Fukuda Akira, Nakamura Hiromi, Umeda Kaoru, Yamamoto Kaori, Hirai Yuji, Usui Masaru, Ogasawara Jun
Food Microbiology and Food Safety Unit, Division of Preventive Veterinary Medicine, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan.
Division of Microbiology, Osaka Institute of Public Health, Osaka, Japan.
JAC Antimicrob Resist. 2022 Mar 25;4(2):dlac031. doi: 10.1093/jacamr/dlac031. eCollection 2022 Apr.
Under non-antimicrobial selective pressure, antimicrobial-resistant bacteria do not easily become dominant in the microbiota. Furthermore, their low levels prevent detection by isolation, resulting in an underestimation of the prevalence of antimicrobial-resistant bacteria.
We evaluated the infiltration of antimicrobial-resistant bacteria and their related β-lactamase genes among healthy people in non-clinical settings.
Cephalosporin- and fluoroquinolone-resistant and genes were quantified in 217 faecal samples from healthy people in non-clinical settings in Japan. colonies grown on deoxycholate hydrogen sulphide-lactose (DHL) agar, with and without antimicrobials (cefotaxime and ciprofloxacin), were quantified, and isolates were analysed for their susceptibility to antimicrobials and the presence of genes. DNA extracted from faecal samples was used to quantify genes using quantitative PCR (qPCR).
The isolation rates of cefotaxime- and ciprofloxacin-resistant were 6.9% and 12.4%, respectively, using agars without antimicrobials, and 12.0% and 24.4%, respectively, using agars with antimicrobials. For samples from which cefotaxime- and ciprofloxacin-resistant were isolated only using agars with antimicrobials, the ratios of cfu on DHL agars with and without antimicrobials were below -2 log. harbouring genes were isolated from 35.0% of the faecal samples using agars, and genes were detected in 65.0% of faecal DNA samples using qPCR.
Among people carrying cefotaxime- and ciprofloxacin-resistant in non-clinical settings, cefotaxime- and ciprofloxacin-resistant were not dominant in half of the subjects. These individuals may play a role as reservoirs of antimicrobial-resistant bacteria.
在无抗菌药物选择压力的情况下，耐药菌在微生物群中不易占据主导地位。此外，其含量较低，难以通过分离检测到，导致耐药菌的流行率被低估。
我们评估了非临床环境中健康人群体内耐药菌及其相关β-内酰胺酶基因的渗入情况。
对来自日本非临床环境中健康人群的217份粪便样本中的头孢菌素耐药菌和氟喹诺酮耐药菌及其基因进行了定量分析。对在含和不含抗菌药物（头孢噻肟和环丙沙星）的脱氧胆酸盐硫化氢乳糖（DHL）琼脂上生长的菌落进行定量分析，并对分离出的菌株进行抗菌药物敏感性分析以及β-内酰胺酶基因检测。从粪便样本中提取的DNA用于通过定量聚合酶链反应（qPCR）对β-内酰胺酶基因进行定量分析。
使用不含抗菌药物的琼脂时，头孢噻肟耐药菌和环丙沙星耐药菌的分离率分别为6.9%和12.4%，使用含抗菌药物的琼脂时分别为12.0%和24.4%。对于仅使用含抗菌药物的琼脂分离出头孢噻肟耐药菌和环丙沙星耐药菌的样本，在含和不含抗菌药物的DHL琼脂上的菌落形成单位（cfu）比值低于-2对数。使用琼脂从35.0%的粪便样本中分离出携带β-内酰胺酶基因的菌株，使用qPCR在65.0%的粪便DNA样本中检测到β-内酰胺酶基因。
在非临床环境中携带头孢噻肟耐药菌和环丙沙星耐药菌的人群中，半数受试者体内的头孢噻肟耐药菌和环丙沙星耐药菌并不占主导地位。这些个体可能作为耐药菌的储存库发挥作用。
