Staphylococcus aureus (MSSA) against beta-lactam antibiotics and their association with functionality or genotypic variation of agr locus.MethodsMSSA blood isolates were collected at a tertiary care hospital in Korea from June 2014 to December 2017. The functionality of the agr operon was measured by δ-hemolysin assays. Multiplex PCR was performed to determine the agr genotype. The cefazolin minimum inhibitory concentrations (MICs) at a high inoculum concentration (~5 × 107 CFU/ml) were compared to the MICs at a standard inoculum concentration (~5 × 105 CFU/ml) to identify strains with the cefazolin inoculum effect (CIE). The DNA sequencing of blaZ gene was performed to classify the blaZ genotype.ResultsAmong the 195 MSSA blood isolates, agr genotype I was most common (68.2%), followed by type III (16.4%), type IV (9.2%), and type II (6.2%). Sixty-seven (34.3%) MSSA isolates had dysfunctional agr, but neither CIE nor blaZ genotype was associated with dysfunctional agr. The MSSA with agr type III genotype exhibited significantly higher CIE positivity (agr III 43.8% vs. non-agr III 5.5%, P <0.01) and erythromycin/clindamycin resistance. In the subgroup analysis of type A blaZ possessing MSSA, almost all of the agr III MSSA isolates exhibited CIE, while only 20% of non-agr III isolates had CIE (P <0.01).ConclusionIn MSSA blood isolates, CIE might be associated with agr genotype rather than with dysfunctional agr.

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Section: Discussionmentioning

confidence: 50%

The Cefazolin Inoculum Effect and the Presence of type A blaZ Gene according to agr Genotype in Methicillin-Susceptible Staphylococcus aureus Bacteremia

Lee

Park

et al. 2019

Infect Chemother

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“…Therefore, we can improve the outcomes of MSSA bacteraemia if we have tools to rapidly identify the CIE-positive strain. Therefore, it may be necessary to develop a reliable method for rapid detection of CIE positivity in a clinical setting as this is currently not available [27].…”

Section: Discussionmentioning

confidence: 99%

Comparative outcomes of cefazolin versus nafcillin for methicillin-susceptible Staphylococcus aureus bacteraemia: a prospective multicentre cohort study in Korea

Lee

Song

Jung

et al. 2018

Clinical Microbiology and Infection

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“…The inoculum effect has been defined as a significant elevation in the cefazolin minimum inhibitory concentration with an inoculum higher than standard bacterial inoculum [ 24 ]. This is usually due to the production of a type A β-lactamase that can hydrolyze cefazolin [ 25 ]. Two recent review articles summarized clinical reports focused on cefazolin inoculum effect [ 9 , 10 ].…”

Section: Discussionmentioning

confidence: 99%

Efficacy and safety of cefazolin versus antistaphylococcal penicillins for the treatment of methicillin-susceptible Staphylococcus aureus bacteremia: a systematic review and meta-analysis

Shi

Xiao²,

Zhang

et al. 2018

BMC Infect Dis

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BackgroundAntistaphylococcal penicillins (ASPs) and cefazolin have become the most frequent choices for the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) infections. However, the best therapeutic agent to treat MSSA bacteremia remains to be established.MethodsWe conducted a systematic review and meta-analysis to evaluate the efficacy and safety of these two regimens for the treatment of MSSA bacteremia. PubMed, EMBASE and the Cochrane Library from inception to February 2018 were searched. The primary outcome was mortality. The secondary outcomes included treatment failure, recurrence of bacteremia, adverse effects (AEs) and discontinuation due to AEs. Data were extracted and pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.ResultsA total of ten observational studies met the inclusion criteria. The results indicate that compared to ASPs, cefazolin was associated with significant reduction in mortality (OR, 0.69; 95% CI, 0.58 to 0.82; I2 = 3.4%) and clinical failure (OR, 0.56; 95% CI, 0.37 to 0.85; I2 = 44.9%) without increasing the recurrence of bacteremia (OR, 1.12; 95% CI, 0.94 to 1.34; I2 = 0%). There were no significant differences for the risk of anaphylaxis (OR, 0.91; 95% CI, 0.36 to 2.99; I2 = 0%) or hematotoxicity (OR, 0.56; 95% CI, 0.17 to 1.88; I2 = 0%). However, nephrotoxicity (OR, 0.36; 95% CI, 0.16 to 0.81; I2 = 0%) and hepatotoxicity (OR, 0.12; 95% CI, 0.04 to 0.41; I2 = 0%) were significantly lower in the cefazolin group. Moreover, cefazolin was associated with lower probability of discontinuation due to AEs compared with the ASPs (OR, 0.24; 95% CI, 0.12 to 0.48; I2 = 18%).ConclusionThe results of present study favor the application of cefazolin and should be regarded as important evidence to help make clinical decisions in choosing a treatment option for treating MSSA bacteremia.Electronic supplementary materialThe online version of this article (10.1186/s12879-018-3418-9) contains supplementary material, which is available to authorized users.

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Association between Type A blaZ Gene Polymorphism and Cefazolin Inoculum Effect in Methicillin-Susceptible Staphylococcus aureus

Cited by 11 publications

References 25 publications

The Cefazolin Inoculum Effect and the Presence of type A blaZ Gene according to agr Genotype in Methicillin-Susceptible Staphylococcus aureus Bacteremia

The Cefazolin Inoculum Effect and the Presence of type A blaZ Gene according to agr Genotype in Methicillin-Susceptible Staphylococcus aureus Bacteremia

Comparative outcomes of cefazolin versus nafcillin for methicillin-susceptible Staphylococcus aureus bacteraemia: a prospective multicentre cohort study in Korea

Efficacy and safety of cefazolin versus antistaphylococcal penicillins for the treatment of methicillin-susceptible Staphylococcus aureus bacteremia: a systematic review and meta-analysis

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