Characterization of class 1 integrons and antimicrobial resistance in CTX-M-3-producing Serratia marcescens isolates from southern Taiwan

The objective of this study was to characterize the gene cassettes of class 1 integrons and antimicrobial resistance among CTX-M-3-producing Serratia marcescens isolates from different specimens in southern Taiwan. One hundred and twenty-two isolates (70.5%) of 173 CTX-M-3-producing S. marcescens isolates were positive for class 1 integrons, including 53.3% of blood isolates, 94.1% of urine isolates, and 87.2% of sputum isolates. No class 2 or class 3 integrons were detected in this study. By PCR with primers 5'-CS and 3'-CS for the amplification of gene cassettes regions, amplicons ranging from 0.7 to 3.0 kb in length were found in 108 (88.5%) of the 122 class 1 integron-containing isolates of CTX-M-3-producing S. marcescens isolates. Ten different types by pattern of amplicons for class 1 integrons were obtained. The Type I amplicon (46.3%) harbors two different class 1 integrons containing the gene cassette of aadA2 and aadB-catB3, respectively, and was most prevalent in the gene cassette region-positive S. marcescens isolates, followed by the Type II amplicon, which harbors one class 1 integron containing the gene cassette dfrA12-orfF-aadA2 (28.7%). Most of the S. marcescens isolates (66.7%, 8/12) harboring three different class 1 integrons (Type IV amplicon) were found in blood isolates. Class 1 integrons were conjugally transferred to recipients in 92.0% of S. marcescens harboring two different class 1 integrons containing the gene cassettes aadA2 and aadB-catB3, respectively. The transfer rate of class 1 integron carrying dfrA12-orfF-aadA2 was detected in 77.4% of S. marcescens isolates. The results showed that all those isolates with conjugative transfer of integrons carried their class 1 integrons on the conjugative plasmids.     

Instability of antibiotic resistance in a strain of Staphylococcus epidermidis isolated from an outbreak of prosthetic valve endocarditis

Plasmid profiles, phage typing, antibiograms, and biotyping were used to characterize Staphylococcus epidermidis isolated from multiple cultures of blood of four patients with prosthetic valve endocarditis. Epidemiological evidence implicated a common source for these infections. Of 20 clinically significant isolates, 14 exhibited variations from the prototype pattern of multiple resistance to five antibiotics. All isolates tested appeared to be the same strain by phage typing. Of 18 isolates available for plasmid analysis, 10 contained six plasmids of identical size, whereas eight differed from the prototype profile in the loss of one to three plasmids. Loss of resistance to gentamicin, chloramphenicol, erythromycin, and clindamycin but not to methicillin was associated with the loss of specific plasmids. Because antibiotic resistance in this strain of S. epidermidis was unstable, the use of antibiograms alone was not a reliable means of evaluating the relatedness of these multiple isolates.     

Inhibition of Salmonella ferlac by enterobacteria under in-vitro conditions.

Interactions of Proteus morganii, Proteus mirabilis, Proteus sp. Klebsiella oxaenae and Serratia marcescens isolated from vegetable salads of mass feeding systems with Salmonella ferlac (a new subgenus VI of Salmonella) isolated from a hostel cook's hands and lizard droppings were recorded following in-vitro nephelometric analysis. Nephelometric analysis revealed inhibition of S. ferlac by all the tested isolates from fifth hour of mixed culture interaction. K. oxaenae was the strong inhibitor.     

Pathogen occurrence and antimicrobial susceptibility of urinary tract infection cases during a 20-year period (1983-2002) at a single institution in Japan

Urinary tract infections are one of the most common infectious diseases diagnosed in outpatients as well as in hospitalized patients. Recently, urinary tract infections have become more complicated and difficult to treat. Therefore, the present study analyzed the occurrence and antimicrobial susceptibility of uropathogens isolated at Kobe University Hospital between 1983 and 2002. This study was performed with three patient groups: urology inpatients, urology outpatients, and inpatients of other departments. During the 20-year study period, we studied 15,925 urine isolates obtained from those patients who were diagnosed with urinary tract infection. Overall, Enterococcus faecalis was the most frequently isolated pathogen, followed by Pseudomonas aeruginosa and Escherichia coli. The frequency of Staphylococcus aureus increased over time, corresponding to an increase in the occurrence of methicillin-resistant S. aureus (MRSA). In addition, the rate of isolation of Serratia marcescens also increased over time, especially among patients with urinary tract catheters. Our results demonstrate that the uropathogens isolated at a single institution have shown a trend of increasing resistance to various classes of antimicrobial agents. In addition, serious problems should be anticipated in the treatment of multidrug-resistant P. aeruginosa, fluoroquinolone-resistant E. coli, and arbekacin-resistant MRSA.     

