129株弗氏柠檬酸杆菌临床分离株的耐药性

探讨弗氏柠檬酸杆菌临床分离株对抗菌药物的体外敏感性。研究我院1998年1月～2001年6月从临床标本中分离出的129株弗氏柠檬酸杆菌，测定其对17种抗菌药物的敏感性，分析药敏结果。从痰、尿、脓液、伤口分泌物、血、胆汁、胸水、腹水和静脉导管的临床标本中共分离出129株弗氏柠檬酸杆菌。这129株对17种抗菌药物的耐药率分别为：亚胺培南7．75％，阿米卡星14．72％，头孢吡肟27．9l％，哌拉西林／三唑巴坦34．89％，氨曲南46．51％，头孢噻肟46．51％，头孢曲松49．61％，头孢他啶50．4％，环丙沙星50．4％，妥布霉素53．49％，庆大霉素60．46％，复方磺胺甲口恶唑61．24％，头孢呋辛69．77％，氨苄西林／舒巴坦72．89％，哌拉西林78．29％，头孢西丁89．15％，头孢唑林94．34％。结论对我院弗氏柠檬酸杆菌临床分离株对亚胺培南和阿米卡星耐药率较低，但对包括第三代头孢菌素在内的其它抗菌药物的耐药率高，且存在多重耐药菌株，对其耐药性和耐药机制应加强监测和研究。     

Outbreak of OXA-48-producing Enterobacterales in a haematological ward associated with an uncommon environmental reservoir,France, 2016 to 2019

The hospital water environment, including the wastewater drainage system, is increasingly reported as a potential reservoir for carbapenemase-producing Enterobacterales (CPE). We investigated a persistent outbreak of OXA-48 CPE (primarily Citrobacter freundii) in a haematological ward of a French teaching hospital by epidemiological, microbiological and environmental methods. Between January 2016 and June 2019, we detected 37 new OXA-48 CPE-colonised and/or ‑infected patients in the haematological ward. In October 2017, a unit dedicated to CPE-colonised and/or ‑infected patients was created. Eleven additional sporadic acquisitions were identified after this date without any obvious epidemiological link between patients, except in one case. Environmental investigations of the haematological ward (June–August 2018) identified seven of 74 toilets and one of 39 drains positive for OXA-48 CPE (seven C. freundii, one Enterobacter sakazakii, one Escherichia coli). Whole genome comparisons identified a clonal dissemination of OXA-48-producing C. freundii from the hospital environment to patients. In addition to strict routine infection control measures, an intensive cleaning programme was performed (descaling and bleaching) and all toilet bowls and tanks were changed. These additional measures helped to contain the outbreak. This study highlights that toilets can be a possible source of transmission of OXA-48 CPE.     

潜在致病性的弗氏枸橼酸杆菌的筛查

目的 筛查具有潜在致病性的弗氏枸橼酸杆菌。方法 对从河南省睢县分离到的36株弗氏枸橼酸杆菌进行黏附HEp-2细胞的检测,以及与HEp-2细胞(MOI: 100)作用10 h后的乳酸脱氢酶(LDH)释放情况分析。同时比较弗氏枸橼酸杆菌CF74(Citrobacter freundii 74)、CF72(Citrobacter freundii 72)、肠聚集性大肠埃希菌(Enteroaggregative E. coli,EAEC)、肠致病性大肠埃希菌(Enteropathogenic E. coli,EPEC)2348/69和HB101的黏附和细胞毒性差异。结果 16株弗氏枸橼酸杆菌几乎没有黏附性,黏附指数1;18株弗氏枸橼酸杆菌具有中等强度的黏附性,黏附指数100;2株弗氏枸橼酸杆菌CF74和CF65(Citrobacter freundii 65)具有强的黏附性。与HEp-2细胞作用10 h后,除了CF74(24.4%),其余的35株弗氏枸橼酸杆菌具有低的LDH释放量,LDH释放量与阴性对照HB101(5.02%)相似。说明除了CF74,其余的弗氏枸橼酸杆菌不具有细胞毒性。CF74具有和EAEC042一样的聚集性黏附类型,并且 CF74引起的LDH释放率明显高于CF72、2348/69和HB101(P0.01)而低于EAEC17-2。结论 作为潜在的致病菌,CF74具有强的黏附性和细胞毒性。     

