OBJECTIVETo characterize the genetic background of multidrug-resistant Acinetobacter baumannii (A. baumannii) from China, and the population structure of this pathogen.

METHODSA previously reported MLST scheme was applied to a collection of 33 multidrug-resistant strains of A. baumannii from China, and the data of all the strains in the A. baumannii MLST database were downloaded for the population structure analysis. The sequence types and clonal complexes were identified, the presence or absence of recombination was analyzed for each MLST locus, and the values of I(A)(S), and recombination/mutation ratio were calculated for the whole strain collection. A phylogenetic tree was constructed using all the allelic profiles in the database.

RESULTSA total of six sequence types were identified from the 33 Chinese strains tested, and 29 of these strains belonged to the CC92 clonal complex. Three (gdhB, gpi, and rpoD) of the seven MLST loci (gltA, gyrB, recA, cpn60, gdhB, gpi, rpoD) had undergone recombination with statistical evidence. For all allele profiles in the MLST database, the I(A)(S) value was 0.155 and the recombination/mutation ratio was 6.083. Sequence types from each clonal complex were grouped closely in the phylogenetic tree, which gave an overview of the microevolution of this pathogen.

CONCLUSIONThe spread of multidrug-resistant A. baumannii in China was closely related to the CC92 clonal complex. A. baumannii had an 'epidemic' population structure, i.e., a superficially clonal structure with high levels of recombination, in which successful epidemic clones arise especially including worldwide dissemination of the CC92 clonal complex to cause a widespread occurrence of multidrug-resistant infections.

Acinetobacter baumannii ; classification ; genetics ; isolation & purification ; Bacterial Typing Techniques ; China ; Cluster Analysis ; DNA, Bacterial ; genetics ; Drug Resistance, Multiple, Bacterial ; Genetic Variation ; Genetics, Population ; Molecular Epidemiology ; Molecular Sequence Data ; Multilocus Sequence Typing ; Phylogeny

OBJECTIVETo analyze molecular and evolution characteristics of Salmonella Paratyphi A isolates from 2000 to 2008, China.

METHODSUsing pulsed-field gel electrophoresis (PFGE) method with SpeI restriction enzyme, and multilocus sequence typing (MLST) method based on housekeeping genes (aroC, thrA, hisD, purE, sucA, dnaN, hemD, adk, and purA), the genomic variations of 118 Salmonella Paratyphi A isolates from 10 regions during 2000 to 2008 were analyzed.

RESULTSUsing PFGE method, 118 Salmonella Paratyphi A isolates were clustered into 32 PFGE patterns, and 5 patterns were predominant (5 isolates or above). However, only 2 MLST types were identified for all isolates with MLST method. Among all Salmonella Paratyphi A isolates, the sequences of housekeeping genes were highly conservative and showed a high degree of cloning.

CONCLUSIONFor Chinese epidemic Salmonella Paratyphi A isolates during 2000 - 2008, MLST method showed low discrimination power and the MLST method should not be applied to outbreak and epidemiological surveillance of Salmonella Paratyphi A. Currently, nationwide paratyphoid fever epidemics is caused by highly clonal isolates in China. As the time changes, these isolates also accumulate sporadic mutations.

Bacterial Typing Techniques ; China ; DNA, Bacterial ; genetics ; Electrophoresis, Gel, Pulsed-Field ; methods ; Humans ; Multilocus Sequence Typing ; Paratyphoid Fever ; epidemiology ; microbiology ; Salmonella paratyphi A ; classification ; genetics ; isolation & purification ; Sequence Analysis, DNA ; Serotyping

Bacterial Typing Techniques ; Leptospira interrogans ; classification ; genetics ; Minisatellite Repeats ; Multilocus Sequence Typing ; methods

Bacterial Typing Techniques ; Campylobacter Infections ; microbiology ; Campylobacter fetus ; classification ; isolation & purification ; Humans ; Multilocus Sequence Typing

OBJECTIVETo study the epidemiological characteristics and molecular phenotypes of Salmonella by pulsed-field gel electrophoresis (PFGE) in Beijing from 2008 to 2009.