Serratia marcescens endocarditis: a regional illness associated with intravenous drug abuse.

From 1969 to 1974, 19 cases of Serratia marcescens endocarditis were observed in the San Francisco Bay Area. Seventeen patients were intravenous drug users, and Serratia caused 14% of all addict-associated endocarditis in San Francisco. Serratia strains were nonpigmented and had typical antibiotic sensitivities, except that 9 of the isolates exhibited colonial variation, with each variant having different antibiotic sensitivities. Aortic or mitral valves were involved in 13 patients, and heart failure developed in 9 of these. Twelve patients had embolic episodes to brain, iliofemoral arteries, or lung. Five of 6 patients with tricuspid valvulitis were cured by antibiotics either with (1) or without excision of the valve. All 12 patients with aortic or mitral valvulitis treated medically died; 11 had unremitting sepsis. Aortic valve replacement and antibiotics were effective in 1. Gentamicin combined with either carbenicillin or chloramphenicol was the most effective treatment regimen.     

Serratia marcescens bacteremia after carotid endarterectomy and coronary artery bypass grafting.

Serratia Marcescens is a common, water-borne hospital colonizer. Respiratory secretions, wounds, and urine are frequently recognized areas of Serratia colonization. Serratia bacteremias usually occur nosocomially and are associated with high mortality and morbidity rates. Serratia bacteremias may be primary or secondary from an identifiable source. Hospital-acquired S marcescens bacteremias have no known source in half of the cases. We present a case of nosocomial primary S marcescens bacteremia in a surgical patient successfully treated with levofloxacin.     

Survey on clinical isolates from 13 hospitals in Akita Prefecture--changes in frequency and susceptibility of isolates by scale of hospital. Survey Group for Clinical Isolates, Chemotherapy Research Committee of Akita Prefecture

Isolates from various clinical materials in 13 hospitals in Akita prefecture and their drug susceptibility were investigated by the Chemotherapy Research Committee of Akita Prefecture during the period from Dec., 1987 to Feb., 1988. The results were as follows: 1. The total number of isolates was 8,387, including Staphylococcus aureus (18.9%), Pseudomonas aeruginosa (10.9%), Staphylococcus epidermidis (7.3%) and Enterococcus faecalis (6.6%). S, aureus and P. aeruginosa were detected more frequently in the larger hospitals. 2. The detection frequency of S. aureus from the sputum, throat swab and pus exudate was also very high. There was a diversity in isolates from the urine and the frequency of Escherichia coli was low. More than half of the isolates from the blood were S. epidermidis and S. aureus. Many kinds of bacteria were detected from pleural fluid and ascites, but the isolate showed no particular tendency. 3. The susceptibility of S. aureus to oxacillin were variable in hospitals, and the susceptibility to cefazolin were even lower. Low susceptibility were also seen with norfloxacin. S. aureus showed the highest susceptibility to minocycline. The susceptibility was lower for inpatients than for outpatients. P. aeruginosa showed low susceptibility to cefsulodin. The number of ampicillin-resistant Haemophilus influenzae isolates tended to decrease. Enterobacter cloacae showed a low susceptibility for cephems. Serratia marcescens showed low susceptibility to many drugs. Based on the above results, we concluded that attention should be paid to S. aureus, P. aeruginosa and Enterobacter in clinical practice.     

Community acquired sepsis by Serratia rubidaea

A 48-year-old male who had a past history of alcoholic pancreatitis and diabetes mellitus was admitted to our hospital due to chills and vomiting, on August 13, 1998. His body temperature was 38.0 degrees C, and he had the disturbance of consciousness, tachypnea, tachycardia and hepatomegaly with tenderness. Laboratory findings showed highly inflammatory reactions, DIC and hepatorenal dysfunction. Abdominal CT and US revealed multiple liver abscess with portal vein thrombus. Serratia rubidaea was detected in the blood culture. SBT/CPZ and TOB were administered and he recovered. This is a rare case of Serratia rubidaea sepsis. It is also necessary to pay attention to Serratia infections as well as S. marcescens.     

