Resistance to erythromycin of Staphylococcus spp. isolates from the food chain

Abstract

The aim of this study was to determine both the occurrence and the genetic basis of resistance to erythromycin among 1 235 <I>Staphylococcus</I> spp. isolates obtained between 2000 and 2006 from (a) raw milk and meat (1 704 samples), (b) foodstuffs produced from these (451 samples), and (c) contact surfaces at processing plants and dairy farms (363 samples) in the Czech Republic. Isolates were screened by broth microdilution method for resistance to erythromycin and further 11 antimicrobial agents. In addition, isolates were screened by agar dilution (erythromycin range 1–128 mg/l) and D-zone test for inducible resistance to macrolides, lincosamides and streptogramin B (iMLS<sub>B</sub>). Forty isolates were found to be either resistant, or intermediate, to erythromycin (3.2% of isolates); of these, more than 50% were identified as <I>S. epidermidis</I>. A total of 15 (1.2%) resistant isolates of staphylococci originated from foodstuffs. Resistance mediated by methylation – i.e. iMLS<sub>B</sub>-resistance (10 isolates with the <I>erm</I>(A) or <I>erm</I> (C) gene) and constitutive MLS<sub>B</sub>-resistance (one isolate with the <I>erm</I> (B) and <I>erm</I> (C) genes) – exhibited a significantly high level of resistance to erythromycin with minimum inhibitory concentrations (MIC) of 64 – >128 mg/l (MIC<sub>mode</sub> = >128 mg/l). In contrast, the efflux mechanism encoded by the <I>msr</I>(A) gene (13 isolates; MIC<sub>range</sub> = 4–128, MIC<sub>mode</sub> = 128 mg/l), the inactivation mechanisms of resistance encoded by the <I>mph</I>(C) gene (three isolates; MIC<sub>range</sub> = 8–32 mg/l), and/or their combination (13 isolates; MIC<sub>range</sub> = 4–128, MIC<sub>mode</sub> = 64 mg/l) led to lower MIC values. The efflux gene <iomsr</I>(A) dominated among the erythromycin-resistant isolates (65% of resistant isolates). This first report on the resistance of <I>Staphylococcus</I> spp. to erythromycin in the Czech Republic illustrates that, while occurrence was low, isolates from food were nevertheless carriers of <I>erm</I> (A), <I>erm</I> (B), <I>erm</I> (C),<I> msr</I>(A) and <I>mph</I>(C) genes for resistance to erythromycin and, therefore, represent a potential thread to humans.

Retail Ready-to-Eat Food as a Potential Vehicle for Staphylococcus spp. Harboring Antibiotic Resistance Genes

“…The most prevalent species identified in RTE food in our study were S. aureus and S. xylosus, which agrees with results reported by other European researchers (21,25). In the tests performed, resistance to at least one antibiotic was observed in 54.9% of the investigated strains.…”

PERFIL DE RESISTÊNCIA A ANTIMICROBIANOS DE Staphylococcus aureus ISOLADOS DE GRANJAS E FRIGORÍFICOS DE SUÍNOS

“…Relatos de multirresistencia em humanos e animais incluindo os suínos, como observado neste estudo são facilmente encontrados na literatura (Turotoglu et al, 2006;Menegotto & Picoli, 2007;Aarestrup et al, 2008;Coelho et al, 2008;Schlegelova et al, 2008;Tenhagen et al, 2009;Kadlec et al, 2010;Rubin et al, 2011).…”

“…A incidência de animais domésticos portadores e infectados com MRSA tem sido descrita com frequência em vários países e espécies animais (Busscher et al, 2006;Weese et al, 2006;Juhász-Kaszanyitzky et al, 2007;Walther et al, 2008), inclusive em suínos e indivíduos que trabalham com a espécie (Armand-Lefevre et al, 2005;Huijsdens et al, 2006;Sergio et al, 2007). Bagcil et al (2007) relataram que, o Staphylococcus aureus presente na mucosa nasal pode ser transmitido entre animais e humanos.…”

What is behind phylogenetic analysis of hospital‐, community‐ and livestock‐associated methicillin‐resistantStaphylococcus aureus?

“…Furthermore, virulence and antimicrobial resistance genes' profiles were determined based on PCR detections of ica A, pvl and mec A, van A and B, erm C and tet K genes under PCR conditions stated previously (Kariyama, Mitsuhata, Chow, Clewell, & Kumon, ; Larsen et al., ; McClure et al., ; Schlegelova et al., ; Strommenger, Kettlitz, Werner, & Witte, ). Positive and negative controls were included with all performed PCR runs.…”