METHODSA total of one hundred thirty-seven isolates recovered from the WHO Global Salmonella Surveillance system and entero clinic surveillance system were identified by biochemical tests and serotyping. The related epidemiological informations were also analyzed. The isolates were further typed by PFGE.

RESULTSThe prevalence of Salmonella from 2008 to 2009 showed obvious seasonal character. High incidence occurred from June to September, and 64.1% (84/131) isolates were recovered in this period. Patients of 18 - 40 year-old were 46.1% (58/128) and 80 patients were male and 40 patients were female with the ratio of 1.57:1. These 137 Salmonella isolates belonged to 20 serotypes, including Enteritidis (46.7%, 64/137) and Typhimurium (17.5%, 24/137) as the dominant serotype. In total, 71 PFGE profiles were identified. Four PFGE patterns of S. Enteritidis isolates (JEGX01.CN0001, JEGX01.CN0003, JEGX01.CN0002, JEGX01.CN0019) and S. Typhimurium pattern of JPXX01.CN0001 were dominant patterns.

CONCLUSIONThe prevalence of Salmonella from 2008 to 2009 showed distribution characteristics of sex, age and seasons. The numerous PFGE patterns of Salmonella showed diversity of these isolates and different clones existed in Beijing.

Adolescent ; Adult ; Bacterial Typing Techniques ; China ; epidemiology ; DNA, Bacterial ; isolation & purification ; Electrophoresis, Gel, Pulsed-Field ; Female ; Food Microbiology ; Humans ; Male ; Molecular Typing ; Salmonella ; classification ; genetics ; isolation & purification ; Salmonella Infections ; epidemiology ; microbiology ; Serotyping ; Young Adult

Bacterial Typing Techniques ; Molecular Biology ; Mycobacterium tuberculosis ; classification ; genetics

PURPOSE: The increasing prevalence and global spread of carbapenem-resistant Acinetobacter baumannii (A. baumannii) has become a serious problem. The aim of this study was to investigate molecular and epidemiological characteristics of carbapenem-resistant A. baumannii isolates collected from Korean non-tertiary hospitals. MATERIALS AND METHODS: Thirty six non-duplicated carbapenem-resistant A. baumannii isolates were collected from 17 non-tertiary hospitals in Korea between 2004 and 2006. Isolates were typed by multilocus sequence typing and repetitive-sequence-based PCR (rep-PCR). Detection of genes encoding OXA carbapenemase and their relationship with ISAba1 was performed by PCR. RESULTS: Two clones were prevalent among 36 isolates: ST69 (17 isolates, 47.2%) and ST92 (19 isolates, 52.8%). Rep-PCR patterns were diverse and revealed that all isolates were clustered into eight band patterns. The ISAba1-activated blaOXA-23-like and ISAba1-activated blaOXA-51-like genes were prevalent among the carbapenem-resistant A. baumannii isolates. CONCLUSION: The class D beta-lactamase genes of A. baumannii were distributed nationwide in non-tertiary Korean hospitals.
Acinetobacter Infections/epidemiology/*microbiology ; Acinetobacter baumannii/classification/*genetics ; Anti-Bacterial Agents/therapeutic use ; Bacterial Typing Techniques ; Carbapenems/*therapeutic use ; DNA, Bacterial/analysis ; *Drug Resistance, Bacterial ; Hospitals ; Humans ; Microbial Sensitivity Tests ; Molecular Epidemiology ; Multilocus Sequence Typing ; Polymerase Chain Reaction ; Prevalence ; Republic of Korea ; beta-Lactamases/genetics

OBJECTIVETo identify and characterize the Brucella strains from Guizhou province in 2010-2013.

METHODSA total of 12 strains of Brucella suspicious bacteria were isolated in Guizhou province from 2010 to 2013. Four strains (GZLL3, GZLL4, GZLL11 and SH2) were isolated from goat blood samples and eight strains (SH4, GZZY, GZSQ, GZZA, BR13001, BR13004, BR13005 and BR13006) were isolated from blood samples of patient 12 Brucella suspicious strains were identified and characterized using conventional methods. Brucella genus specific gene BCSP31-based PCR (BCSP31-PCR) was used to identify the genus of Brucella and IS711 insert sequence-based PCR (AMOS-PCR) was applied to identify the species of Brucella strains. Goats and patients originated Brucella strains were comparatively analysed using Pulse-field Gel Electrophoresis (PFGE).

