Biochemical and serological investigations on clinical isolates of klebsiella

A series of 925 clinical isolates of klebsiella was examined by serological and biochemical typing. To perform serological typing (capsular swelling) 77 capsular antisera were prepared, tested against the type strains and grouped in 13 pools. With this serotyping method 80% of the cultures were typable and 63 distinct types could be recognized. All strains were typable biochemically by means of the numerical coding system of the API-20E system supplemented by digits derived from 15 additional conventional biochemical tests. With the API-20E system 24 different biotypes could be distinguished whereas the combination of API-20E and the 15 additional tests produced 93 biotypes. Maximum discrimination of strains was achieved by the combination of serological and biochemical typing (256 bioserotypes). The reproducibility, typability and discriminating power of the biotyping system was not inferior to serotyping. For epidemiological purposes biotyping can replace serotyping of Klebsiella species, especially in laboratories less well equipped.     

Biochemical and serological investigations on clinical isolates of klebsiella.

A series of 925 clinical isolates of klebsiella was examined by serological and biochemical typing. To perform serological typing (capsular swelling) 77 capsular antisera were prepared, tested against the type strains and grouped in 13 pools. With this serotyping method 80% of the cultures were typable and 63 distinct types could be recognized. All strains were typable biochemically by means of the numerical coding system of the API-20E system supplemented by digits derived from 15 additional conventional biochemical tests. With the API-20E system 24 different biotypes could be distinguished whereas the combination of API-20E and the 15 additional tests produced 93 biotypes. Maximum discrimination of strains was achieved by the combination of serological and biochemical typing (256 bioserotypes). The reproducibility, typability and discriminating power of the biotyping system was not inferior to serotyping. For epidemiological purposes biotyping can replace serotyping of Klebsiella species, especially in laboratories less well equipped.     

The development and assessment of a bacteriocin typing method for Klebsiella.

Klebsiellas are generally typed by the method of capsular serotyping but, although this is a reliable method, it is time consuming, requires the production of a large number of antisera and is not generally available. For this reason another method for typing klebsiellas was sought. A bacteriocin typing method involving mitomycin C induction was developed and the cultural conditions giving optimum klebecin production and the best methods of testing the sensitivity of the organisms to klebecins were determined. Of 190 klebsiella strains screened for bacteriocinogeny, only 68 (35.8%) produced klebecin and after calculation of similarity values by computer analysis, a typing set of 15 producers was selected. This typing set allowed over 96% of klebsiella strains to be typed and tests of the reproducibility of the method and the variability of typing patterns in natural populations of klebsiella indicated that results of acceptable accuracy could be obtained, while retaining good discrimination if two or more differences were required between patterns before they were regarded as distinct. A complete set of capsular antisera were prepared, enabling the results obtained from klebecin typing to be compared with those from serotyping. There was generally close agreement between the results from the two typing methods and greater discrimination was obtained between similar strains when the two methods were combined. Klebecin typing and serotyping revealed relationships between strains from five outbreaks of infection, and strains of the same serotype from different hospitals could frequently be distinguished by their klebecin typing patterns.     

Prevalence of serotypes of Xanthomonas maltophilia from world-wide sources.

Since its development in 1988, a serologic typing scheme for Xanthomonas maltophilia, based on 31 O antigens, has been successfully used to serotype isolates involved in nosocomial outbreaks in the United States. To determine if this serotyping scheme would be useful in typing X. maltophilia isolates from world-wide sources, we obtained additional isolates from 10 countries; of 900 isolates tested, 795 (88.3%) were typable. In order of predominance, the three most common serotypes were 10, 3 and 19. These three serotypes were most frequently associated with respiratory and blood isolates. This serotyping system is useful as an epidemiologic screening method for universal typing of outbreaks of X. maltophilia infections.     

A群脑膜炎奈瑟氏菌脂多糖抗原血清学分型的流行病学意义

从江西等省收集了A群脑膜炎奈瑟氏菌324株,应用我们所报道的分型方法可以将96.91%的菌株分成三个主要的脂多糖血清型。不同地区所收集的A群菌株脂多糖血清型的地区分布是不同的,病人与其密切接触者的菌株具有相同的脂多糖血清型,L₁₀型菌株的致病力较强,可以引起流脑流行。本文所述的分型方法操作简便,分型率高。因此,作者认为A群菌株脂多糖血清学分型具有一定的流行病学意义,此分型方法很适于流行病学调查。     

Electrophoretic typing of Enterobacter cloacae with a limited set of enzyme stains

