Egwuatu C C, Ogunsola F T, Iwuafor A A, Akujobi C N, Egwuatu T O, Nnachi A U, Oduyebo O O
Department of Medical Microbiology and Parasitology, Faculty of Medicine, Nnamdi Azikiwe University, Nnewi Campus, Nigeria.
Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Nigeria.
Afr J Infect Dis. 2016 Nov 24;11(1):18-25. doi: 10.4314/ajid.v11i1.4536. eCollection 2017.
The daily use of Trimethoprim-Sulfamethoxazole (TMP-SMX) prophylaxis reduces morbidity and mortality among patients infected with human immunodeficiency virus (HIV) but its impact on increasing antimicrobial resistance rates has been of public health concern, globally. This study investigated the effect of daily TMP-SMX prophylaxis on feacal carriage rates of resistant isolates of in HIV-infected adult patients in Lagos.
A total of 550 HIV-infected patients with CD4-cell counts of less than 350 cells/mm who were eligible for TMP-SMX prophylaxis and attending Lagos University Teaching Hospital, Lagos, Nigeria, were recruited for this study. Stool/rectal swab samples were aseptically collected from the patients and processed using standard methods for culture and sensitivity.
There was a baseline Trimethoprim-Sulfamethoxazole resistance rate of 54% which increased to 77.9% in first 3 months, rising to 96.1% by 6 months and all isolates were resistant by the 9th month. There was also evidence of cross-resistance to other antibiotics with significance in association with TMP-SMX resistance (p<0.0001). The isolates showed a progressive increase in resistance to the tested antibiotics over the 12-month period. The resistance was in the following order: Ampicillin (74% to 82.6% in the first 3 months; 98.3% by the 6th month and 99.4% by the 9th month; all isolates were resistant by the 12th month), Augmentin (32.5% to 47.7% in first 3 months; 76.1% by the 6th month; 86.3% by the 9th month; all isolates were resistant by 12 months), Ceftriaxone (2.0% to 10.8% in first 3 months; 20.6% by the 6th month; 24.2% by the 9th month; 54.3% by the 12 months).
The carriage rate of feacal E. coli resistant to TMP-SMX is common before TMP-SMX prophylaxis. Initiation of TMP-SMX leads to further increase in resistance to TMP-SMX and cross-resistance to other antimicrobials.
每日使用甲氧苄啶 - 磺胺甲恶唑（TMP - SMX）进行预防可降低感染人类免疫缺陷病毒（HIV）患者的发病率和死亡率，但其对抗菌药物耐药率上升的影响在全球范围内一直是公共卫生关注的问题。本研究调查了每日使用TMP - SMX预防对拉各斯HIV感染成年患者粪便中耐药菌株携带率的影响。
本研究招募了550名符合TMP - SMX预防条件且CD4细胞计数低于350个细胞/mm³的HIV感染患者，这些患者在尼日利亚拉各斯的拉各斯大学教学医院就诊。从患者中无菌采集粪便/直肠拭子样本，并使用标准方法进行培养和药敏试验。
甲氧苄啶 - 磺胺甲恶唑的基线耐药率为54%，在最初3个月内升至77.9%，到6个月时升至96.1%，到第9个月时所有分离株均耐药。也有证据表明对其他抗生素存在交叉耐药，且与TMP - SMX耐药显著相关（p<0.0001）。在12个月期间，分离株对所测试抗生素的耐药性呈逐步上升趋势。耐药情况依次为：氨苄西林（最初3个月为74%至82.6%；第6个月为98.3%；第9个月为99.4%；到第12个月时所有分离株均耐药）、阿莫西林克拉维酸（最初3个月为32.5%至47.7%；第6个月为76.1%；第9个月为86.3%；到12个月时所有分离株均耐药）、头孢曲松（最初3个月为2.0%至10.8%；第6个月为20.6%；第9个月为24.2%；到12个月时为54.3%）。
在进行TMP - SMX预防之前，粪便中对TMP - SMX耐药的大肠杆菌携带率很常见。开始使用TMP - SMX会导致对TMP - SMX的耐药性进一步增加以及对其他抗菌药物的交叉耐药。
