Shah Pratima, Baral Ratna, Agrawal C S, Lamsal Madhab, Baral Dharanidhar, Khanal Basudha
Department of Microbiology & Infectious Diseases, B.P. Koirala Institute of Health Sciences (BPKIHS), Dharan, Sunsari 56700, Nepal.
Department of Surgery, B.P. Koirala Institute of Health Sciences (BPKIHS), Dharan, Sunsari 56700, Nepal.
Int J Microbiol. 2020 Sep 12;2020:8880403. doi: 10.1155/2020/8880403. eCollection 2020.
The occurrence of urinary tract infection in presence of urolithiasis is frequently noted; however, microbial agents of urolithiasis and their antimicrobial susceptibility patterns remain underinvestigated. This study aimed to identify the microorganisms isolated from urine and stone matrices to determine their antimicrobial susceptibility, to find the association between the pathogens of urine and stone matrices, and to perform the biochemical analysis of stones.
A total of 88 cases of urolithiasis admitted for elective stone removal at Department of surgery, B.P. Koirala Institute of Health Sciences (BPKIHS), were enrolled. Preoperative urine culture and postoperative stone culture were performed. Isolation, identification, and AST were done by the standard microbiological technique. Further qualitative biochemical analysis of stones was also attempted.
Among 88 stone formers recruited, culture of urine, whole stone, and nidus yielded the growth of bacteria 44, 32, and 30, respectively. Bacteria isolated from urine culture correlated with those from stone matrices with a sensitivity of 90%, specificity of 79.69%, PPV of 63.64%, and NPV of 95.45%. (46.7%) was the most common bacteria followed by (16.7%) and (13.3%) from urine and stone cultures. Almost all the uropathogens isolated were susceptible to commonly used antibiotics. Calcium oxalate (84.1%) was common biochemical constituent found in stone formers followed by calcium oxalate + phosphate (8%).
The association of microorganism isolated from urine and nidus culture was significant that can predict the source of infective stone; however, in some cases, microorganisms and the antimicrobial susceptibility pattern from urine and nidus were different. This study emphasizes the use of appropriate antimicrobial agents to prevent the regrowth of residual stones and minimize the risk of infectious complications after surgical removal of stones.
尿路结石患者中尿路感染的发生屡见不鲜；然而，尿路结石的微生物病原体及其抗菌药物敏感性模式仍未得到充分研究。本研究旨在鉴定从尿液和结石基质中分离出的微生物，以确定其抗菌药物敏感性，找出尿液和结石基质病原体之间的关联，并对结石进行生化分析。
纳入了88例在BP Koirala卫生科学研究所（BPKIHS）外科接受择期结石清除术的尿路结石患者。进行了术前尿培养和术后结石培养。通过标准微生物技术进行分离、鉴定和药敏试验。还尝试对结石进行进一步的定性生化分析。
在招募的88例结石形成者中，尿液、整块结石和结石核心培养分别有44、32和30例细菌生长。从尿培养中分离出的细菌与结石基质中的细菌相关，敏感性为90%，特异性为79.69%，阳性预测值为63.64%，阴性预测值为95.45%。大肠埃希菌（46.7%）是尿液和结石培养中最常见的细菌，其次是肺炎克雷伯菌（16.7%）和粪肠球菌（13.3%）。几乎所有分离出的尿路病原体对常用抗生素敏感。草酸钙（84.1%）是结石形成者中常见的生化成分，其次是草酸钙 +磷酸盐（8%）。
从尿液和结石核心培养中分离出的微生物之间存在显著关联，这可以预测感染性结石的来源；然而，在某些情况下，尿液和结石核心中的微生物及其抗菌药物敏感性模式有所不同。本研究强调使用适当的抗菌药物来预防残留结石的再生长，并将结石手术切除后感染并发症的风险降至最低。
