目的:多重耐药(MDR)沙门氏菌菌株的出现,特别是对至关重要的抗菌类如氟喹诺酮类药物和第三和第四代头孢菌素的耐药性,是一个日益增长的公共卫生问题。目前的研究,因此,旨在确定患病率,和毒力基因的存在(invA,stn,和spvC基因),抗菌素耐药性概况,以及β-内酰胺酶抗性基因的存在(blaOXA,blaCTX-M1,blaSHV,和blaTEM)从埃及在Mansoura销售的本地鸡尸体中分离出的沙门氏菌菌株,埃及,以及突出孤立MDR的风险,colistin-,cefepime-,和耐左氧氟沙星的肠道沙门氏菌对公共卫生的影响。
方法:从曼苏拉市的不同家禽商店收集了一百五十只新鲜食用的土鸡尸体,2022年7月至2022年11月之间的埃及。使用标准细菌学技术进行沙门氏菌分离,包括在缓冲蛋白胨水(BPW)中预富集,在RappaportVassiliadis肉汤(RVS)中进行选择性富集,在木糖-赖氨酸-脱氧胆酸盐(XLD)琼脂表面培养。所有疑似沙门氏菌菌落都接受了生化检测,使用载玻片凝集试验的血清学鉴定,和靶向侵袭A基因(invA;沙门氏菌标记基因)的聚合酶链反应(PCR)。之后,对所有经分子验证的分离株进行了毒力基因(stn和spvC)的筛选.通过Kirby-Bauer圆盘扩散法对分离的沙门氏菌菌株对所测试的16种抗菌剂进行了药敏试验,除了粘菌素,其中通过肉汤微量稀释技术确定最小抑制浓度(MIC)。此外,对82株对头孢噻肟耐药的沙门菌进行了靶向β-内酰胺酶耐药基因的多重PCR检测,包括blaOXA,blaCTX-M1,blaSHV,和blaTEM基因。
结果:通过invA沙门氏菌标记基因在18%(27/150)的新鲜食用的本地鸡尸体中进行了分子确认。在129个确认的沙门氏菌分离株中鉴定出12种沙门氏菌血清型,其中最主要的血清型是肯塔基沙门氏菌。肠炎,鼠伤寒杆菌,和S.Molade的发病率为19.4%(25/129),17.1%(22/129),17.1%(22/129),和10.9%(14/129),分别。所有鉴定的沙门氏菌分离株(n=129)对invA和stn基因均为阳性,而只有31.8%(41/129)的分离株对spvC基因呈阳性。129个沙门氏菌验证的分离株中有121个(93.8%)对至少三种抗生素具有抗性。有趣的是,3.9%,14.7%,75.2%的分离株被归类为泛耐药,广泛耐药,和多重耐药,分别。测试的129个分离株的平均MAR指数为0.505。没错,82.2%,82.2%,63.6%,51.9%,50.4%,48.8%,11.6%,分离的沙门氏菌菌株对头孢吡肟耐药达10.1%,粘菌素,头孢噻肟,头孢他啶/克拉维酸,左氧氟沙星,环丙沙星,阿奇霉素,还有美罗培南,分别。82株对头孢噻肟耐药的沙门氏菌中,有31株(37.8%)是β-内酰胺酶生产者,其中blaTEM是最主要的β-内酰胺酶抗性基因,其次是blaCTX-M1和blaOXA基因,分别在21、16和14个分离株中检测到)。
结论:MDR-的高患病率,colistin-,cefepime-,来自本地鸡的沙门氏菌分离株中的耐左氧氟沙星沙门氏菌血清型令人震惊,因为这些抗菌剂在治疗严重的沙门氏菌病中至关重要,并且迫切需要控制兽医学和人类医学中的抗生素使用以保护公众健康。
OBJECTIVE: The emergence of multidrug-resistant (MDR) Salmonella strains, especially resistant ones toward critically important antimicrobial classes such as fluoroquinolones and third- and fourth-generation cephalosporins, is a growing public health concern. The current study, therefore, aimed to determine the prevalence, and existence of virulence genes (invA, stn, and spvC genes), antimicrobial resistance profiles, and the presence of β-lactamase resistance genes (blaOXA, blaCTX-M1, blaSHV, and blaTEM) in Salmonella strains isolated from native chicken carcasses in Egypt marketed in Mansoura, Egypt, as well as spotlight the risk of isolated MDR, colistin-, cefepime-, and levofloxacin-resistant Salmonella enterica serovars to public health.
METHODS: One hundred fifty freshly dressed native chicken carcasses were collected from different poultry shops in Mansoura City, Egypt between July 2022 and November 2022. Salmonella isolation was performed using standard bacteriological techniques, including pre-enrichment in buffered peptone water (BPW), selective enrichment in Rappaport Vassiliadis broth (RVS), and cultivating on the surface of xylose-lysine-desoxycholate (XLD) agar. All suspected Salmonella colonies were subjected to biochemical tests, serological identification using slide agglutination test, and Polymerase Chain Reaction (PCR) targeting the invasion A gene (invA; Salmonella marker gene). Afterward, all molecularly verified isolates were screened for the presence of virulence genes (stn and spvC). The antimicrobial susceptibility testing for isolated Salmonella strains towards the 16 antimicrobial agents tested was analyzed by Kirby-Bauer disc diffusion method, except for colistin, in which the minimum inhibition concentration (MIC) was determined by broth microdilution technique. Furthermore, 82 cefotaxime-resistant Salmonella isolates were tested using multiplex PCR targeting the β-lactamase resistance genes, including blaOXA, blaCTX-M1, blaSHV, and blaTEM genes.
RESULTS: Salmonella enterica species were molecularly confirmed via the invA Salmonella marker gene in 18% (27/150) of the freshly dressed native chicken carcasses. Twelve Salmonella serotypes were identified among 129 confirmed Salmonella isolates with the most predominant serotypes were S. Kentucky, S. Enteritidis, S. Typhimurium, and S. Molade with an incidence of 19.4% (25/129), 17.1% (22/129), 17.1% (22/129), and 10.9% (14/129), respectively. All the identified Salmonella isolates (n = 129) were positive for both invA and stn genes, while only 31.8% (41/129) of isolates were positive for the spvC gene. One hundred twenty-one (93.8%) of the 129 Salmonella-verified isolates were resistant to at least three antibiotics. Interestingly, 3.9%, 14.7%, and 75.2% of isolates were categorized into pan-drug-resistant, extensively drug-resistant, and multidrug-resistant, respectively. The average MAR index for the 129 isolates tested was 0.505. Exactly, 82.2%, 82.2%, 63.6%, 51.9%, 50.4%, 48.8%, 11.6%, and 10.1% of isolated Salmonella strains were resistant to cefepime, colistin, cefotaxime, ceftazidime/clavulanic acid, levofloxacin, ciprofloxacin, azithromycin, and meropenem, respectively. Thirty-one out (37.8%) of the 82 cefotaxime-resistant Salmonella isolates were β-lactamase producers with the blaTEM as the most predominant β-lactamase resistance gene, followed by blaCTX-M1 and blaOXA genes, which were detected in 21, 16, and 14 isolates respectively).
CONCLUSIONS: The high prevalence of MDR-, colistin-, cefepime-, and levofloxacin-resistant Salmonella serovars among Salmonella isolates from native chicken is alarming as these antimicrobials are critically important in treating severe salmonellosis cases and boost the urgent need for controlling antibiotic usage in veterinary and human medicine to protect public health.