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Objective: To understand the serotype distribution, drug resistance and molecular characterization of invasive non-typhoid Salmonella (iNTS) in Guangdong Province from 2018 to 2022 and provide scientific evidence for the prevention and treatment of blood flow infection caused by Salmonella . Methods: Serological identification, antimicrobial susceptibility testing, multilocus sequence typing (MLST), and whole genome sequencing were performed on Salmonella isolated from blood and stool samples in Guangdong from 2018 to 2022. Simultaneously, annotated the sequencing results for drug resistance genes and virulence factors by a microbial gene annotation system. Results: The 136 iNTS strains were divided into 25 serotypes, and Salmonella enteritidis accounted for 38.24% (52/136). The OR of other iNTS serotypes were calculated with Salmonella typhimurium as the control. The OR values of Oreninburg , Rysson, and Pomona serotypes were the highest, which were 423.50, 352.92, and 211.75, respectively. The drug resistance rate of iNTS was 0.74%-66.91%, which was lower than that of non-iNTS (3.90%-77.21%). The main iNTS of drug resistance were ampicillin and tetracycline, with resistance rates of 66.91% (91/136) and 50.00% (68/136), respectively, while the resistance rates to ciprofloxacin (5.88%,8/136), ceftazidime (5.88%,8/136), gentamicin (5.13%,7/136) and cefoxitin (0.74%, 1/136) were relatively low. iNTS carried a variety of drug-resistance genes and virulence factors, but no standard virulence factor distribution has been found. MLST cluster analysis showed that iNTS was divided into 26 sequence types, and ST11 accounted for 38.24% (52/136). Conclusions: The iNTS strains in Guangdong were dominated by Salmonella enteritidis , of which three serotypes, Oreninburg, Rison , and Pomona , may be associated with a higher risk of invasive infection during 2018 to 2022 . iNTS was sensitive to clinical first-line therapeutic drugs (cephalosporins and fluoroquinolones), with highly diverse sequences and clear phylogenetic branches. ST11 was the local dominant clone group.

Objective: To analysis the curative effect of emergency cholecystectomy (EC) and percutaneous transhepatic gallbladder drainage (PTGBD) followed by delayed cholecystectomy (DC) on the patients with moderate acute cholecystitis. Methods: The perioperative dataof patients in EC group ( n =47) and in PTGBD-DC group ( n =49) were compared retrospectively. Results: Compared to PTGBD+ DC group, EC patients had a significantly more postoperative abdominal drainage time [(9.0±12.9) vs (3.4±2.1) days, P =0.041], more postoperative hospital stay after cholecystectomy [(8.2±3.2) vs (5.1±1.8) days, P =0.004], more intraoperative bleeding [(101±125) vs (33±37) ml, P =0.003], more patients of LC conversion to open cholecystectomy (OC) (19.1% vs 4.1%, P =0.021) and more patients of OC(14.9% vs 0, P =0.005). Also, there were higher incidence of respiratory failure(14.8% vs 2.0%, P =0.029), and admission for ICU(21.3% vs 2.0 %, P =0.003). Also, patients of total OC in non-biliary surgeons group were more than that of biliary surgeons group statistically(63.2% vs 14.3 %, P =0.001). Conclusion: PTGBD followed by DC in the treatment of moderate acute cholecystitis was better than EC, especially in patients with complicated comorbidities and in non-biliary surgeons.

Objective: To understand the circulation, drug resistance and molecular characteristics of Salmonella1 , 4, [5], 12: i:- in human in Guangdong province. Methods: Salmonella1 , 4, [5], 12: i:- isolated from diarrhea patients in Guangdong during 2007-2016 were detected for drug resistance, genes and PFGE characteristics. Results: A total of 2 960 strains Salmonella1 , 4, [5], 12: i: - were isolated from human diarrhea cases during this period. The positive rates of the isolation increased year by year. The male to female ratio of the infection cases was 1.58∶1, and the infection mainly occurred in infants and young children. Except imipenem, Salmonella1 , 4, [5], 12: i: - was resistant to other 17 antibiotics to some extent. The drug resistant rates to ceftazidime, cefotaxime and ciprofloxacin increased from 2011 to 2016. Multi-drug resistance was serious, for example, the multi-drug resistant strains with ASSuT accounted for 70.62% (435/616) and the multi-drug resistant strains with ACSuGSTTm accounted for 27.11% (167/616). The lack of fljA , fljB and hin genes, as well as the retaining of iroB , STM2740, STM2757 genes, resulted in the unable expression of FljBenx gene with 8 different defection profiles. There were 934 different PFGE patterns observed in 2 347 strains, which displayed a relatively large fingerprint polymorphism. The major PFGE pattern was JPXX01. GD0226, which was found in 97 strains, accounting for 4.13% (97/2 347). The PFGE patterns in 168 Salmonella1 , 4, [5], 12: i: - strains were consistent with that of Salmonella typhimurium. Conclusions: Salmonella1 ,4,[5], 12: i: - strains has become the major serotype of Salmonella that cause diarrhea in human in Guangdong. The multi-drug resistance of Salmonella1 ,4, [5], 12: i: - was serious, and since the defection of fljA , fljB and hin genes, the expression of FljBenx protein failed. The PFGE results were diverse, which displayed polymorphism in inheritance.

Objective: To investigated the etiologic characteristics of Shigella (S.) sonnei strains causing outbreaks and sporadic cases in some areas of Guangdong province and Guangxi Zhuang Autonomous Region during 2014-2016. Methods: Fourteen S. sonnei strains isolated from outbreaks and 6 S. sonnei strains from sporadic cases from Guangdong and Liuzhou of Guangxi Zhuang Autonomous Region were tested for antimicrobial resistance and analyzed by pulsed-field gel electrophoresis (PFGE). Six typical strains were selected for whole genome sequencing typing and compared with 51 strains isolated both at home and abroad from NCBI genome database. Results: The antibiotic resistance test indicated the isolates had high resistance rate to ampicillin, tetracycline, gentamicin, trimethoprim/sulfamethoxazole and nalidixic acid, while sensitive to azithromycin, chloromycetin and imipenem. PFGE showed high similarity (93.2%) among the strains isolated from different areas. The whole genome sequencing analysis also revealed that all the typical strains were clustered into a same evolution branch, close to some strains from Korea. Conclusions: The S. sonnei strains isolated from some areas of Guangdong and Guangxi Zhuang Autonomous Region showed high resistance to commonly used antibiotics, but they were sensitive to azithromycin, chloramphenicol and imipenem. The isolates in this study also showed similar PFGE patterns and close phylogenic evolution.

