Sex Transm Dis. 2019 Apr;46(4):266-270. doi: 10.1097/OLQ.0000000000000961.
We report on the antimicrobial resistance profile of Neisseria gonorrhoeae isolates and the distribution of tetM genes in isolates with high-level tetracycline resistance in KwaZulu-Natal, South Africa.
Male and female patients presenting with urethral and/or vaginal discharge were recruited into the study. Urethral and cervical secretions were cultured on New York City agar. Confirmatory tests for N. gonorrhoeae included Gram stain, catalase, oxidase, and carbohydrate utilization tests. Beta-lactamase was tested by means of the chromogenic cephalosporin test. Minimum inhibitory concentrations were determined using agar dilution with multipoint inoculation. Polymerase chain reaction with gel electrophoresis was used to detect the presence and type of the tetM gene.
N. gonorrhoeae was isolated from the specimens of 319 (26%) of the 1220 recruited patients. Of these 319 isolates, 71% were resistant to 3 or more drugs. Resistance to azithromycin was found in 68% of the isolates. All isolates showed high-level tetracycline resistance with minimum inhibitory concentration values of 16 and 32 mg/mL. The tetM gene was present in 293 (92%). The American type was found in 264 (90%) and the Dutch type in 29 (10%). Twenty-six (8%) did not carry a tetM gene.
The current syndromic management with dual ceftriaxone and azithromycin is due to the high level of azithromycin resistance factually single-drug therapy. High-level tetracycline resistance based on a resistance mechanism other than ribosome protection by the tetM gene product is present in N. gonorrhoeae infecting South African patients.
我们报告了南非夸祖鲁-纳塔尔省淋病奈瑟菌分离株的抗菌药物耐药谱和高水平四环素耐药分离株中 tetM 基因的分布情况。
我们招募了出现尿道和/或阴道分泌物的男性和女性患者入组研究。在纽约市琼脂上培养尿道和宫颈分泌物。淋病奈瑟菌的确认性检测包括革兰氏染色、触酶、氧化酶和碳水化合物利用试验。通过显色头孢菌素试验检测β-内酰胺酶。使用多点接种琼脂稀释法测定最小抑菌浓度。聚合酶链反应结合凝胶电泳检测 tetM 基因的存在和类型。
在 1220 名招募的患者中，319 名（26%）患者的标本中分离出淋病奈瑟菌。在这 319 株分离株中，71%对 3 种或 3 种以上药物耐药。68%的分离株对阿奇霉素耐药。所有分离株均表现出高水平的四环素耐药，最小抑菌浓度值为 16 和 32mg/mL。293 株（92%）携带 tetM 基因。264 株（90%）为美国型，29 株（10%）为荷兰型。26 株（8%）未携带 tetM 基因。
目前基于 ceftriaxone 和阿奇霉素的综合征管理实际上是由于高水平的阿奇霉素耐药，实际上是单一药物治疗。高水平的四环素耐药是由 tetM 基因产物而非核糖体保护的耐药机制引起的，这在感染南非患者的淋病奈瑟菌中存在。