Citrobacter sepsis in infants

A study of blood cultures from 320 cases of neonatal sepsis showed 136 (42.5%) to be positive for bacterial growth; of these 82 (60.29%) isolates being gram negative bacilli. Citrobacter was the commonest gram negative bacilli isolated. Other commonly isolated gram negative organisms were Pseudomonas, Klebsiella, Salmonella typhimurium, Acinetobacter and Escherichia coli. Antibiotics susceptibility pattern revealed the isolates to be resistant to commonly used antibiotics.     

Citrobacter freundii septic arthritis

Septic arthritis in an 8 month old infant due to Citrobacter freundii was treated successfully with a third generation cephalosporin. Infections due to Citrobacter are uncommon in this age group and are almost unknown as a cause of septic arthritis.     

Long-Term Outcome of Neonatal Citrobacter koseri (diverus) Meningitis Treated with Imipenem/Meropenem and Surgical Drainage

Neonatal Citrobacter koseri (diversus) meningitis is often complicated by the formation of brain abscesses and has a poor neurological outcome with seizures, mental retardation and paresis as sequelae in 50% of the cases. As there is emerging resistance to ampicillin, gentamicin and third-generation cephalosporins, we attempted to treat this infection with carbapenems. Carbapenems in combination with cefotaxime and surgical drainage may play an important role in treating C. koseri meningitis. Received: September 6, 2000 · Revision accepted: June 24, 2001     

CSF Interleukin-6 in Neonatal <Emphasis Type="Italic">Citrobacter</Emphasis> Ventriculitis after Meningitis

Summary An infant with neonatal severe Citrobacter koseri (formerly Citrobacter diversus) meningoencephalitis developed necrosis with multicystic regression of both hemispheres. The ventriculitis persisted over months in spite of antibiotic therapy. The treatment succeeded with cefotaxime in a high dose (300 mg/kg/day) without surgical intervention. The infant had been previously treated with cefotaxime (200 mg/kg/day) over 5 weeks. High levels of CSF interleukin-6 (IL-6) permitted to attribute persisting CSF pleocytosis in spite of sterile CSF cultures to chronic infection and not to reminiscence of brain necrosis. This report reveals two main points. On the one hand, the importance of therapy monitoring with IL-6 in CSF for the consequent treatment of Citrobacter meningitis and on the other hand, high-dose cefotaxime (300 mg/kg/day) treatment of Citrobacter ventriculitis, which succeeded without surgical intervention. Received: October 2, 1999 · Revision accepted: February 28, 2000     

弗氏枸橼酸杆菌TaqMan实时荧光定量-聚合酶链反应检测方法的建立

目的 建立针对弗氏枸橼酸杆菌的TaqMan实时荧光定量-聚合酶链反应(real time-PCR)检测方法。 方法 针对弗氏枸橼酸杆菌的特有序列设计引物和TaqMan探针,扩增目的基因建立标准曲线,确定检测方法的灵敏度;对20种其他肠道致病菌及院内感染中常见的致病菌进行检测,评价该检测方法的特异性;使用牛奶模拟标本评价方法在实际检测工作中应用性。 结果 TaqMan real time-PCR检测方法对弗氏枸橼酸杆菌重组质粒的检测灵敏度为1.0101拷贝／反应体系;该检测方法在检测30种其他肠道致病菌及院内感染中常见的致病菌时未出现特异性扩增。该检测方法对牛奶模拟样本中弗氏枸橼酸杆菌检测下限为1.0102cfu/ml的菌量;通过对1.0107、1.0105和1.0103三个浓度质粒标准品的重复检测,确定本方法的组内变异系数为1.90%~3.91%;组间变异系数为1.52%~1.69%。 结论 本研究建立的TaqMan real time-PCR检测方法可作为检测弗氏枸橼酸杆菌灵敏、特异、快速的方法。