Objective: To analyze transmission factors of norovirus outbreaks in Guangdong province during 2008-2015 and provide evidence for the prevention and control of norovirus infection. Methods: Epidemiological analysis was performed on the data of norovirus outbreaks reported in Guangdong from January 1, 2008 to December 31, 2015, which were obtained from the Public Health Emergency Management Information System of Guangdong province. The samples collected from the norovirus outbreaks were detected for norovirus by RT-PCR and the gene sequencing of the positive PCR products were performed. Results: A total of 96 norovirus outbreaks were reported in Guangdong during 2008-2015. Sixteen outbreaks were reported during 2008-2012 and 80 outbreaks were reported during 2013-2015 (83.3 % ). Eighty-two outbreaks (85.4 % ) occurred in schools. The infection routes included foodborne transmission in 39 outbreaks (40.6 % ), person to person transmission in 23 outbreaks (24.0 % ) and waterborne transmission in 8 outbreaks (7.3 % ). The gene sequencing results showed that variant GⅡ.4/Sydney2012 was the predominant pathogen for 6 of the 20 outbreaks (30.0 % ) during 2012-2013. Variant GⅡ.17 was the predominant pathogens for 33 of the 53 outbreaks (62.3 % ) during 2014-2015. Conclusion: The norovirus outbreaks in Guangdong during 2008-2015 were caused by foodborne and person to person transmissions of two emerging variant: GⅡ.4/Sydney2012 and GⅡ.17.

Objective: To study the infection status, serotypes, drug resistance and molecular characteristics of Salmonella, Shigella, Vibrio parahemolyticus , enterotoxigenic Escherichia ( E. ) coli (ETEC), pathogenic E. coli (EPEC), Shiga Toxin producing E. coli (STEC) and Enteroinvasive E. coli (EIEC) collected from diarrhea patients in Guangdong. Methods: The strains of Salmonella, Shigella, V. parahemolyticus and 4 kinds of E. coli isolated from foodborne diseases surveillance during 2013-2014 were collected to conduct serotyping, drug resistance test and pulsed-field gel electrophoresis (PFGE). Results: A total of 3 372 stains of pathogens were isolated from 57 834 stool samples during 2013-2014, the overall positive rate was 5.83 % and the positive rate of Salmonella was highest, followed by that of V. parahemolyticus , 4 kinds of E. coli and Shigella . And 3 213 strains of Salmonella were divided into 143 serotypes. The most prevalent serotypes were Salmonella typhimurium , 4, 5, 12: i:-, Enteritidis , Stanley and Derby . Salmonella was sensitive to cephalosporin and fluoroquinolones, and showed significant differences in drug resistance rate among different serotypes. In top 10 common serotypes, S. enteritidis and S. derby were most resistant to cephalosporin and ciprofloxacin respectively. PFGE was performed for 2 289 strains of Salmonella , showing distribution diversity and significant fingerprint polymorphisms. The 85 strains of V. parahemolyticus were divided into 10 serotypes, O3∶K6 (61.18 % ) was the most common serotype, followed by O4∶K8. The results showed that the carrying rate of virulence genes tdh (81.18 % ) was high, while the carrying rate of trh was low (7.06 % ), and there were 10 strains carrying no the two kinds of virulence genes. The sensitive rate of V. parahemolyticus to imipenem, nalidixic acid, SMZ-TMP, chloramphenicol and tetracycline were more than 95 % . Thirteen strains of Shigella were detected, including 9 strains of Shigella sonnei , 3 strains of Shigella flexneri and 1 strains of Shigella bogdii . The strains all showed sensitivity to ceftazidime, ciprofloxacin and chloramphenicol (76.92 % ). There were 86 strains of E. coli detected, including 29 strains of ETEC (33.72 % ), 27 strains of EPEC (31.39 % ), 27 strains of STEC (31.39 % ) and 3 strains of EIEC (3.48 % ). Conclusions: In the active etiological surveillance for foodborne diseases in Guangdong during 2013-2014, the detection rate of Salmonella was highest (5.57 % ), followed by that of V. parahemolyticus , 4 kinds of E. coli and Shigella . Salmonella , V. parahemolyticus and Shigella were sensitive to cephalosporin and fluoroquinolones. Clustered cases of Salmonella infection were found in the surveillance, but no outbreaks occurred.

Objective: To understand the effect of serotyping on Salmonella isolates, by use of Microsphere-based Liquid Array method, among diarrhea patients, in Guangdong., Methods: Salmonella isolated from humans in Guangdong province were serotyped on the Microsphere-based Liquid Array platform with SSA kit., Results: A total of 4 942 Salmonella strains with 189 serotypes, were identified in Guangdong province in 2010-2014. The top 100 serotypes accounted for 98.08% (4 847/4 942) of all the strains. 98% of the top 100 species serotypes could completely be serotyped with SSA kit. In order to detect O antigen among 198 isolates with SSA kit, 181 strains were carrying the O antigen, with the coincidence rate as 100%. However, under the SSA, 98.32% (528/537) of the H antigen could be detected and were consistent with the traditional serum agglutination test. The coincidence rate of fljB gene was 93.09% (175/188), with false negative rate and false positive rate of fljB gene as 7.35% (9/134) and 7.41% (4/54) respectively. The coincidence rate of sdf gene and Vi gene were 100%. 11 out of the 12 Salmonella strains could not be serotyped under the traditional methods but were successfully serotyped by the molecular serotyping method., Conclusions: Using the SSA kit, more than 96% of the anthropogenic Salmonella strains could be serotyped in Guangdong province. Comparing with the traditional methods, the coincidence rate of serotyping appeared over 98% . Under the Microsphere-based Liquid Array techniques, the molecular serotyping method appeared faster and more accurate on Salmonella serotyping than those traditional methods.

