Objective To identify the biotype and analyze the epidemiological characteristics of twentyfour Brurella strains from the primary hospitals in Guangdong Province.Methods The twenty-four Brucella strains,collected from Oct.2009 to Oct.2015,were identified by routine biochemical methods,VITEK 2 COMPACT automatic microbial identification analyzer,16S rRNA gene sequencing and biology phenotype based on serological and bacteriophages lysis test.The etiology was analyzed based on clinical data,biotypes of the isolates and other clinical information.Results All of the twenty-four strains were Gram-negative coccobacilli,including two strains of Brucella suis biotype Ⅱ,four strains of Brucella melitensis biotype Ⅰ and eighteen strains of Brucella melitensis biotype Ⅲ.By GN card of VITEK 2 COMPACT automatic microbial identification analyzer,one strain was mistaken as Bordetella bronchiseptica and two strains were mistaken as Ochrobaetrum anthropi.The 16S rRNA gene sequencing showed they were high homology to Ochrobactrum intermedium and Ochrobaetrum anthropi,which completely excluded the possibility of Bordetella bronchiseptica.Tbe clinical data showed that all of the twenty-four patients were adults with an average age of 49.0 years old,men and women were twelve people respectively,with no significant gender differences and no occupational exposure,which presenting a wide and diverse range of nonspecific clinical signs and symptoms,but brucellosis was not aware of by the physician.Conclusion Brucella melitensis biotype Ⅲ is the main pathogen of brucellosis,with the characteristics of sporadic outbreak and occult infection in the primary hospitals in Guangdong Province.

Objective To investigate the polymorphism of Brucella melitensis biovar 3 ( B.melitensis biovar 3) strains isolated from Guangdong province .Methods PCR assays followed by agar-ose gel electrophoresis and capillary electrophoresis based on the multiple locus variable number of tandem repeats (VNTR) analysis (MLVA) were performed to analyze 43 clinic isolates of B.melitensis biovar 3 strains isolated from clinical patients in Guangdong province .Results MLVA typing showed that the simi-larities of the analyzed locus among 43 strains of Brucella ranged from 68.2%to 100%.32 genotypes identi-fied among the isolates were identical (100%similarity).27 out of 43 strains (62.8%) were single geno-types, while the other 16 strains (37.2%) belonged to 5 other genotypes with 2 to 5 strains in each of them . Conclusion B.melitensis biovar 3 isolates showed polymorphism distribution in Guangdong province as in-dicated by MLVA typing analysis .Single-genotype isolates accounted for 62.8% of all studied strains.No predominant genotype was found among all isolates .

Objective To investigate the etiological characteristics of Streptococcus pyogenes that caused scarlet fever in different periods in Guangdong province.Methods 22 isolates from different periods were analyzed through emm typing,PCR detection for super antigen genes,antibiotic susceptibility test and pulsed-field gel electrophoresis (PFGE).Results All isolates were susceptible to cefotaxim,levofloxacin and penicillin.Streptococcus pyogenes isolated after the year 2000 were 100％ resistant to erythrocin and clindamycin,but the resistant rate for strains isolated before the year 2000 was 9.1％ (1/11).There were 3 emm types indentified from 22 isolates including emm12.0 (59.09％,13/22),emm6.0 (36.36％,8/22) and emm1.0 (4.55％,1/22),which were detected in the isolates from the year 1997 and 2011,from 1978 and 1986,and from 2008,respectively.The positive rates for speA,speB,speC,speF,speG,speH,smeZ,and ssa genes detected by PCR were 54.55％,100％,100％,100％,100％,54.55％,0％,and 86.36％ respectively.Among all strains,95.45％ of the isolates carried 6 superantigen genes simultaneously.Three clusters of 10 PFGE subtypes were identified in 22 isolates.Cluster Ⅰ consisted of all strains from 1997 and one strain from 2011.Cluster Ⅱ consisted of strains isolated from 1978 and 1986.Cluster Ⅲ consisted of nine strains from 2011 and one from 2008.Conclusion S.pyrogenes isolates in Guangdong province were susceptible to penicillin but resistant to erythrocin.emm 12.0 accounted for the majority of the three types and there was a high frequency of super antigen genes.

