Central Diagnostic Laboratory, College of Veterinary medicine, Animal resources and Biosecurity, Makerere University, Kampala, Uganda.
Department of Veterinary Pharmacy, Clinics and Comparative Medicine, College of Veterinary Medicine, Animal Resources and Bio-Security Makerere University, Kampala, Uganda.
BMC Microbiol. 2024 Aug 10;24(1):298. doi: 10.1186/s12866-024-03442-x.
Several diagnostic environments in Uganda lack real-time, robust and high-throughput technologies for comprehensive typing of microbes, which is a setback to infectious disease surveillance. This study combined various wet laboratory diagnostics to understand the epidemiology of pathogenic staphylococci isolated from animals in Uganda and the implications for global health security priorities.
A retrospective study was conducted employing records and pathogenic staphylococci (from animals) archived at the Central Diagnostic Laboratory (CDL), Makerere University, Uganda, between January 2012 and December 2019. The bacteria were speciated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and tested for virulence factors [beta lactamases, lecithinase, deoxyribonuclease (DNase), haemolysins] and resistance to ten antimicrobials of clinical and veterinary relevance. Tetracycline and methicillin resistance genes were also tested.
The prevalent diseases were mastitis in cattle and skin infections in dogs. Of the 111 staphylococci tested by MALDI-TOF MS, 79 (71.2%) were Staphylococcus aureus, 27 (24.3%) were Staphylococcus pseudintermedius and 5 (4.5%) were Staphylococcus schleiferi. All these strains expressed haemolysins. The prevalence of strains with lecithinase, penicillinase, cephalosporinase and DNase was 35.9% (14/39), 89.7% (35/39), 0.0% (0/39) and 87.2% (34/39), respectively. Staphylococci were primarily resistant to early penicillins (over 80%), tetracycline (57.7%), and chloramphenicol (46.2%). Minimal resistance was noted with cloxacillin (0.0%), ciprofloxacin (9.6%), and cefoxitin (3.8%). The prevalence of multidrug resistance (MDR) was 78.8% for general staphylococci, 82.2% for S. aureus, 73.1% for S. pseudintermedius, and 60.0% for S. schleiferi. Multidrug resistant staphylococci were significantly more prevalent in the cattle isolates than in the dog isolates (P < 0.05). The prevalence of methicillin-resistant staphylococci (MRS) tested by resistance to cefoxitin and mecA carriage was 3.8%. These four strains were all isolated from dog skin infections. The tetK gene was the most predominant (35.4%), followed by tetM (25.0%).
In resource-constrained settings, the approach of integrated diagnostics promises sustainable disease surveillance and the addressing of current capacity gaps. The emergence of MRS (zoonotic bacteria) in companion animals creates a likelihood of reduced treatment options for related human infections, a threat to global health.
乌干达的一些诊断环境缺乏实时、强大和高通量的综合微生物分型技术，这对传染病监测造成了阻碍。本研究结合了各种湿实验室诊断方法，以了解从乌干达动物中分离出的致病性葡萄球菌的流行病学情况，以及这对全球卫生安全重点的影响。
对 2012 年 1 月至 2019 年 12 月期间保存在乌干达马凯雷雷大学中央诊断实验室（CDL）的记录和致病性葡萄球菌（来自动物）进行了回顾性研究。使用基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）对细菌进行种属鉴定，并检测了毒力因子[β-内酰胺酶、卵磷脂酶、脱氧核糖核酸酶（DNase）、溶血性]和十种与临床和兽医相关的抗菌药物的耐药性。还检测了四环素和甲氧西林耐药基因。
主要疾病是牛乳腺炎和狗皮肤感染。通过 MALDI-TOF MS 测试的 111 株葡萄球菌中，79 株（71.2%）为金黄色葡萄球菌，27 株（24.3%）为中间葡萄球菌，5 株（4.5%）为施氏葡萄球菌。所有这些菌株均表达溶血素。具有卵磷脂酶、青霉素酶、头孢菌素酶和 DNase 的菌株的流行率分别为 35.9%（14/39）、89.7%（35/39）、0.0%（0/39）和 87.2%（34/39）。葡萄球菌主要对早期青霉素（超过 80%）、四环素（57.7%）和氯霉素（46.2%）耐药。仅对氯唑西林（0.0%）、环丙沙星（9.6%）和头孢西丁（3.8%）有最小的耐药性。总的葡萄球菌的多药耐药率（MDR）为 78.8%，金黄色葡萄球菌为 82.2%，中间葡萄球菌为 73.1%，施氏葡萄球菌为 60.0%。耐多药葡萄球菌在牛分离株中明显比在狗分离株中更为常见（P<0.05）。通过头孢西丁耐药性和 mecA 携带检测到耐甲氧西林葡萄球菌（MRS）的流行率为 3.8%。这四株菌均从狗的皮肤感染中分离出来。tetK 基因最为常见（35.4%），其次是 tetM（25.0%）。
在资源有限的环境中，综合诊断方法有望实现可持续的疾病监测，并解决当前的能力差距。在伴侣动物中出现的耐甲氧西林葡萄球菌（人畜共患病细菌）可能会减少相关人类感染的治疗选择，对全球健康构成威胁。