Objective: To analyze the epidemiological and etiological characteristics of diarrheal disease among children under 5 years of age in Guangdong province, in 2012., Methods: 64 hospitals in 21 cities were chosen as the diarrheal syndromic surveillance sites, of which 14 hospitals were selected to carry out etiological surveillance among children under 5 years of age, including isolation and culture of both Vibrio cholera and Shigella as well as nucleic acid detection of rotavirus and norovirus by PCR. Descriptive method was used to analyze data from syndromic and etiological surveillance programs on diarrheal, from 1932 parents of the children., Results: In 2012, the outpatient attendance rate on diarrheal among children under 5 years was 0.8%. The proportion of diarrheal in children under 5-year-olds was 63.5%, among the total number of diarrheal outpatients at the outpatient clinics under surveillance program. The morbidity of infectious diarrhea was 1454.5/10 million in children under 5 years of age. A total number of 1932 specimens were collected from children under 5 years of age, in the outpatient department. Among these specimens,Vibrio cholera appeared all negative but one was Shigella positive and proved to be Sh. sonnei. The positive rates of rotavirus and norovirus were 14.1% (273/1932)and 16.9% (326/1932). Both rotavirus and norovirus were found in 24 specimens, with a positive rate as 1.2% . 112 specimens were successfully gene sequenced for rotavirus, of which 33.9% as G1[P8] genotype, 25.9% as G9[P8], 12.5% as G2[P4] and 9.8% as G3[P8] respectively. 90 specimens were successfully gene-sequenced for norovirus, of which 76.7% as G II.4 genotype. Genetic subtypes of G II. 4/2006b, accounted for 50.0% and could be detected around the year except for June and December. New G II. 4/Sydney Strain_2012 was first detected in August and became the predominant in December. In addition, 5 specimens belonged to G I genotype with other 16 subtypes of G II., Conclusion: Results from our study proved that children under 5 years of age belonged to high-risk group for diarrheal disease in Guangdong province. Rotavirus and norovirus were both diverse in terms of genome.

Objective: In order to better understand the nature of Salmonella infection in diarrheal patients in Guangdong province, the study analyzed the serum types, antibiotic resistance and molecular determinants of the isolated Salmonella strains., Methods: In year 2010, 8405 diarrhea patients from 16 surveillant hospital in Guangzhou, Zhongshan, Dongguan, Zhuhai, Maoming, Yangjiang and Jiangmen cities in Guangdong province, were recruited in the study. A total of 8405 fecal specimen were collected and subjected to Salmonella isolation and culture. The isolated Salmonella strains were further analyzed via serotyping, antimicrobial susceptibility testing, and PFGE. The χ(2) test was applied to compare the differences between the isolated Salmonella strains in different seasons and districts. BioNumerics software was used to analyze the PFGE results in order to determine the correlation between different Salmonella strains., Results: The positive rate of the surveillant Salmonella in Guangdong province was 3.58% (301/8405) in 2010; with the gender ratio at 1.34:1 (166/124). Salmonella infection was found in all age groups, and most in infants, accounting for 57.48% (173/301). The isolated rates of Salmonella were separately 3.48% (61/1751), 4.97% (134/2695), 3.08% (73/2370) and 2.08% (33/1589) in the four seasons; and the difference was statistically significant (χ(2) = 27.29, P < 0.01). The isolated rates of Salmonella in different regions were as follows: Zhuhai 15.43% (25/162), Maoming 7.53% (18/239), Dongguan 6.51% (39/599), Yangjiang 3.64% (14/385), Zhongshan 3.03% (70/2309), Guangzhou 2.90% (126/4349) and Jiangmen 2.49% (9/362). The difference between regions was statistically significant (χ(2) = 100.75, P < 0.01). Except one strain of the isolated Salmonella cannot be serotyped, the other 300 strains were divided into 42 serotypes, of which Salmonella typhimurium and Salmonella enteritidis were dominant, account for 45.18% (136/301) and 10.96% (33/301) respectively. Although over 85% of Salmonella were sensitive to cephalosporin, ACSSuT resistance patterns (defined as resistance to at least ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and tetracycline) reached 34.88% (105/301), the highest resistant rate was found in serotype Salmonella typhimurium, as high as 65.44% (89/136). 136 strains of Salmonella typhimurium were divided into 51 PFGE types, showed great genetic diversity. 33 strains of Salmonella enteritidis were divided into 18 PFGE types. The strains with same PFGE pattern may have different drug-resistant patterns, and vice versa., Conclusion: Salmonella typhimurium and Salmonella enteritidis were the dominant serotypes causing infectious diarrhea in Guangdong province. Cephalosporin was the primary choice in clinical medicine. However, Salmonella typhimurium was resistant to drug most seriously in Guangdong province. There was no significant correlation between Salmonella resistance patterns and PFGE type.

Objective: To understand the pathogen-carrying status of hand-foot-mouth disease (HFMD) among healthy people in Guangdong province., Methods: Stool specimens were collected randomly on 7 age groups from 7 cities in Guangdong province. Real-time RT-PCR was used to detect enterovirus (EV), enterovirus 71 (EV71) and coxsackie virus A16 (CA16)., Results: Altogether, 1285 stool specimens were collected. The positive rates of EV71, CA16 and other enterovirus were 0.39% (5/1285), 0.23% (3/1285) and 7.00% (90/1285), respectively. The highest EV71 positive rate (1.79%) was among the 4-6-year-old group, followed by the age group 0 - 3 with positive rate as 0.67%. EV71 was not found among the rest age groups. The highest CA16 positive rate (1.35%) was among the 4 - 6 year-olds group, but the CA16 was not found among the rest age groups. EV71 was only found among native population, with the positive-rate as 0.47%. CA16-positive rate was 0.19% among the native population and 0.85% among floating population, with no significant difference found (P > 0.05). The EV71 positive rate was 0.36% among rural residents and 0.54% among urban residents, but with no significant difference (P > 0.05). All CA16 was found among the urban residents., Conclusion: Recessive infection of EV71 and CA16 were only found among 0-6 year-old group but not found among other groups, which suggested that the approaches on prevention and control should be targeted to all children especially on pre-school children.