An outbreak of Serratia marcescens associated with the anesthetic agent propofol

BACKGROUND: In October 1999, 7 patients with postoperative infections caused by Serratia marcescens were identified at a community hospital in Ontario, Canada. We describe the investigation of this outbreak. METHODS: We undertook a case-control study to determine risk factors associated with infection. Case subjects consisted of patients who had undergone surgery and acquired bacteremia or wound infections that, when cultured, grew S marcescens. Control subjects were selected from the cohort of patients who underwent surgery at the same hospital during the outbreak period. Chart reviews were conducted for case and control subjects. Environmental samples were taken from medications and liquids in the operating rooms and from one health care professional who was involved in all the cases. S marcescens isolates were forwarded to a reference laboratory for pulsed field gel electrophoresis. RESULTS: We identified 7 case subjects and 29 control subjects. Five patients had bacteremia and 2 patients had wound infections. Two patients with bacteremia died. All patients with bacteremia or wound infections were exposed to a single anesthetist (anesthetist A) and were administered the anesthetic medication propofol. These patients were more than 40 times more likely to have had anesthetist A administer their anesthetic (OR 41.6, 95% CI 3.6-1120) and 22 times more likely to have received propofol (OR 22, 95% CI 2.1-550) than were control subjects. None of the environmental samples or cultures from anesthetist A were positive for S marcescens. Six of the 7 human isolates had an identical pulsed field gel electrophoresis pattern, and the seventh was untypable. CONCLUSIONS: This outbreak of postoperative infections was very strongly linked to the use of propofol by one anesthetist. Health care professionals must follow strict aseptic techniques when using propofol and should review these techniques regularly.     

Isolation of C. diphtheriae gravis in Leeds

Four isolations of Corynebacterium diphtheriae gravis were made in Leeds over three weeks in the early part of 1980. The first three isolations were made independently and the fourth was a close family contact of the third. Only the first isolate was shown to be toxigenic and could be distinguished from the others by phage typing but all were indistinguishable otherwise by biotyping and bacteriocin typing. Detailed epidemiological investigation failed to establish any connection among the three incidents, or any other positive contacts. Five months later, C. diphtheriae gravis was isolated from a five-month-old infant and from 17 other individuals during contact screening. All 18 isolates from this episode were shown to be non-toxigenic and were indistinguishable by biotyping and bacteriocin typing.     

Pseudooutbreak of Pantoea species bacteremia associated with contaminated cotton pledgets

A total of 22 isolates of Pantoea strains, unusual causative agents of clinical infection, was isolated from blood cultures from 9 patients and 1 ear swab from 1 of the patients within a period of 1 month in a tertiary-care hospital. Pseudooutbreak was suspected because specimens were collected from a limited number of places and the patients did not show consistent signs or symptoms of bacterial sepsis. Enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR) and partial 16S ribosomal DNA sequencing were performed to determine the clonal relationship among the isolates. Screening environmental cultures revealed that cotton pledgets were contaminated with Pantoea species. Molecular typing suggested that 2 different clones of Pantoea strains were responsible for the pseudooutbreak. Cotton materials may be a possible source of Pantoea pseudooutbreak. Molecular typing is useful for investigating epidemics and identifying unusual clinical isolates.     

Molecular analysis of R-factors from multiresistant nosocomial isolates

During an epidemic of infections at the Seattle Veterans Hospital, Washington, due to a multiresistant strain of Serratia marcencens, other enteric species were isolated that had antibiograms nearly identical to those of the epidemic S. marcescens. In 11 instances, these multiresistant species were isolated from specimens that also contained the epidemic serratia strain. All isolates of the epidemic serratia strain contained a conjugative 45-megadalton R-factor (pLST1000) coding for intermediate resistance to three amino-glycosides (minimal inhibitory concentrations, 4--8 micrograms/ml) and high-level resistance to ampicillin, carbenicillin, cephalothin, streptomycin, and sulfonamide. With the use of agarose gel electrophoresis and restriction endonuclease cleavage patterns after digestion with EcoRI, BamH1, and HindIII, it was determined that eight different enteric strains of six different species isolated from the patients contained an R-factor that was molecularly identical to the one isolated from the epidemic strain of S. marcescens. Thus, the epidemic of multiresistant infections at this hospital was caused both by the spread of an epidemic strain and an "epidemic plasmid." The molecular characteristics of pLST1000 appear to be different from previously described multiresistant plasmids.     