To explore the possibility to type the Brucella strains isolated in Guangdong province with analytical method to detect the fatty acid components and to collect the basic data of fatty acid components of Brucella strains, 29 strains of Brucella were selected for analysis on the bacterial fatty acid components and the cluster analysis on the collected data was performed with Sherlock analysis soft-ware (MIDI). It was demonstrated that the main fatty acid components of Brucella strains isolated in Guangdong province were 19∶0 cycloω8c acid, 16∶0 acid and 18∶0 acid. The content of 19∶0cycloω8c acid was highest in B.abortus, followed by B.melitensis and lowest in B.suis.-In addition, the content differences of 19∶0cycloω8c and 18∶0 acid between B. melitensis and Brucella suis were statistically significant; and that of 19∶0cycloω8c and 18∶0 acid between strains isolated in 1965 and those isolated in recent 3 years was statistically significant. It was also shown that the fatty acid components of Brucella strains were stable, but the contents of fatty acid components were different in different species.-It is evident that at certain euclidean distance, 3 species of Brucella can be differentiated in species level.

Objective To investigate the antimicrobial resistance pattern of non-typhoidal Salmonella isolated from diarrhea cases in Guangdong province,China.The multidrug-resistant strains were analyzed by pulsed field gel electrophoresis(PFGE) typing.Methods All the non-typhoidal Salmonella strains isolated between 2009 and 2011 were serotyped,then the antimicrobial resistance was detected by the disk diffusion method and molecular typed by PFGE.Results 91.76％ (256/279) S.typhimurium isolates were multiple resistant to 3 and more antimicrobials.Forty S.typhimurium isolates were multiple resistant to 9 and more antimicrobials and 3 out of which were multiple resistant to all the 12 antimicrobials in vitro.96.91％ (94/97) Salmonella I4,5,12:i:-isolates were multiple resistant to 3 and more antimicrobials.Nine Salmonella I4,5,12:i:- isolates were multiple resistant to 9 and more antimicrobials and I out of which was multiple resistant to all the 12 antimicrobials1 in vitro.47％ (47/100) S.enteritidis isolates were multiple resistant to 3 and more antimicrobials.Only 1 S.enteritidis isolates was multiple resistant to 9 and more antimicrobials.4.27％ (27/632) non-typhoidal Salmonella isolates was resistant to ciprofloxacin,including 17 S.typhimurium and 6 Salmonella 14,5,12:i:- isolates.Also,there were 3 1.96％ ( 202/632 ) non-typhoidal Salmonella isolates was intermediary to ciprofloxacin.The PFGE patterns of the predominant strains which were highly resistant and multidrug-resistant had different genotypes and demonstrated significant genetic diversity.Conclusion The situation about the multiple antimicrobial resistances of non-typhoidal Salmonella in Guangdong province has showed the prevalent problem.The PFGE types of the multiple drug-resistant strains prompted these strains were come from different clones.This requires that we continue to strengthen the resistance monitoring and control of the rational use of antibiotics.

To compare and evaluate the discriminatory ability and potential value of pulsed field gel electrophoresis (PF-GE) and multiple locus VNTRs analysis (MLVA) on the genotyping of Brucella ,a total of 60 strains of Brucella and three standards (16M ,544A ,1330S) were genotyped simultaneously by PFGE and MLVA .The result indicated that the similarity coefficient among the 63 isolates was from 72 .1-100 .0% by PFGE ,and could distinguish three species of B .melitensis ,B .su-is and B .abortus at the similarity level of 94 .4% .There were 14 clusters and 29 PFGE types identified by PFGE with discrim-inatory index (DI) of 0 .957 5 at the similarity level of 100% ;the similarity coefficient among the 63 isolates was from 16 .9-100 .0% by MLVA ,and could distinguish three species of Brucella at the similarity level of 52 .3% .There were 8 clusters and 47 MLVA types identified by MLVA with discriminatory index (DI) of 0 .985 2 at the similarity level of 100% .It's suggested that PFGE and MLVA could be used to distinguish three species of Brucella in the similarity coefficient of certain ,but could not effectively distinguish the type in the same species .Both of these two methods could be used for Brucella molecular typing , but MLVA is better than PFGE for its relatively higher discriminating ability .