Objective: To understand the distribution, molecular characteristics and virulence genes of the O1 and O139 Vibrio cholerae isolates from the Pearl River Estuary water., Methods: Vibrio cholerae isolates collected from the Pearl River estuary waters from January 2009 to December 2010, were tested by PCR for eight virulence-related genes, including cholera toxin (ctxA), zonula occludens toxin (zot), accessory cholera enterotoxin (ace), hemolysin (hlyA), toxin-coregulated pilus (tcpA), outer membrane protein (ompU), and the regulatory protein genes (tcpI, toxR). Genetic relation was assessed by pulsed-field gel electrophoresis (PFGE) and the patterns were clustered by BioNumerics., Results: From 1152 aquatic samples, 69 isolates were identified, including 41 Inaba, 18 Ogawa and 10 O139. All the isolates showed ctxA negative, while the hlyA and toxR genes were positive in all the isolates. 34.15% (14/41) of the Inaba strains were hlyA(+) toxR(+) ompU(+) ace(+) zot(+) tcpI(+), while 66.67% (12/18) belonged to Ogawa strains and 70% (7/10) of the O139 strains were hlyA(+) toxR(+). Through PFGE analysis, the O1 isolates formed three clusters in this study. The patterns of O1 isolates differed widely, with the similarity as 72.8% - 100.0%, while the patterns of O139 isolates having the similarity of 69.9% - 95.5%., Conclusion: The non-toxigenic O1 and O139 V. cholerae had a wide distribution in the environment of Pearl River estuary water during the non-epidemic period of cholera. All the aquatic isolates presented diversities on the related virulent genes.

Objective: To study the serotypes, virulence features and molecular characteristics of Vibrio parahaemolyticus isolated in food poisoning cases and surveillance program on diarrhea patients in Guangdong, 2009., Methods: 95 Vibrio parahaemolyticus strains from food poisoning cases and 15 strains from surveillance program on diarrhea patients were serotyped and detected for tdh (thermostable direct hemolysin, tdh) and trh (tdh-related hemolysin gene, trh) by PCR. 81 sero-variant Vibrio parahaemolyticus strains were selected through PFGE subtyping., Results: There were 15 Vibrio parahaemolyticus strains isolated from surveillance program on diarrhea patients and 95 strains were isolated from 11 Vibrio parahaemolyticus-caused food poisoning cases in 2009. Among these strains, O3:K6 (46.67% and 44.21%) and O4:K8 (33.33% and 28.42%) were the dominant serotypes, but not the 7 food-borne strains. There were 93 (84.54%) tdh(+)trh(-), 13 (11.81%) tdh(-)trh(-), and 3 (3.65%) tdh(+)trh(+) strains. The similarity value was between 57.7% to 100.0% of the 81 strains after PFGE sub-typing method and 36 PFGE subtypes were identified. PFGE001 and PFGE029 appeared to be the dominant subtypes., Conclusion: O3:K6 and O4:K8 were the most dominant serotypes in Vibrio parahaemolyticus-caused diarrhea and food poisoning cases in Guangdong and tdh were detected in most of the strains. Dominant PFGE subtypes were causing both sporadic and outbreak cases in different areas in Guangdong province.

Objective: To understand the phenotypic characteristics of foodborne Vibrio parahaemolyticus in Guangdong province through carrying out a comprehensive comparison including pulse field gel electrophoresis, ribotyping and serotyping., Methods: 74 different Vibrio parahaemolyticus strains isolated from seafood and cases due to food poisoning in Guangdong province were under serotyping and susceptibility testing, in addition to the testing of direct heat hemolysin (tdh) and the heat hemolysin-related hemolysin hormone (trh) via PCR. Ribosomal genotyping (ribotyping) with EcoR I restriction enzyme was utilized on 74 different Vibrio parahaemolyticus isolates, whereas pulsed-field gel electrophoresis (PFGE) with the Not I restriction enzyme was used on 74 different Vibrio parahaemolyticus isolates. BioNumerics software was used to compare the isolates from different sources, times and places in order to elicit the correlation between different strains., Results: Although Vibrio parahaemolyticus was 100.00% sensitive to chloramphenicol, it still presented different levels of resistance against 13 other antibiotics. Among the 74 different strains of Vibrio parahaemolyticus under testing, 24.32% showed positive for the tdh virulence gene, whereas 4.05% positive for trh. 74 different Vibrio parahaemolyticus strains were found to belong to 26 serotypes, where the O5:K17 and O2:K28 serotypes were dominant in those isolates that causing seafood-poisoning. The O3:K6 serotype was found to be the dominant of those isolates that causing food-poisoning. Based on ribosomal genotyping, the 74 Vibrio parahaemolyticus isolates were divided into 62 different ribotypes, whereas the 74 strains of Vibrio parahaemolyticus were divided into 67 different PFGE types, thus exhibiting considerable genetic diversities of the strains., Conclusion: Majority of the isolates causing food-poisoning carried tdh virulence gene. PFGE was shown to have the highest resolution, followed by ribotyping with serotyping being the lowest, where the combination of the three could improve the resolution.