河南省26例甲型副伤寒沙门菌聚集性病例的病原学研究及溯源分析

目的 分析2015年3-7月份河南省登封市分离自临床诊断为副伤寒聚集性病例的甲型副伤寒(S.Paratyphi A)沙门菌病原学特征及分子流行病学关联。方法 采集副伤寒病例患者的静脉血8~10 mL,双相血培养瓶37 ℃培养4~7 d,沙门菌科玛嘉选择性培养基分离培养,系统生化鉴定,丹麦SSI分型血清进行沙门菌O抗原及H1/2相鞭毛诱导血清凝集试验。根据PulseNet China病原体分子分型网络实验室公布的沙门菌脉冲场凝胶电泳(PFGE)操作指南与美国临床实验室标准化协会(CLSI)沙门菌K-B法药敏测试方案对其进行XbaI/BlnI双酶切PFGE分子分型与聚类分析及8类13种抗生素药敏测试。结果 从29例病人血培养物中共分离到26株甲型副伤寒沙门菌,其经XbaI与BlnI限制性双酶切和PFGE电泳后带型完全一致(PTYA1);药敏测试结果显示24株甲型副伤寒沙门菌耐药表型一致。结论 病原学诊断及PFGE分子分型结果证实了26例甲型副伤寒沙门菌感染病例间可能存在高度的聚集性与分子流行病学关联,为进一步的追踪溯源和调查取证提供了技术支撑。     

Clonal diversity of Salmonella enterica serotype Typhi isolated from patients with typhoid fever in Tehran

In this study, antimicrobial susceptibility test and genetic typing were used to characterize 15 Salmonella enterica serotype Typhi (S. Typhi) isolates recovered from sporadic cases of typhoid fever in Tehran, Iran during 2004. Antimicrobial susceptibility test showed that all isolates were susceptible to 20 antimicrobials examined in this study. Analysis of insertion elements showed that 2 IS200 types with 10 and 11 copies were present. 11 of the 15 isolates were found to possess 10 IS200 elements residing on fragments from 23 to 2.3 kb. Comparison of the RiboPrinter (automated ribotyping) patterns of S. Typhi showed that 60% (9/15) of the isolates belonged to a single ribotype. PCR based random amplified polymorphic DNA analysis (RAPD) and enterobacterial repetitive intergenic consensus (ERIC) and pulsed-field gel electrophresis (PFGE) were also performed. ERIC and RAPD-PCR method showed 2 and 3 genotyping patterns amongst the isolates, respectively. The PFGE typing was carried out by using XbaI restriction enzyme, and 7 restriction patterns were observed. Overall, the molecular typing methods applied in this study showed that the isolated S. Typhi populations were highly polyclonal as shown by PFGE.     

1株粘质沙雷氏菌噬菌体的分离和鉴定

目的 以粘质沙雷氏菌为宿主菌,从河水中分离噬菌体,在体外和蚊虫肠道验证其裂解能力。方法 以粘质沙雷氏菌为宿主菌,在深圳周边河水中分离噬菌体,通过单、双层平板筛选单一的烈性噬菌体;利用噬斑形成实验验证噬菌体的裂解谱;通过饲喂实验验证噬菌体在埃及伊蚊肠道内的裂解作用。结果 从深圳河流污水中成功分离得到一株针对粘质沙雷氏菌的烈性噬菌体SHENZHEN01, 该噬菌体噬斑直径1 mm左右(培养10 h), 边界清楚;对粘质沙雷氏菌Sm01、Baz01具有明显的裂解能力,对其他粘质沙雷氏菌菌株、大肠杆菌、金黄色葡萄球菌、绿脓杆菌无裂解作用;对饲喂埃及伊蚊的粘质沙雷氏菌Sm01仍保持明显的裂解能力。结论 该噬菌体裂解作用具有特异性,而且在蚊虫肠道内仍能保持活性,具有可以用来治疗粘质沙雷氏菌引起的相关疾病的潜在价值。     

Patient factors contributing to the emergence of gentamicin-resistant Serratia marcescens.