Hospital isolates of Enterobacter cloacae were analysed by polyacrylamide gel electrophoresis for enzyme polymorphism and the results were compared with established serotyping, phage typing and biotyping techniques. Initially, the diversity of electromorphs of 13 enzymes was determined on a representative set of 62 distinct strains. Two broad clusters of strains were found in the species, and analysis by serotype suggested a limited diversity within the most frequent O serotypes. A subset of three enzymes, lactate dehydrogenase, 6-phosphogluconate dehydrogenase, glutamate dehydrogenase and an unidentified marker, were selected and used to type groups of hospital isolates. There was good general agreement between the two systems, although the enzyme method failed to distinguish between some strains with the same serotype. This method provided useful epidemiological information and, in the absence of established typing systems, it is a practical approach to subdividing the species.     

铜绿假单胞菌医院感染与环境因素相关性研究

目的了解铜绿假单胞菌(PA)在医院感染及环境监测中的分布,探讨二者的关系。方法按常规方法对某院2006年6月-2009年6月各类临床标本进行细菌培养与分离,采用VITEK32全自动微生物鉴定仪进行菌株鉴定。PA血清分型采用日本生研株氏会社分型血清进行。结果196株临床分离的PA血清分型率为90.82%（178株）,以G（26.02%）、E（15.31%）、F（14.29%）、B（10.21%）、H（9.69%）、I（7.14%）型为主,未发现的血清型有A、J和K型;25株环境分离的PA血清分型率为96.00%（24株）,以G（32.00%）、F（24.00%）、B（16.00%）、E（12.00%）型为主。结论从患者标本与环境中分离的PA菌株具有相似的血清型,表明其具有一定相关性;菌株血清分型结果可在一定条件下将细菌检验工作与医院感染监测工作有效地结合起来, 用于临床流行病学调查。     

2011-2012年杭州市肠道沙门菌临床分离株的分子型别分析

目的研究2011-2012年杭州市肠道沙门菌临床分离株的型别,了解本地菌株分子流行病学特征。方法对66株肠道沙门菌临床分离株进行血清分型和多位点序列分型(MLST)。对其中主要血清型:鼠伤寒、甲型副伤寒、萨雷甲尼和肠炎沙门菌菌株进行脉冲场凝胶电泳(PFGE)分型。结果分布于21个血清型的66株沙门菌分成26个ST型别。发现一株纽波特沙门菌为新型ST1690。菌株血清型与MLST型别数据库中所对应的血清型符合率为100.00%。9株甲型副伤寒沙门菌的PFGE带型完全一致(P7型),与先前杭州流行菌株有差异(P1-P6型)。6株肠炎沙门菌分成4个PFGE型,型间最小相似性为92.70%。13株鼠伤寒沙门菌分为11个PFGE型,型间最小相似性为71.70%。7株萨雷甲尼沙门菌分成4个PFGE型别,型间最小相似性为91.00%。结论近年杭州腹泻病人中流行的肠道沙门菌菌株主要血清型为鼠伤寒、甲型副伤寒、萨雷甲尼和肠炎等。甲型副伤寒沙门菌菌株在杭州出现了新PFGE型别。MLST数据可以对沙门菌血清学鉴定提供一定的帮助。     

肺炎链球菌PCR分型技术的建立与应用

目的 建立肺炎链球菌血清型分型的PCR简便方法 ,初步了解肺炎链球菌血清型/群的分布状况.方法 设计合成12种肺炎链球菌血清型/群特异性引物,优化不同血清型/群引物FCR条件,并检测最佳反应浓度、灵敏性以及特异性;初步应用于肺炎链球菌菌株的血清型/群检测.结果引物浓度优化后,12种肺炎链球菌血清型/群特异引物呈现较好的特异性与敏感性;对119株肺炎链球菌菌株进行PCR分型检测,其中113株可分为9个血清型/群(3、5、6A/B、9A/V、14、18、19A、19F、23F),6株未分群.结论 初步建立了12种血清型/群肺炎链球菌PCR分型技术,可用于鉴别人群中主要流行的肺炎链球菌血清型/群.     

Phage typing of Campylobacter jejuni and Campylobacter coli and its use as an adjunct to serotyping.