Objective: To clarify the diagnosis of one suspected case of diphtheria in Guangdong province by epidemiological analysis and etiologic detection., Methods: On July 6th 2010, the corynebacterium diphtheria was detected from the nasal secretions of one nasopharyngeal carcinoma patient in a college-town hospital in Guangzhou City, Guangdong Province. The patient and the close contacts were asked to participate in the epidemiological survey; and their nasopharyngeal swabs (3 samples) and the nasal secretions of the patient (1 sample) were collected. The bacteria of the samples were isolated and cultured by blood plate and agar loefflera. The smears of positive strains were dyed and identified by BioMerieux API Coryne biochemical card. Gene tox of β-Corynebacteriophage, Corynebacterium diphtheriae was tested by PCR method, the aliphatic acid was analyzed by gas chromatography method and the Corynebacterium diphtheriae (CMCC 38009) was selected as positive control., Results: The patient had not gone out, neither had been visited. The patient denied history of vaccines or the immunizations. From the survey on patient's family members and close contacts, no similar symptoms had been found. One strain of Corynebacterium diphtheriae was isolated from the patient's nasal secretions, Gram positive and shape diversified. After cultured by agar loefflera and Gram-dyed and Neisser-dyed, one end or both two ends of the strain showed typical metachromatic granule. API Coryne was identified to Corynebacterium diphtheriae mitis/belfanti (99.4%). The result of gas chromatography method also indicated Corynebacterium diphtheriae. No Corynebacterium diphtheriae was isolated from the nasopharyngeal swabs, neither of the patient nor of the close contacts. The gene tox of β-Corynebacteriophage, Corynebacterium diphtheriae was negative according to the PCR test., Conclusion: The isolated Corynebacterium diphtheriae did not produce toxin as there was no biological structure gene of toxin. The patient was a health carrier of nontoxic Corynebacterium diphtheriae.

Objective: To investigate the pathogens of acute respiratory infection (ARI) in Guangzhou from 2006 to 2009., Methods: A total of 1554 cases of ARI patients in Second Affiliated Hospital of Guangzhou Medical College from September 2006 to September 2009, were recruited in the survey. The sample of throat and pharyngeal swab were collected from each patient.11 types of virus including influenza A (FluA), influenza B (FluB), adenovirus (ADV), human rhinovirus (HRV), respiratory syncytial virus (RSV), parainfluenza virus type 1, type 2, type 3 (HPIV1, HPIV2, HPIV3), human metapneumovirus (MPV) and human coronavirus (HCoV) type 229E, type OC43 were detected by Fluorescence Quota PCR method. The epidemic feature and clinical characteristic of each virus were then analyzed., Results: Virus were found in 1024 samples in total, accounting for 65.9% (1024/1554). RSV was the most common virus, which was found in 261 samples (16.8%); and followed by HRV as 13.9% (216/1554), FluA as 11.6% (181/1554), MPV as 6.5% (101/1554), FluB as 6.4% (99/1554), HPIV as 4.9% (76/1554), ADV as 3.5% (55/1554) and HCoV as 2.3% (35/1554). HPIV and HCoV shared a similar infection ratio among different age groups. The infection ratio of FluA and FluB was highest among 15-24 years old group, accounting for 16.5% (29/176) and 7.4% (13/176) respectively. MPV, RSV and HRV were the main pathogens caused infection among children under 4 years old, accounting for 9.7% (49/503), 21.7% (109/503) and 18.9% (95/503). The infection ratio of ADV was 6.0% (19/318), which was the most common pathogen among 5-14 years old patients. The incidence rate of HPIV and HRV showed no obvious seasonal features; while the prevalence of FluA, FluB, RSV, ADV, MPV and HCoV changed significantly in different seasons.22.2% (227/1024) ARI patients co-infected other respiratory virus.90.1% (163/181) FluA patients, 88.9% (88/99) FluB patients and 92.7% (51/55) ADV patients had high fever symptoms., Conclusion: RSV was the main pathogen of ARI, and the new-found virus MPV was also another crucial pathogen. Some pathogens' incidence rate were related to the season and patient's age. Co-infections of other respiratory virus were also detected in parts of ARI patients.

Objective: To understand the genetic polymorphism of Salmonella and Staphylococcus aureus in Guangdong province, as well as to explore methods for identifying and tracing the source of these two foodborne pathogens., Methods: Using the automated ribotyping system, two foodborne pathogens were tested with either EcoR I or Pvu II restriction enzymes. BioNumerics software was then applied for image analysis, database establishment and other corresponding analysis., Results: Digestion of 32 Salmonella isolates with Pvu II yielded 19 different ribotypes, and digestion of 14 Salmonella isolates with EcoR I yielded 2 different ribotypes. Staphylococcus aureus isolates showed greater genetic diversity, whereas EcoR I digestion of 49 different isolates yielded 31 different ribotypes., Conclusion: Unique Salmonella and Staphylococcus aureus isolates could be identified through ribotyping. Although Salmonella serotyping and ribotyping were not strongly correlated, the combination of both restriction enzymes could be used to more effectively identify the genetic relationship among different strains as well as the source of food poisoning. Thus, not only could the genetic relationships amongst the different strains be inferred through ribotyping skills, the source of food poisoning and mode of transmission could also be determined under the use of this method.

Objective: To understand the infection of Salmonella (S.) in patients with diarrhea and outbreaks caused by Salmonella to identify the serotypes, resistance to antibiotics and PFGE types of the strains from the surveillance program in Guangdong province., Methods: S. strains from patients with diarrhea were detected, and all the positive strains collected in routine and outbreak surveillance programs, were tested by serum agglutination, antibiotic susceptibility and PFGE., Results: 71 S. strains were isolated from 1922 stool samples in 2008, with positive rate as 3.7%. 85 S. strains were isolated from 2110 stool samples in 2009, with positive rate as 4.0%. All the 156 strains were divided into 37 serotypes, with S. serotype typhimurium and enteritidis as the most common serotypes. 10 incidents of food poisoning were detected, of which 4 were caused by enteritidis and 3 by typhimurium. A suspected outbreak by enteritidis was discovered and under epidemiological investigation. The findings indicated that 2 of the 4 patients from this outbreak were infected with identical enteritidis isolates. 80% of the 229 isolates were found susceptible to cephalosporins and quinolone and 59.3% of them were multiresistant to the antibiotics., Conclusion: S. enteritidis and S. typhimurium were the most common serotypes that caused infectious diarrhoea and food poisoning in Guangdong province.

