Herruzo R, Ruiz G, Vizcaino M J, Rivas L, Pérez-Blanco V, Sanchez M
Departamento de Medicina Preventiva y Salud Pública y Microbiologia, UAM, Madrid.
Servicio de Microbiología Hospital Universitario La Paz, Madrid.
J Prev Med Hyg. 2017 Mar;58(1):E34-E41.
We have found clusters of Klebsiella pneumoniae with OXA48-carbepenemase cases in some hospital rooms, and decided to investigate whether bathroom siphons could be a reservoir for OXA48 bacteria, as occurs with K. oxytoca with other types of carbepenemases.
We evaluated the microbial competition between strains with OXA48 and VIM carbepenemases, in diluted nutrient-broth, on a slime germ-carrier. We compared the number of colonies at 5 and 10 days on the contaminated carriers with one or two strains. We evaluated the dissemination of K. pneumoniae with carbepenemase OXA48 or VIM from thumbs and index fingers of volunteers, to standard surfaces (20 glass germ-carrier by each volunteer). After, we counted the number of microorganisms on each carrier. Microbiological weekly studies of faecal microbiota of all patients were obtained in Traumatology and Oncology. Moreover, we studied samples of the sink in their rooms. PCR and MLST sequence-type was determined in all K. pneumoniae diagnosed from patients and sinks.
A large possibility of diffusion from contaminated hands, which continue to transmit high numbers of microorganisms after more than 10 successive surface contacts, was highlighted; OXA bacteria were more persistent than VIM bacteria. Microbial competition studies showed that VIM bacteria are inhibited by OXA ones. These observations can explain the concentration of cases of K. pneumoniae OXA48 in some rooms in Traumatology and Oncology, producing a significant OR between rooms with OXA48-bacteria-contaminated siphons and other rooms (3.1 and 3.3 respectively). Risk was lowered after changing or disinfecting (heat plus chlorinated disinfectant) the contaminated siphons. Siphon colonization by VIM bacteria was not related with human infections by similar microorganisms.
Bathroom siphons can be a reservoir for K. pneumoniae OXA48 and lead to outbreaks. Outbreaks can be controlled by replacement or heat plus chemical treatment of the sink-siphons.
我们在一些医院病房中发现了携带OXA48碳青霉烯酶的肺炎克雷伯菌聚集情况，因此决定调查浴室虹吸管是否可能成为OXA48细菌的储存源，就像产酸克雷伯菌与其他类型碳青霉烯酶的情况一样。
我们在稀释的营养肉汤中，于黏液菌载体上评估了携带OXA48和VIM碳青霉烯酶的菌株之间的微生物竞争。我们比较了被一种或两种菌株污染的载体在第5天和第10天的菌落数量。我们评估了携带碳青霉烯酶OXA48或VIM的肺炎克雷伯菌从志愿者的拇指和食指传播到标准表面（每位志愿者20个玻璃菌载体）的情况。之后，我们计算了每个载体上的微生物数量。在创伤科和肿瘤科对所有患者的粪便微生物群进行了每周一次的微生物学研究。此外，我们还研究了他们病房水槽的样本。对从患者和水槽中诊断出的所有肺炎克雷伯菌进行了PCR和多位点序列分型测定。
突出显示了来自污染手部的大量传播可能性，在连续超过10次表面接触后仍继续传播大量微生物；OXA细菌比VIM细菌更具持久性。微生物竞争研究表明，VIM细菌受到OXA细菌的抑制。这些观察结果可以解释创伤科和肿瘤科一些病房中肺炎克雷伯菌OXA48病例的集中情况，在OXA48细菌污染虹吸管的病房与其他病房之间产生了显著的比值比（分别为3.1和3.3）。更换或消毒（加热加含氯消毒剂）污染的虹吸管后风险降低。VIM细菌在虹吸管中的定植与类似微生物引起的人类感染无关。
浴室虹吸管可能是肺炎克雷伯菌OXA48的储存源并导致暴发。暴发可通过更换水槽虹吸管或对其进行加热加化学处理来控制。
