Contents lists available at ScienceDirect LWT - Food Science and Technology journal homepage: www.elsevier.com/locate/lwt Pathogenicity and antibiotic resistance of coagulase-negative staphylococci isolated from retailing chicken meat Huawei Wang a , Huhu Wang b , Yun Bai b , Xinglian Xu a,* , Guanghong Zhou a,b a Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, PR China b National Center of Meat Quality and Safety Control, Nanjing Agricultural University, Nanjing 210095, PR China ARTICLE INFO Keywords: Coagulase-negative staphylococci Raw chicken meat Pathogenicity Antibiotic resistance ABSTRACT Diverse coagulase-negative staphylococci (CNS) species isolated from meat are previously reported and con- sidered as potential pathogenic staphylococci through obtain horizontal transferred elements (e.g. toxic, anti- biotic resistance factors) from other bacteria. In this study, prevalence, homology and pathogenicity of CNS isolated from 180 raw chicken meat samples in retail markets were studied. The overall prevalence of CNS was 11.7% and centralized in 69.2% of Staphylococcus epidermidis and 30.8% of Staphylococcus warneri among diverse sources (including different retail settings, suppliers and products). Molecular typing showed highly homo- genous patterns in the same species. Antibiotic susceptibility test revealed a common penicillin and ery- thromycin resistance among all of CNS, while 17 S. epidermidis isolates displayed multidrug resistance of gen- tamycin (GM)-kanamycin (K)-penicillin (P)-erythromycin (E), except one methicillin-resistant S. epidermidis isolate which was typed in staphylococcal cassette chromosome mec (SCCmec) Ⅴ. Conclusively, diverse sourced raw chicken meat products exhibited a centralized prevalence of S. epidermidis and S. warneri, and a highly homogenous of genome in the same CNS specie. Though the negative toxigenicity of CNS was determined, constant multidrug resistance in S. epidermidis and P-E resistance in CNS need to be highly concerned regarding human health. 1. Introduction CNS in foods are earlier regarded as food-associated saprophytes (Becker, Heilmann, & Peters, 2014; Fijalkowski, Peitler, & Karakulska, 2016), which are normally inhabited on skin and mucous membrane to multiply as non-infectious bacterium (Piette & Verschraegen, 2009) or contributed to the fermentation of sausages (Blaiotta et al., 2004; Sánchez Mainar, Matheuse, De Vuyst, & Leroy, 2017), particularly, as previously studied (Becker et al., 2014; Ruiz, Barragan, Sesena, & Palop, 2016), S. epidermidis is commonly reported as predominant CNS among diverse food-related settings. Many authors have suggested that CNS can possess or acquire mobile pathogenic factors (e.g. exotoxins, enterotoxins, adherence factors, leukocidins and antibiotic resistance) in the forms of transposons, pathogenicity islands (PIs), plasmids and phages, similar to Staphylococcus aureus, turn into opportunistic food- borne pathogen causing severe infection or food poisoning, to date, correlative genotypic and phenotypic characterizations were de- termined as previously reported (Arciola, Baldassarri, & Montanaro, 2001; Bhargava & Zhang, 2014; Cunha, Peresi, Calsolari, & Araújo Júnior, 2006; Fijalkowski et al., 2016). Currently, the methods of determination of CNS are developed from classic biochemical isolation to molecular identification (e.g. specific DNA sequencing and protein characterizing) (Fijalkowski et al., 2016; Huber et al., 2011). Further- more, as previously described, PFGE (golden molecular typing stan- dard) and random amplified Polymorphic DNA-polymerase chain re- action (RAPD-PCR) are commonly used for molecular typing of CNS (Bhargava & Zhang, 2014; Iacumin, Comi, Cantoni, & Cocolin, 2006; Kawano et al., 1996). Antibiotic resistance of CNS is an emerging important concern re- garding public health in the past decades, constant works have con- firmed the prevalent antibiotic resistance of CNS isolated from animal- origin foods. (Bhargava & Zhang, 2014; Fijalkowski et al., 2016; Kawano et al., 1996; Perillo et al., 2012; Wang et al., 2013). It is de- monstrated that CNS serve as a reservoir for mecA which encoding penicillin-binding protein 2a (PBP2a) (Bhargava & Zhang, 2014; Huber et al., 2011; Wang et al., 2013), and it is hypothesized that methicillin- resistant CNS is responsible for the emergence of methicillin-resistant S. aureus (MRSA) which pose a serious life threat during infections. In recent years, routine antibiotic (penicillin, erythromycin and tetra- cycline etc.) resistances are confirmed among many CNS species https://doi.org/10.1016/j.lwt.2017.12.029 Received 20 July 2017; Received in revised form 6 December 2017; Accepted 11 December 2017 * Corresponding author. E-mail address: xlxu@njau.edu.cn (X. Xu). LWT - Food Science and Technology 90 (2018) 152–156 Available online 12 December 2017 0023-6438/ © 2017 Elsevier Ltd. All rights reserved. T