Objective: To evaluate the outcomes after laparoscopic gastrointestinal surgery for patients with obesity and type 2 diabetes mellitus(T2DM)., Methods: From June 2003 to June 2010, 219 patients underwent laparoscopic gastrointestinal surgery for obesity and T2DM, including laparoscopic adjustable gastric banding(LAGB, n=201), laparoscopic mini gastric bypass(LMGB, n=13), and laparoscopic sleeve gastrectomy(LSG, n=5). Clinical data were analyzed retrospectively., Results: The mean body mass index(BMI) of patients who received LAGB was 37.9 kg/m(2), and decreased to 32.4 kg/m(2) at 6 months and to 29.7 kg/m(2) at 12 months. In 43 patients who had concurrent T2DM, 11(25.6%) showed clinical partial remission(CPR) and 16(37.2%) clinical complete remission (CCR). Postoperative complications occurred in 26 patients(12.9%). The mean BMI of patients undergoing LMGB was 34.7 kg/m(2), and decreased to 31.6 kg/m(2) at 6 months and 26.9 kg/m(2) at 12 months after surgery. Ten patients had T2DM before operation, of whom 2(20.0%) had CPR and 7(70.0%) CCR postoperatively. Postoperative complications occurred in 2 patients(15.4%). The mean BMI of patients who underwent LSG was 43.8 kg/m(2), and was reduced to 38.1 kg/m(2) at 6 months and 34.3 kg/m(2) at 12 months after operation. Three patients were diagnosed with T2DM before operation. One patient (33.3%) had CPR and 1(33.3%) reached CCR after operation. There was 1(20.0%) patient who developed complication. No perioperative death occurred., Conclusion: Laparoscopic gastrointestinal surgery may result in satisfactory weight loss and clinical remission of T2DM with few complications.

Objective: To investigate the effects of Gastric bypass surgery on the apoptosis of islet β-cells in type 2 nonobese diabetic (NOD) rats and its mechanisms., Methods: Seventy-two 8-week-old GK rats were randomly divided into four groups:operation group (group O, n = 18), sham operation group (group S, n = 18), diet control group (group F, n = 18) and control group (group C, n = 18). The levels of fasting, postprandial blood glucose, insulin and glucagon-like peptide-1 (GLP-1) were measured and compared among the 4 groups before the operation and at 1, 2, 4 and 8 weeks following the operation. The blood samples were collected at 2, 4 and 8 weeks after the operation for the measurement of postprandial blood glucose, and then the rats in batches (6 rats in each group) were decapitated to retrieve the pancreas. The apoptosis of the islet β-cells was detected by using TUNEL assay, and the expression of apoptosis-related proteins Bcl-2, Bax was measured with immunohistochemistry., Results: As for group O, the fasting blood glucose level decreased from (16.2 ± 0.8) mmol/L before the operation to respectively (9.2 ± 0.6) mmol/L and (9.7 ± 0.7) mmol/L at 4 and 8 weeks after the operation; postprandial blood glucose decreased from (31.1 ± 1.1) mmol/L before the operation to respectively (13.1 ± 0.7) mmol/L and (12.3 ± 0.7) mmol/L at 4 and 8 weeks after the operation. Fasting insulin level increased from (28.0 ± 1.2) mU/L before the operation to respectively (62.8 ± 1.9) mU/L and (61.7 ± 1.4) mU/L at 4 and 8 weeks after the operation; and at 4 and 8 weeks after the operation postprandial insulin level was (77.4 ± 1.1) mU/L and (77.1 ± 1.0) mU/L. At 2 weeks from the operation, the fasting GLP-1 in group O increased from (10.7 ± 1.0) pmol/L to (13.5 ± 0.8) pmol/L, and respectively to (26.1 ± 0.9) pmol/L and (25.3 ± 1.2) pmol/L at 4 and 8 weeks after the operation. The differences in the above-mentioned items before and after the operation were all significant in group O (P < 0.05), and the differences in the items among group O and the other three groups (P < 0.05) were all significant as well. In group O, the apoptosis rate of pancreatic islet cell decreased to (5.9 ± 0.7)% at 4 weeks from the operation, and (6.3 ± 1.1)% at 8 weeks from the operation (P < 0.05). The expression of Bcl-2 protein in group O was 31.3 ± 1.5, 35.7 ± 1.0 and 35.8 ± 0.8 at 2, 4 and 8 weeks post operation, which was significantly higher in statistics than those of the same time point in the other three groups (P < 0.05). The expression of Bax protein in group O was 13.3 ± 0.9, 10.8 ± 0.9 and 10.9 ± 1.1 at 2, 4 and 8 weeks from the operation, which was significantly lower in statistics than those of the same time point in the other three groups (P < 0.05)., Conclusions: Gastric bypass surgery can significantly reduce the blood glucose level and promote the secretion of GLP-1, and therefore inhibit the apoptosis of the islet β cells in diabetic rats through the Bcl-2 pathway.

Objective: To prepare a DNA Microarray that can detect 8 common species of food borne bacterial pathogens in south China., Methods: All the 70mer oligo probes were designed on the characteristic genome loci of the 8 species of food borne bacterial pathogens. Eight subarrays corresponding to the 8 food borne bacterial pathogens were spotted onto the slide and integrated into a pan-array on the chip. A number of identified and known bacterial samples from the storage bank were selected for the validation test., Results: Based on the PPR ranking, for LM sub-array, the PPR of the 3 Listeria bacteria LM, Lin and Liv was 68.8%, 51.8% and 59.6%, respectively, while that of the non-Listeria bacterial samples was all below 43%. For VC sub-array, the PPR of VC sample was 54.1% and that of the non-VC bacterial samples was lower than 17.2%. For VP sub-array, the PPR was 66.7% for VP sample and below 24.2% for non-VP bacterial samples. For Sal sub-array, the PPR was 55.9% for Sal sample and below 50.5% for non-Sal bacterial samples. For Shi sub-array, the PPR of Shi sample and the non-Shi bacterial samples was 53.8% and below 36.6%, respectively. For SA sub-array, the PPR of SA sample and non-SA bacterial samples was 65.2% and below 22.7%, respectively. For CJ sub-array, the PPR of the 2 Campylobacter bacteria CJ and CC were 88.2% and 58.8%, respectively, and that of the non-Campylobacter bacterial samples was lower than 35.3%. For EC sub-array, the PPR of EC sample was 47.9%, and that of the non-EC bacterial samples was lower than 41.6%. Evaluation of the Biosafood-8 chip developed in this study by 18 biological samples from different origins demonstrated its good specificity and accuracy in the identification of the pathogens., Conclusion: The chip we developed can clearly differentiate the target food borne pathogenic bacteria and non-target bacteria and allows specific and accurate identification of the species of the tested bacteria isolates.