One hundred forty nosocomial Serratia marcescens infections (including 76 cases of bacteremia) were identified by prospective surveillance from 1975 through 1977 and retrospective chart review from 1968 through 1974. Thirty-four cases (24 per cent) involved gentamicin-resistant strains. All gentamicin-resistant strains appeared after 1974. Ninety per cent of the patients had undergone surgery, and 88 per cent had received prior antimicrobial therapy. The emergence of gentamicin-resistant S. marcescens paralleled the increase in usage of gentamicin. Prior use of gentamicin for more than two days in an individual patient was a significant risk factor (P = 0.0002) for being infected with a Serratia that was gentamicin-resistant. Other factors which separated gentamicin-resistant Serratia infections from gentamicin-sensitive Serratia infections were (1) urinary site of infection (P = 0.0005), (2) urinary catheter (P = 0.002), (3) endotracheal tube or tracheotomy (P = 0.03) and (4) increasing duration of hospitalization (P less than 0.05). Thirty-three of 34 (97 per cent) patients with gentamicin-resistant strains had urinary catheters. Specific measures to control infection were effective in decreasing the incidence of infections caused by gentamicin-resistant Serratia.     

IMP-1 type metalo-beta-lactamase producing Serratia marcescens strains isolated from blood culture between 1991 to 2000

Infection caused by metallo beta-lactamase (MBL)-producing bacteria have been increasingly reported in Japan in recent years. We investigated the prevalence, clinical backgrounds and molecular epidemiology of MBL-producing Serratia marcescens strains isolated from blood cultures at our university hospital between 1991 and 2000. Forty-three S. marcescens strains were isolated in the period, and the incidence reached about 2% total bacteria detection in 1998 and 1999. There were 13 ceftazidime-resistant strains (31%), and five of them produced MBL. MICs of imipenem (IPM) were 4-16 mg/ml, of which one strain was susceptible to IPM. Of the five MBL-producers, four were obtained from a tertiary emergency ward, the underlying diseases being either serious trauma or cerebrovascular diseases. The other was isolated from a patient who underwent kidney transplantation. S. marcescens was no longer isolated from patients after administration of aztreonam (AZT), implying that AZT was clinically effective. When analyzed genetically using the AP-PCR technique, the patterns were identical among strains isolated in 1996, 1997 and 1998 and those isolated in 1999 and 2000 respectively, suggesting that the same strains may have inhabited the hospital wards for prolonged periods. Countermeasures against nosocomial infection was undertaken thereafter, resulting in reduction of isolation frequency. It cannot be excluded that the resistant bacteria spread as the amount of carbapenem consumption increased. Prudent use of antibiotics is mandatory to prevent further dissemination of such MBL producers.     

An outbreak of Serratia marcescens in 14 adult cardiac surgical patients associated with 12-lead electrocardiogram bulbs.

Two clusters of Serratia marcescens in 14 adult cardiac surgical patients occurred over 10 months in an 876-bed teaching hospital. The 14 infections that were studied were as follows: one sternal and five leg incisions, five pneumonias, one bacteremia, one urinary tract infection, and one infected internal defibrillator site. The first cluster included four pneumonias, one urinary tract infection, and one bacteremia. Corrective actions were taken based on outbreak data through no source was identified. No further infections occurred during the following 2 months. The second cluster included one sternal and five leg incisions, an infected internal defibrillator incision site, and one pneumonia. Serratia marcescens was isolated from six electrocardiogram rubber welsh bulbs with sensitivities identical to patient isolates that indicated a common source outbreak in at least the second cluster of infections. Disposable electrocardiogram leads were introduced and the problem was resolved. We conclude that reusable electrocardiogram welsh bulbs are a vector for postoperative infections.     

Melioidosis presenting with isolated splenic abscesses: a case report

Splenic abscesses caused by Burkholderia pseudomallei are rarely reported in Taiwan. Here we report a middle-aged man who presented with fever, chills, and general malaise for several days. Abdominal echo revealed isolated splenic abscesses and he received antibiotics treatment according to the initial blood culture result, Serratia marcescens. However, fever did not subside. Then he was referred to our hospital and meropenem was prescribed. Fever subsided 5 days after the beginning of meropenem administration. Repeated fine-needle aspiration of splenic abscesses drained out the pus, which was cultured as B. pseudomallei. He was finally diagnosed as a case of melioidosis based on microbiological evidence. Physicians must take melioidosis into consideration when splenic abscesses are encountered clinically.     

黏质沙雷菌随机扩增多态性DNA法基因分型及意义

目的 探讨黏质沙雷菌（SM）随机扩增多态性DNA（RAPD）法基因分型及意义。方法 以优化的反应体系及单一随机引物AV15对临床分离的109株SM进行RAPD分析并按指纹图上DNA条带数及片段大小绘制基因分型图谱。结果 109株SM共得78种RAPD型。结论 RAPD法可用于SM的基因分型。