Campylobacter is the most commonly reported cause of gastro-intestinal infection in England and Wales, with over 50,000 reported cases in 1997. The majority of human campylobacter isolates in England and Wales are C. jejuni (c. 90%) with most of the remainder being C. coli. We describe the use of phage typing as an extension to serotyping for more detailed characterization within these two species. The scheme was piloted during a study of 2407 C. jejuni and 182 C. coli strains isolated in Wales between April 1996 and March 1997. Fifty-seven C. jejuni phage types were identified, with the ten most prevalent phage types accounting for 60% of isolates tested; 16% of isolates were untypable. The most common phage type was PT 1 which represented c. 20% of isolates. A further 7% of isolates reacted with the phages but did not conform to a designated type (RDNC). Only 12 phage types were identified among C. coli, with the two most common types, PT 2 and PT 7 accounting for 75.2% of isolates. When used in conjunction with serotyping, the ability of phage typing to identify between 6 and 29 subtypes within each of the predominant HS types has enabled a further level of discrimination to be achieved that enhances the epidemiological typing of C. jejuni and C. coli.     

Comparison of SDS-PAGE protein patterns with other typing methods for investigating the epidemiology of 'Klebsiella aerogenes'

Twenty-four cultures comprising 20 clinical isolates of 'Klebsiella aerogenes' from two hospitals, a reference strain of 'K. aerogenes' and the type strains of three other Klebsiella species, were characterized by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of whole-cell proteins. The protein patterns were highly reproducible and were used as the basis of a numerical analysis which divided the clinical isolates into 12 protein types. Comparison with established typing methods indicated that the level of discrimination of SDS-PAGE was similar to that achieved with conventional typing methods but the strains were grouped differently. Protein typing subdivided five serotype K3 isolates that could also be distinguished by phage typing. Conversely, three strains of protein type 11 were clearly distinguishable by both serotyping and phage typing. We conclude that high-resolution SDS-PAGE of proteins provides an effective adjunct to other methods for typing isolates of 'K. aerogenes'.     

Serotyping of Streptococcus pneumoniae by agglutination assays: a cost-effective technique for developing countries.

There is a need for additional data on the distribution of pneumococcal serotypes in developing countries. We report the use of a coagglutination (COA) and a latex agglutination (LA) test for serotyping Streptococcus pneumoniae which were evaluated using 114 clinical isolates in Vellore, India. In tests to serotype 30 fresh isolates of pneumococci from meningitis (8 isolates), bacteraemia/septicaemia (21 isolates) and peritonitis (1 isolate) cases, there was complete concordance among the three methods. An additional 20 isolates (11 from cerebrospinal fluid and 9 from blood cultures) were serotyped using both LA and COA, with full agreement between the results. With a further 30 isolates, there was 93% concordance for the COA types with serotypes assigned by a WHO reference laboratory. The COA and LA serotyping results were equivalent in accuracy to those obtained using quellung serotyping. Both these agglutination tests are rapid, valid, and relatively cheap, and with appropriate validation by reference laboratories they could be more widely used in developing countries to obtain local and regional data on pneumococcal serotype distribution.     

Epidemiological analysis of Pseudomonas aeruginosa strains isolated from a selected patient population in Brno, Czech Republic.

In the 1996/97 period, 1,413 Pseudomonas aeruginosa (PA) strains were isolated from 843 patients of the Brno teaching hospitals of St. Anne and Bohunice together with small groups from other hospitals. In the same period, 203 PA strains, used as controls, were isolated from 187 patients treated outside hospitals. Statistical evaluation was based on 1,023 hospital isolates and 189 control strains. A total of 16 isolates were recovered from the hospital environments and two from therapeutic swimming pools. The epidemiological analysis of these PA strains was based on pyocin typing, serological typing and phage typing. The most frequently occurring pyocin types amongst our strains fell into 8 pyocin-type groups. The prevailing groups differed significantly between the hospital patient and control groups. Similarly, serological typing identified differences in the predominant serotypes between hospital and control patients. The phage typing method revealed that the control PA strains were significantly more sensitive to 21 polyvalent bacteriophages used than the hospital isolates. In relation to pyocin and serological typing, strains isolated from the hospital environment showed characteristics similar to those of the PA strains isolated from hospital patients. Our results indicate that the majority of strain isolated from hospitalised patients had their origin from human or inanimate contacts in the hospitals.     

Restriction endonuclease analysis of chromosomal DNA from Listeria monocytogenes strains

Restriction endonuclease analysis of chromosomal DNA was applied to thirteen Listeria monocytogenes strains alongside the more conventional typing methods of serotyping and phage typing. The organisms were isolated from cases of sporadic listeriosis (nine strains); from an occasional nosocomial cluster (two strains); and from food samples (two strains).Purified DNAs were digested with EcoRI restriction endonuclease, and restriction fragments separated by electrophoresis. Restriction patterns correlated well with phage patterns, but also allowed typing of the phage-untypable strains.DNA fingerprinting appears to be a potentially helpful tool for epidemiological investigations of listeric infections, particularly when phage typing fails to determine the identity or diversity of the isolates.     