To study the molecular epidemiological characteristics of norovirus gastroenteritis outbreaks in Guangdong, we collected fecal and anal swabs specimens from 24 outbreaks of acute gastroenteritis from 2005 to 2008 to detect norovirus. Specimens were detected by RT-PCR and then sequenced. The descriptive data were also collected. According to our research, 19 of 24 outbreaks of gastroenteritis were positive for norovirus. The occurrence time was from October to next February mainly. The strains in 2005 belonged to G II-3 genotype and all outbreaks occurred in kindergarten and school. But from autumn of 2006, the outbreaks were all caused by G II-4/2006b variant and occurred in universities and community. The number of outbreaks in 2007 increased greatly and covered all over province. The nucleotide sequences of Guangdong strains in some sites showed high regional identity. Our results showed that with the shift of genotype from G II-3 to G II-4, occurrence of norovirus outbreaks increased greatly. The outbreaks of norovirus caused by G II-4/2006b variant spreaded widely and the involved population covered children and adult, indicating the strong invasiveness of this variant.

Objective: To report the newly developed reconstruction technique after laparoscopic total gastrectomy: intracorporeal circular stapling esophagojejunostomy using the transorally inserted anvil (OrVil; Covidien), and evaluate its feasibility, safety, and clinical outcomes., Methods: After LTG (3 patients with gastric carcinoma in the body) or LPG (2 patients with gastric carcinoma in the cardiac and fundus, respectively, and 1 with cardiac stromal tumor), the anvil was then inserted transorally into the esophagus by using the OrVil system. Double-stapling esophagojejunostomy or esophagogastrostomy with a circular stapler was performed intracorporeally., Results: The operations were uneventful. The operative time was (183.3+/-25.8) min, and blood loss was (128.3+/-90.2) ml. Postoperative fluorography revealed no anastomotic leakage or stenosis. Patients resumed an oral liquid diet on postoperative day (4.0+/-1.1), and were discharged on day (9.0+/-2.6). Patients were followed at 28 days and no complications were reported., Conclusions: LTG with Roux-en-Y reconstruction or LPG with esophagogastrostomy using the OrVil system appear to be safe and reliable with satisfactory short-term outcomes.

Objective: To study the status of norovirus in environment of the patient's residence and water samples after a norovirus gastroenteritis outbreak, to provide evidences for the development of strategies for prevention and control of the disease., Methods: After a norovirus gastroenteritis outbreak, anus swabs from the patient, swabs from the household environment and the water samples were collected to detect the norovirus by RT-PCR methods. Sequencing analysis was conducted on those positive specimens., Results: Three specimens of the anus swabs from 9 patients and 2 samples of the 46 house environment swabs were positive to the virus. The latter were from the surface of water-closets of two families that the illness were asymptomatic. Among 5 water samples, only one was positive, which was the rivulet water that the feces of the villagers evacuated directly., Results: showed that the sequences of the virus detected from the anus swabs of the patients, the swabs from the household environment and the samples of the rivulet water belonged to the same species., Conclusion: It is necessary to strengthen activities as supervision and disinfection to the feces of the patients, especially on monitoring the feces that might have contaminated the water during the norovirus gastroenteritis outbreak.

Objective: To evaluate the outcome of weight loss by laparoscopic adjustable gastric banding (LAGB) on obesity patients and the improvement of comorbidity., Methods: From June 2003 to June 2009, the data 172 obesity patients(119 women, 53 men, mean age 28.5 years, mean body mass index 38.5 kg/m(2)) were analyzed. Comorbidities included 28 cases with diabetes, 36 with hypertension, 85 with dyslipidemia, 56 with sleep apnea and 138 with fatty liver., Results: Mean body mass index(BMI) at 1,3,6,12, 24, 36 and 48 months was 37.2 kg/m(2),35.9 kg/m(2), 34.5 kg/m(2), 32.9 kg/m(2), 30.7 kg/m(2), 29.2 kg/m(2) and 28.1 kg/m(2), respectively. The percentage of excess weight loss(% EWL) at 1, 3, 6, 12, 24, 36, and 48 months was 10.1%, 16.2%, 25.1%, 37.4%, 51.3%, 59.0% and 62.1%, respectively. At 24, 36 and 48 months, respectively, 50.7%, 63.6% and 70.0% of patients had more than 50% excess weight loss. Complications included 6 cases of port infection, 3 of other port problem, 7 of gastric pouch dilatations, 4 of slippage and 1 of chronic intestinal obstruction. Bands of 5 patients were explanted. No death occurred. Blood glucose of 60.7% patients with diabetes was controlled well without any drug. The blood pressure of 22 hypertensive patients became normal. The blood fat of 49 hyperlipidemia cases returned to normal. The symptom of 29 patients with sleep apnea disappeared. All the patients with fatty liver were improved in different degree., Conclusion: Gastric banding provides good weight loss and significant reduction in comorbidities with few and minor complications.