Objective To provide scientific evidence to identify and confirm severe acute respiratory syndrome (SARS) by laboratory detection.Methods Multiple clinical specimens were collected serially and systematically from the 4 suspected SARS patients, which occurred between Dec.2003 to Jan.2004 in Guangdong Province. The samples were tested by serologic and molecular methods.Results IgM or IgG antibodies against SARS-CoV were detectable after 6—8 days of the onset in four patients. The four-fold or greater rising in antibodies was clearly detected in three of the four patients, while the fourth patient’s seroconversion was from negative to positive. The results analysed by enzyme-linked immunosorbent assay( ELISA), immunoflourescence assay (IFA), and neutralization test were highly correlated. SARS-CoV RNA was just detected in 3 throat swab specimens from case 1 by real-time PCR. M, N and S genes were amplified by reverse transcriptase polymerase chain reaction (RT-PCR) from the positive samples. Sequencing results showed that they were SARS-CoV gene segments, and most closely matched SARS-CoV gene sequences were isolated from civet cats in Guangdong Province. Nevertheless, SARS-CoV was not isolated from any samples of the 4 patients.Conclusion Based on these results, the 4 reported cases were laboratorily confirmed as SARS cases.

OBJECTIVETo analyze the etiologic characteristics of O1/O139 Vibrio cholerae in Guangdong province in 2009-2013.

METHODSIsolates from cholera cases and from the environment surveillance points were investigated by serological typing, antibiotic susceptibility testings, toxic genes detection and molecular typing to analyze the similarities and differences of the identified species.

RESULTSTotally, 190 isolations of O1/O139 V. cholerae were obtained from cholera cases (16 strains) and environmental samples (174 strains) in Guangdong province in 2009-2013. The sero-types would include Inaba (3 isolates), Ogawa (7 isolates) and O139 (6 isolates) in all the isolates from the cholera cases. Ten strains from the ctxA positive cases were detected by PCR. Two Ogawa strains carried incomplete CTXΦ phage. Results from the antibiotic susceptibility test indicated that 5 strains were absolutely sensitive to 11 antibiotic discs in vitro, while another 3 strains were simultaneously resistant to 4 antibiotic discs. Except for 2 stains, all the O139 strains from the environment were ctxA negative, detected by PCR. Incomplete CTXΦ phage was found in the Inaba (53 isolates), Ogawa (22 isolates) and O139 (2 isolates), respectively. Results from the antibiotic susceptibility test exhibited that 25 strains were resistant simultaneously to 4 and/or more antibiotic discs, especially the Inaba strains from the seafoods(13 isolates). 2 Inaba strains from seafood were simultaneously resistant to 7 antibiotic discs. Results from PFGE molecular typing indicated that the PFGE types digested by Not I expressed significant diversity. Inaba and O139 strains from cases were gathered in the same clusters, while the Ogawa strains from cases scattered in different clusters but no significant correlation among these strains were found. Our results suggested that a distant genetic relationship might exist between these two different sources strains.

CONCLUSIONComplex and diverse as the virulence genes and genetic characteristics and with the grim situation of multi-drug resistant strains, all seemed important to strengthen the surveillance programs on the variation of strain types and antibiotics resistance of O1/O139 V. cholerae in Guangdong province.

Bacterial Typing Techniques ; China ; epidemiology ; Cholera ; epidemiology ; microbiology ; Drug Resistance, Multiple, Bacterial ; Genes, Bacterial ; Humans ; Microbial Sensitivity Tests ; Vibrio cholerae ; classification ; drug effects ; isolation & purification ; Virulence