Department of Medical Microbiology, University of Nairobi, Nairobi, Kenya.
School of Biological Sciences, Jomo Kenyatta University of Agriculture and Technology, Juja, Kenya.
BMC Microbiol. 2018 Nov 14;18(1):187. doi: 10.1186/s12866-018-1332-3.
Typhoid fever remains a public health concern in developing countries especially among the poor who live in informal settlements devoid of proper sanitation and clean water supply. In addition antimicrobial resistance poses a major challenge in management of the disease. This study assessed the antimicrobial susceptibility patterns of Salmonella enterica serotype Typhi (S. Typhi) isolated from typhoid fever cases (2004-2007).
A cross sectional study was conducted on 144 archived S. Typhi isolates (2004-2007) tested against 11 antimicrobial agents by quality controlled disk diffusion technique. Isolates resistant to ampicillin, chloramphenicol, and cotrimoxazole were considered Multidrug resistant (MDR). Thirty MDR isolates were selected randomly and further tested using minimum inhibitory concentration (MIC) E-test.
Sixteen percent (23/144) of the isolates were susceptible to all the antibiotics tested while 68% were resistant to three or more of the 11 antibiotics tested. The isolates showed a high susceptibility to ceftriaxone (94%) and gentamicin (97%). A high percentage of resistance was observed for the conventional first-line antibiotics; ampicillin (72%), chloramphenicol (72%), and cotrimoxazole (70%). Sixty-nine percent of the isolates (100/144) showed reduced susceptibility to ciprofloxacin. All the 30 (100%) isolates selected for MIC test were susceptible to amoxicillin-clavulanic acid. All except one of the 30 isolates were susceptible to ceftriaxone while majority 21 (70%) recorded an intermediate susceptibility to ciprofloxacin with MIC of 0.12-0.5 μg/mL.
A large proportion of S. Typhi isolates were MDR and also showed reduced susceptibility to ciprofloxacin. Fluoroquinolone resistance is emerging and this may pose a challenge in treatment of typhoid in future. There is need for routine surveillance to monitor this phenotype in clinical settings.
伤寒在发展中国家仍然是一个公共卫生问题，特别是在那些生活在缺乏适当卫生和清洁供水的非正规住区的穷人中。此外，抗菌素耐药性对疾病的治疗构成了重大挑战。本研究评估了 2004 年至 2007 年从伤寒病例中分离的伤寒沙门氏菌血清型 Typhi（S. Typhi）的抗菌素敏感性模式。
对 2004 年至 2007 年的 144 株存档的 S. Typhi 分离株进行了横断面研究，使用质量控制的圆盘扩散技术对 11 种抗菌素进行了测试。对氨苄西林、氯霉素和复方磺胺甲恶唑耐药的分离株被认为是多药耐药（MDR）。随机选择 30 株 MDR 分离株，并使用最小抑菌浓度（MIC）E 试验进一步测试。
144 株分离株中，16%（23/144）对所有测试的抗生素均敏感，而 68%对 11 种测试抗生素中的 3 种或更多种耐药。分离株对头孢曲松（94%）和庆大霉素（97%）显示出高度敏感性。对传统一线抗生素，即氨苄西林（72%）、氯霉素（72%）和复方磺胺甲恶唑（70%）的耐药率较高。69%的分离株（100/144）对环丙沙星显示出较低的敏感性。所有 30 株（100%）用于 MIC 测试的分离株均对阿莫西林-克拉维酸敏感。除 1 株外，所有 30 株分离株均对头孢曲松敏感，而大多数 21 株（70%）对环丙沙星的敏感性为中间水平，MIC 为 0.12-0.5μg/ml。
相当一部分 S. Typhi 分离株是多药耐药的，并且对环丙沙星的敏感性也降低了。氟喹诺酮类药物耐药性正在出现，这可能对未来治疗伤寒构成挑战。需要进行常规监测，以监测临床环境中的这种表型。
