Department of Medical Microbiology, University of Pretoria, Pretoria.
School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa.
Sex Transm Dis. 2023 Dec 1;50(12):821-826. doi: 10.1097/OLQ.0000000000001877. Epub 2023 Oct 12.
There is a paucity of Neisseria gonorrhoeae antimicrobial resistance data from resource-constrained settings because of the lack of diagnostic testing and limited scale of surveillance programs. This study aimed to determine the antimicrobial resistance profile of N. gonorrhoeae in the rural Eastern Cape province of South Africa.
Specimens for N. gonorrhoeae culture were obtained from men with urethral discharge and women with vaginal discharge attending primary health care facilities. Direct inoculation of the agar plates was performed followed by culture and drug susceptibility testing using the Etest at the laboratory. Whole-genome sequencing of the isolates was performed to identify resistance-determining variants.
One hundred N. gonorrhoeae isolates were obtained. Most strains were nonsusceptible to ciprofloxacin (76%), tetracycline (75%), and penicillin G (72%). The gyrA S91F mutation was present in 68 of 72 ciprofloxacin-resistant isolates (94%), with concurrent parC mutations in 47 of 68 (69%); gyrA I250M was the only mutation in 4 other resistant strains. One azithromycin-resistant isolate was identified with a minimal inhibitory concentration (MIC) of 8.0 mg/L and the 23S rDNA gene mutation C2597T. The median MIC of cefixime was 0.016 mg/L (range, 0.016-0.064 mg/L), and that of ceftriaxone was 0.016 mg/L (range, 0.016 mg/L). Whole-genome sequencing showed 58 sequence types as revealed in N. gonorrhoeae sequence typing for antimicrobial resistance and 70 sequence types in N. gonorrhoeae multiantigen sequence typing.
This study confirmed high rates of N. gonorrhoeae antimicrobial resistance to ciprofloxacin, penicillin G, and tetracycline in our setting. The MICs of cephalosporins are reassuring for ceftriaxone use in syndromic treatment regimens, but the identification of azithromycin resistance warrants further attention.
由于缺乏诊断检测和有限的监测计划规模，资源有限的环境中淋病奈瑟菌抗微生物药物耐药数据稀缺。本研究旨在确定南非东开普省农村地区淋病奈瑟菌的抗微生物药物耐药谱。
从患有尿道分泌物的男性和患有阴道分泌物的女性中采集淋病奈瑟菌培养标本，在实验室直接接种琼脂平板，然后进行培养和药敏试验，采用 Etest 进行药物敏感性试验。对分离株进行全基因组测序以鉴定耐药决定变异。
共获得 100 株淋病奈瑟菌分离株。大多数菌株对环丙沙星（76%）、四环素（75%）和青霉素 G（72%）不敏感。72 株环丙沙星耐药分离株中存在 gyrA S91F 突变（94%），其中 47 株（69%）存在 parC 突变；4 株其他耐药株仅存在 gyrA I250M 突变。发现 1 株阿奇霉素耐药株，最低抑菌浓度（MIC）为 8.0mg/L，23S rDNA 基因 C2597T 突变。头孢克肟的中位 MIC 为 0.016mg/L（范围为 0.016-0.064mg/L），头孢曲松的 MIC 为 0.016mg/L（范围为 0.016mg/L）。全基因组测序显示，在抗微生物药物耐药性淋病奈瑟菌序列分型中发现了 58 种序列型，在淋病奈瑟菌多抗原序列分型中发现了 70 种序列型。
本研究证实了我们研究环境中淋病奈瑟菌对抗微生物药物环丙沙星、青霉素 G 和四环素的高耐药率。头孢菌素的 MIC 令人放心，可以在综合征治疗方案中使用头孢曲松，但发现阿奇霉素耐药值得进一步关注。