A study of enterotoxigenic Escherichia coli, serogroup 0126, by bacterial restriction endonuclease DNA analysis (BRENDA).

Sixteen isolates of Escherichia coli were subjected to bacterial restriction endonuclease DNA analysis (BRENDA). Nine of these isolates were from an outbreak of human diarrhoea and produced stable toxin, the remaining seven were non-toxigenic strains from animal and human sources. The isolates from the outbreak produced indistinguishable DNA electrophoretic patterns in spite of their assignment to seven different H serotypes. Their BRENDA patterns were markedly different from the other isolates examined. These results support the epidemiological evidence that a single-strain outbreak had occurred, and they cast doubt on the value of H typing for this particular investigation.     

A study of enterotoxigenic Escherichia coli, serogroup 0126, by bacterial restriction endonuclease DNA analysis (BRENDA)

Sixteen isolates of Escherichia coli were subjected to bacterial restriction endonuclease DNA analysis (BRENDA). Nine of these isolates were from an outbreak of human diarrhoea and produced stable toxin, the remaining seven were non-toxigenic strains from animal and human sources. The isolates from the outbreak produced indistinguishable DNA electrophoretic patterns in spite of their assignment to seven different H serotypes. Their BRENDA patterns were markedly different from the other isolates examined. These results support the epidemiological evidence that a single-strain outbreak had occurred, and they cast doubt on the value of H typing for this particular investigation.     

留置导尿患者医院感染铜绿假单胞菌的分子流行病学研究

目的探索留置导尿患者医院感染铜绿假单胞菌（Ｐａ）的感染途径和传播机制。方法从患者小便、脓液、痰液和患者相关环境公用拖帕和洗涤池中共分离出Ｐａ５１株，应用血清学、细菌素、质粒图谱、质粒限制性内切酶图谱、外膜蛋白图谱等方法进行了研究。结果５１株Ｐａ的血清学分型率为８０．４％，细菌素分型率为７７．１％，质粒携带率为６８．６％，呈４种流行模式；来源不同的Ａ、Ｂ、Ｃ三型质粒代表株经用ＥｃｏＲⅠ和ＨｉｎｄⅢ酶切，呈现相同限制性内切酶图谱。９株不同质粒图谱模式菌株，得到两种不同类型外膜蛋白图谱。结论患者与患者之间通过床头柜、床单、导尿管等为媒介，相互交叉感染是导致Ｐａ医院感染的重要因素；一种血清型的细菌可能被分成几种菌素型，同种菌素型也不一定对应于一种血清型；同种血清型的菌株可用质粒图谱分成几种亚型；Ｐａ的外膜蛋白图谱呈高度相似性，图谱模式同血清型无明显联系     

空肠/结肠弯曲菌的血清学分型

按Penner血清分型方法,应用被动血凝试验对349株空肠/结肠弯曲菌进行了分型,其中病人287株,可分型208株(72.5%);健康带菌者17株,可分型11株(64.7%);动物45株,可分型32株(71.1%)。说明Penner血清分型法在我国基本适用,但我国还有新的血清型存在。可分型的菌株共达57个不同的血清型,与国外集中于2、4和3型的报道不一致。从动物菌株的血清分型提示鸡与人的关系比较密切,可能是人类空肠弯曲菌肠炎的主要传染源之一。     

云南省1997-2000年及2004年非脊髓灰质炎肠道病毒分子生物学及流行特征分析

目的描述云南省1997-2000年及2004年5年的肠道病毒（EV）分离状况及型别特征。方法5年在急性迟缓性麻痹病例中共检测到210株非脊髓灰质炎（脊灰）肠道病毒（NPEVs）,其中12株经血清学鉴定为腺病毒。剩余198株经基因测序定型,即病毒VP1区基因序列转变为氨基酸序列后与标准株进行比较。结果经分子生物学定型：人类EV-A组5株（5个血清型）、EV-B组158株（34个血清型）、EV-C组32株（6个血清型）、未分离到EV-D组病毒。在急性迟缓性麻痹病例监测中,210个分离株,EV-B组病毒占75．2%,为主要型别;EV-C组占12．2%,腺病毒占5．7%,EV-A组占2．4%。结论云南省EV的流行中,以EV-B组较多。