RESULTSBoth of conventional methods and PCR identified the 12 Brucella suspicious strains as B. melitensis biotype 3. BCSP31-PCR identification results showed that a specific DNA bands (223 bp) were detected in all the 12 strains and positive control samples with no DNA band in negative samples. AMOS-PCR amplified a 731 bp-DNA bands in all the 12 strains, with 731 bp, 498 bp and 275 bp in M5, S2 and A19 strains, respectively, and no DNA band was detected in the negative control samples. PFGE analysis showed that 12 Brucella isolates from patients and goats showed consistent PFGE patterns with the digestion of restriction enzyme Xba I.

CONCLUSIONThe epidemic species/type of Brucella in both human and animal in Guizhou province was B. melitensis biotype 3 and goat was the main animal source of infection of brucellosis in Guizhou province.

Animals ; Bacterial Typing Techniques ; Brucella ; classification ; Brucellosis ; epidemiology ; China ; epidemiology ; DNA, Bacterial ; Goats ; Humans ; Molecular Typing ; Polymerase Chain Reaction

OBJECTIVETo evaluate the feasibility of the application of variable-number tandem repeat (VNTR) loci of Salmonella Enteritidis (S. enteritidis) in subtyping mutiple-locus variable-number tandem repeat analysis (MLVA).

METHODSA total of 16 isolates of S.enteritidis from different place and time in China were preliminarily assessed by choosing 11 reported VNTR loci, the loci with single amplified bands were picked to subtype all 104 S. enteritidis isolates. The isolates were also analyzed by pulse field gel electrophoresis (PFGE) to compare the superiority or inferiority of MLVA method and PFGE method.

RESULTSSeven VNTR loci were selected from the preliminary screening to expand the analysis, and the 7 VNTR loci had grouped 104 of S.enteritidis isolates into either 16 MLVA subtypes or 22 PFGE subtypes, with the D value at 0.7222 and 0.7974, respectively. Comparing with the isolates in MLVA subtypes, the isolates in PFGE showed a stronger resolving power. Meanwhile the results in PFGE showed a more disperse frequency distribution than those in MLVA.

CONCLUSIONThese results indicate that some VNTR locus which have shown a good polymorphism internationally, may fail to show polymorphism in China, thereby, more VNTR loci should be included in MLVA and the wide screening may benefit the unity of global laboratorial methods.

Bacterial Typing Techniques ; methods ; Electrophoresis, Gel, Pulsed-Field ; Minisatellite Repeats ; Multilocus Sequence Typing ; methods ; Salmonella enteritidis ; classification ; genetics

OBJECTIVETo investigate the molecular characteristics of phage-type 6b isolates emerging in 1998-2001 cholera epidemics in Sichuan province.

METHODSIsolates were analyzed by phage-typing, pulsed field gel electrophoresis (PFGE) and ompW gene sequencing.

RESULTSAll phage-type 1b and 6b isolates in Sichuan province from 1998 to 2001 were toxigenic. A total of 24 patterns were identified after PFGE analysis, and one predominant pattern consisted of 13 isolates. Several 1b and 6b isolates from Sichuan and isolates of the 1b from other provinces showed the same PFGE pattern. Mutation in ompW gene was found in 6b isolates.

CONCLUSIONV.cholerae O1 6b isolates in Sichuan province from 1998 to 2001 have special genetic markers, and might genetically correlate with contemporaneous 1b isolates.

Bacterial Typing Techniques ; Bacteriophage Typing ; China ; epidemiology ; Cholera ; epidemiology ; microbiology ; DNA, Bacterial ; genetics ; Electrophoresis, Gel, Pulsed-Field ; Genes, Bacterial ; Genotype ; Vibrio cholerae ; classification ; genetics ; isolation & purification