Zaidi Mussaret B, Leon Verónica, Canche Claudia, Perez Carolina, Zhao Shaohua, Hubert Susannah K, Abbott Jason, Blickenstaff Karen, McDermott Patrick F
Depto. de Investigacion, Laboratorio de Investigación, Hospital General O'Horan, Av. Itzaes x Jacinto Canek, Mérida C.P. 97000, Yucatan, Mexico.
J Antimicrob Chemother. 2007 Aug;60(2):398-401. doi: 10.1093/jac/dkm168. Epub 2007 May 24.
We describe the emergence and dissemination of multidrug-resistant (MDR) Salmonella Typhimurium in humans, retail meat and food animals from Yucatan, Mexico.
Salmonella Typhimurium isolates were collected through an active surveillance system and tested for susceptibility to 12 antimicrobial agents. Isolates that were non-susceptible to ceftriaxone were tested with 10 additional antimicrobials and assayed by PCR for the presence of CMY, CTX-M, SHV, TEM and OXA beta-lactamase genes. Plasmid-borne phenotypes were identified by transfer to susceptible Escherichia coli. Isolates from humans, retail meat and food animals were compared by PFGE to determine genetic relatedness.
MDR Salmonella Typhimurium containing a plasmid-mediated blaCMY-2 AmpC beta-lactamase rose from 0% (0/27) during 2000 and 2001 to 75% (63/84) in 2004 and 2005 (P<0.0001). MDR blaCMY-2 Salmonella Typhimurium (n=115) was most common in ill children (44.3%) and pork or swine intestine (36.5%). In several cities, MDR blaCMY-2 Salmonella Typhimurium from retail meat or swine intestine exhibited PFGE patterns and antibiograms indistinguishable from those in strains recovered from hospitalized children. The CMY gene was transferred to E. coli by electroporation, along with resistance to three to six other antimicrobials. Children with MDR blaCMY-2 Salmonella Typhimurium infection (n=39) had a higher frequency of systemic infection (13% versus 0%), mortality (8% versus 0%) and hospital re-admission due to protracted diarrhoea (28% versus 17%) than children with non-MDR-Salmonella Typhimurium (n=24), although the difference was not statistically significant.
The rapid and widespread dissemination of MDR blaCMY-2 Salmonella Typhimurium in Mexico calls for urgent interventions to contain this potentially fatal pathogen.
我们描述了多重耐药鼠伤寒沙门氏菌在墨西哥尤卡坦半岛人类、零售肉类及食用动物中的出现及传播情况。
通过主动监测系统收集鼠伤寒沙门氏菌分离株，并检测其对12种抗菌药物的敏感性。对头孢曲松不敏感的分离株再用另外10种抗菌药物进行检测，并通过聚合酶链反应检测CMY、CTX - M、SHV、TEM和OXAβ - 内酰胺酶基因的存在情况。通过将质粒携带的表型转移至敏感的大肠杆菌来进行鉴定。通过脉冲场凝胶电泳比较来自人类、零售肉类及食用动物的分离株，以确定遗传相关性。
携带质粒介导的blaCMY - 2 AmpCβ - 内酰胺酶的多重耐药鼠伤寒沙门氏菌在2000年和2001年期间占比从未出现（0/27）上升至2004年和2005年的75%（63/84）（P<0.0001）。多重耐药blaCMY - 2鼠伤寒沙门氏菌（n = 115）在患病儿童（44.3%）以及猪肉或猪肠道（36.5%）中最为常见。在几个城市，来自零售肉类或猪肠道的多重耐药blaCMY - 2鼠伤寒沙门氏菌呈现出的脉冲场凝胶电泳图谱和抗菌谱与从住院儿童中分离出的菌株无法区分。通过电穿孔法，CMY基因连同对三到六种其他抗菌药物的耐药性被转移至大肠杆菌。与非多重耐药鼠伤寒沙门氏菌感染的儿童（n = 24）相比，多重耐药blaCMY - 2鼠伤寒沙门氏菌感染的儿童（n = 39）发生全身感染的频率更高（13%对0%）、死亡率更高（8%对0%）以及因持续性腹泻再次入院的比例更高（28%对17%），尽管差异无统计学意义。
多重耐药blaCMY - 2鼠伤寒沙门氏菌在墨西哥的迅速广泛传播，需要采取紧急干预措施来控制这种潜在致命病原体。
