Noda Tamie, Murakami Koichi, Etoh Yoshiki, Okamoto Fuyuki, Yatsuyanagi Jun, Sera Nobuyuki, Furuta Munenori, Onozuka Daisuke, Oda Takahiro, Asai Tetsuo, Fujimoto Shuji
Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Division of Pathology and Bacteriology, Department of Health Science, Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu, Fukuoka 818-0135, Japan.
Division of Pathology and Bacteriology, Department of Health Science, Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu, Fukuoka 818-0135, Japan.
PLoS One. 2015 Feb 2;10(2):e0116927. doi: 10.1371/journal.pone.0116927. eCollection 2015.
Extended-spectrum β-lactamase (ESBL)-producing Salmonella are one of the most important public health problems in developed countries. ESBL-producing Salmonella strains have been isolated from humans in Asian countries neighboring Japan, along with strains harboring the plasmid-mediated extended-spectrum cephalosporin (ESC)-resistance gene, ampC (pAmpC). However, only a few studies have investigated the prevalence of ESC-resistant Salmonella in chicken products in Japan, which are the main vehicle of Salmonella transmission. The aim of this study was to investigate the prevalence of ESBL-producing, pAmpC-harboring, or carbapenem-resistant Salmonella in chicken products in Japan. In total, 355 out of 779 (45.6%) chicken product samples collected from 1996-2010 contained Salmonella, resulting in 378 distinct isolates. Of these isolates, 373 were tested for resistance to ESCs, cephamycins, or carbapenems. Isolates that showed resistance to one or more of these antimicrobials were then examined by PCR and DNA sequence analysis for the presence of the bla(CMY), bla(CTX-M), bla(TEM), and bla(SHV) resistance genes. Thirty-five resistant isolates were detected, including 26 isolates that contained pAmpC (bla(CMY-2)), and nine ESBL-producing isolates harboring bla(CTX-M) (n = 4, consisting of two bla(CTX-M-2) and two bla(CTX-M-15 genes)), bla(TEM) (n = 4, consisting of one bla(TEM-20) and three bla(TEM-52) genes), and bla(SHV) (n = 1, bla(SHV-12)). All pAmpC-harboring and ESBL-producing Salmonella isolates were obtained from samples collected after 2005, and the percentage of resistant isolates increased significantly from 0% in 2004 to 27.9% in 2010 (P for trend = 0.006). This increase was caused in part by an increase in the number of Salmonella enterica subsp. enterica serovar Infantis strains harboring an approximately 280-kb plasmid containing bla(CMY-2) in proximity to ISEcp1. The dissemination of ESC-resistant Salmonella containing plasmid-mediated bla(CMY-2) in chicken products indicates the need for the development of continuous monitoring strategies in the interests of public health.
产超广谱β-内酰胺酶（ESBL）的沙门氏菌是发达国家最重要的公共卫生问题之一。在日本周边的亚洲国家，已从人类身上分离出产ESBL的沙门氏菌菌株，以及携带质粒介导的超广谱头孢菌素（ESC）抗性基因ampC（pAmpC）的菌株。然而，在日本，作为沙门氏菌传播主要载体的鸡肉产品中，对ESC耐药的沙门氏菌的流行情况仅有少数研究进行过调查。本研究的目的是调查日本鸡肉产品中产ESBL、携带pAmpC或耐碳青霉烯类的沙门氏菌的流行情况。从1996年至2010年收集的779份鸡肉产品样本中，共有355份（45.6%）含有沙门氏菌，共分离出378株不同的菌株。对其中373株菌株进行了对ESC、头孢霉素或碳青霉烯类药物的耐药性检测。对显示对这些抗菌药物中一种或多种耐药的菌株，随后通过PCR和DNA序列分析检测bla(CMY)、bla(CTX-M)、bla(TEM)和bla(SHV)耐药基因的存在情况。检测到35株耐药菌株，其中包括26株携带pAmpC（bla(CMY-2)）的菌株，以及9株产ESBL的菌株，分别携带bla(CTX-M)（n = 4，包括两个bla(CTX-M-2)和两个bla(CTX-M-15)基因）、bla(TEM)（n = 4，包括一个bla(TEM-20)和三个bla(TEM-52)基因）和bla(SHV)（n = 1，bla(SHV-12)）。所有携带pAmpC和产ESBL的沙门氏菌分离株均来自2005年以后采集的样本，耐药分离株的比例从2004年的0%显著增加到2010年的27.9%（趋势P值 = 0.006）。这种增加部分是由于肠炎沙门氏菌亚种肠炎血清型婴儿沙门氏菌携带一个约280 kb质粒（其中bla(CMY-2)靠近ISEcp1）的菌株数量增加所致。鸡肉产品中携带质粒介导bla(CMY-2)的ESC耐药沙门氏菌的传播表明，为了公众健康利益，需要制定持续监测策略。
