Angeletti Andrea, Biondi Roberta, Battaglino Giuseppe, Cremonini Eleonora, Comai Giorgia, Capelli Irene, Donati Gabriele, Cevenini Roberto, Donati Manuela, La Manna Gaetano
Department of Experimental, Diagnostic, Specialty Medicine, Nephrology, Dialysis, and Renal Transplant Unit, S. Orsola University Hospital, Via G. Massarenti 9, 40138, Bologna, Italy.
Microbiology, DIMES, University of Bologna, Bologna, Italy.
BMC Nephrol. 2017 Apr 13;18(1):133. doi: 10.1186/s12882-017-0548-z.
Simkania negevensis is an obligate intracellular bacterium belonging to the family Simkaniaceae in the Chlamydiales order. It is considered an ubiquitous microorganism and aquatic environments may be involved as a source of infection for humans. It was just isolated in samples from domestic water supplies and from mains water supplies, like spa water or swimming pool water, confirming its ability to resist to the common chlorination treatments. Evidence indicates a possible role of the microorganism in respiratory tract infections, in gastroenteric disorders and in the pathogenesis of cardiovascular disease, furthermore it has hypothesized that it could play a role in lung transplant rejection. Prevalence and possible effects in nephrology are unknown.
We examined the occurrence of Simkania negevensis in two differents populations, both characterized by a high susceptibility to infectious complications: 105 hemodialysis patients, 105 renal transplant recipients and 105 healthy subjects through the IgG and IgA response to Simkania negevensis in their sera. Serum antibodies to Simkania negevensis were detected by a homemade ELISA performed according to the Kahane's protocol. Furthermore water samples from hemodialytic circuit were collected, to evaluate Simkania negevensis resistance to usual treatment of disinfection.
Our results were unexpected, showing a higher seroprevalence of antibodies against Simkania negevensis in the hemodialysis patients, compared to renal transplant patients (IgG 22% vs 9% - IgA 9% vs 3%). S. negevensis was isolated in all water samples analyzed.
Our study detected for the first time the occurrence of S. negevensis in hemodialysis and in renal transplant patients. Our findings suggest that water used in hemodialysis could be one of the possible sources of S. negevensis infection, without clinical involvement risk for patients.
内格西嗜肺军团菌是一种专性细胞内细菌，属于衣原体目嗜肺军团菌科。它被认为是一种普遍存在的微生物，水环境可能作为人类感染源。它刚刚在家用水供应样本以及诸如温泉水或游泳池水等主要供水样本中被分离出来，证实了其对常见氯化处理的抵抗能力。有证据表明该微生物在呼吸道感染、胃肠道疾病和心血管疾病发病机制中可能发挥作用，此外，有人推测它可能在肺移植排斥反应中起作用。其在肾脏病学中的患病率和可能影响尚不清楚。
我们通过检测两组不同人群血清中针对内格西嗜肺军团菌的IgG和IgA反应，来研究内格西嗜肺军团菌的存在情况。这两组人群都具有易发生感染并发症的特点：105名血液透析患者、105名肾移植受者和105名健康受试者。通过根据卡哈内方案进行的自制酶联免疫吸附测定（ELISA）检测血清中针对内格西嗜肺军团菌的抗体。此外，收集血液透析回路中的水样，以评估内格西嗜肺军团菌对常规消毒处理的抗性。
我们的结果出人意料，与肾移植患者相比，血液透析患者中抗内格西嗜肺军团菌抗体的血清阳性率更高（IgG：22%对9%；IgA：9%对3%）。在所分析的所有水样中都分离出了内格西嗜肺军团菌。
我们的研究首次检测到血液透析患者和肾移植患者中存在内格西嗜肺军团菌。我们的发现表明，血液透析中使用的水可能是内格西嗜肺军团菌感染的可能来源之一，而患者无临床受累风险。