Objective: To evaluate the short-term outcome of laparoscopic gastric bypass on obesity patients with type 2 diabetes mellitus., Methods: Seven obesity patients with type 2 diabetes mellitus received laparoscopic gastric bypass(n=1) or laparoscopic minigastric bypass(n=6), and their data of treatment outcomes were analyzed., Results: The operations were all successfully performed without any complications. The average operation time was 125 minutes(range: 100 to 170 minutes). The patients underwent 1-18 months follow-up after operation. Diabetic indicators returned to normal without any medication and body weight reduced by on average of 24.3 kg., Conclusion: Laparoscopic gastric bypass and minigastric bypass have good short-term outcome in the treatment of obesity patients with type 2 diabetes mellitus.

Objective: To find out the status of human metapneumovirus (hMPV) infection in children under 14 years old with acute respiratory tract infections (ARI) in Guangzhou, analyze the epidemiology and clinical characteristics among the hMPV-infected children, and provide some basis for research of hMPV., Methods: All 521 throat and pharyngeal swabs were collected among the children with acute respiratory tract infections in outpatient departments and those admitted to the wards from September 2006 to August 2008. Then total nucleic acid was extracted from respiratory specimens. The 213 nucleosides of nucleoprotein gene were detected by RT-PCR and 16 strong positive samples were picked to compare with the sequence of hMPV in GenBank after the sequence of the amplification products were determined. Then applied statistical analysis to the data of the collected patients., Results: All 521 samples were detected by RT-PCR, and confirmed that N gene was positive in 39 samples with a detection rate of 7.49%, and the peak time was in October and April. The 16 amplification products were compared by using the analysis of gene sequence. The nucleocapsid protein (N) gene similarity to BJ1897 of Beijing was up to 99%, and to AY550156 of Thailand was up to 97%, genotype B was the most common genotype., Conclusion: There existed hMPV infection in children acute respiratory system diseases in Guangzhou areas, in which the children under the age of 6 years were accounted for the main group, however there was no difference in gender. The main symptoms of the patients with hMPV infection were high fever and cough symptom of catarrh. Co-infections other than respiratory virus with hMPV were detected as 41.03% of positive samples.

Objective: To explore the benefit of neoadjuvant chemotherapy in advanced gastric cancer patients treated by laparoscopy., Methods: Fifteen patients with histologically proved gastric adenocarcinomas (stages II(, III(, IIII(M(0)) were treated with FOLFOX7 neoadjuvant chemotherapy followed by laparoscopy between June 2005 and March 2007( trial group). Thirty patients were assigned to the control group with only laparoscopic treatment in the same period. The clinicopathological data were compared between two groups., Results: All the patients in trial group accepted four cycles of preoperative chemotherapy and the toxicity was less than grade 3. Two of them achieved complete response, 10 achieved partial response and 3 kept stable disease. Ten patients of trial group underwent laparoscopic-assisted radical gastrectomy. The rates of R(0)-resection(80.0%) and pN(0) (60.0%) in trial group were significantly higher than those in control group(46.7% and 20.0%), while the rate of positive lymph node 11.0%(34/309) was significantly lower than that of control group 23.8%(142/596). The operation time and postoperative complication were similar in two groups., Conclusions: Advanced gastric cancer after neoadjuvant chemotherapy can be down-regulated in the stage, increase the rate of R(0)-resection, diminish the infiltration extent of tumor, decrease the metastasis of lymph node, and increase the possibility of laparoscopic radical gastrectomy.

Objective: To understand non-typhoid Salmonella in diarrhea patients from Guangdong province in order to timely discover the outbreaks caused by them as well as to grasp the serotypes, antibiotic resistance and pulse-field gel electrophoresis (PFGE) types of those strains isolated from this surveillance program., Methods: Salmonella strains from diarrhea patients were detected and all the positive strains were tested by serum agglutination, antibiotic susceptibility and PFGE., Results: 71 non-typhoid Salmonella strains were isolated from 1128 stool samples, with a positive rate of 6.29%. All the strains were divided into 29 serotypes, with Salmonella serotype enteritidis and typhimurium showing the most common serotypes. Most of the strains were sensitive to cephalosporins and quinolones. The antibiotic resistance rates of S. typhimurium were higher than S. enteritidis and S. stanley. Other than S. enteritidis, all the serotype strains did not have the same type of PFGE. 17 S. enteritidis strains digested by XbaI were divided to 8 PFGE types while the PFGE 4 type appeared the most common one. 12 S. enteritidis strains were typed again by SfiI and NotI, and there were still 3 groups of strains showing the same PFGE pattern., Conclusion: Most of the infection caused by non-typhoidal Salmonella was sporadic in Guangdong province in 2007. Cephalosporins and quinolones seemed the best in curing the infection of non-typhoidal Salmonella at the clinics.

Objective: Analyze the epidemiology character of the residual paralysis(RP) of acute flaccid paralysis (AFP) in Guangdong during 1994-2007., Methods: The viruses isolated from the excrement of RP cases were identified and typed in Guangdong from 1994 to 2007. Statistics analysis was performed to reveal the relationship among the immunization history,age,gender and the distribution of the etiology., Results: A total of 503 RP cases were reported. 150 of which were isolated with PV and 59 were isolated with NPEV. From 1994 to 2007, The PV isolating rate ranged from 18.92% to 47.06% and was higher in winter and spring, while the NPEV isolating rate ranged from 4.17% to 25.00%. and was higher in summer and autumn. The PV isolating rate decreased as the age increased,and its isolating rate (61.11%) was highest in "0" year group. The PV isolating rate of the population of < or =2 times OPV was far higher than 3 times. The PV and NPEV isolating rate of the RP cases was higher than without RP., Conclusion: The case with RP caused by wild poliovirus wasn't found from 1994 to 2007 in Guangdong, but the relationship of RP case was observed between < or =2 years group and < or =1 time OPV, and NPEVs probably are the potential etiological agent that cause children RP.

Objective: Intensive surveillance of human S.suis infection was carried out in July and August of 2005 in Guangdong Province, which coincided with the Sichuan outbreak. Five isolated cases of human infections were identified during this period, from which 5 S. suis serotype 2 isolates were recovered. MLST analysis showed that these 5 isolates shared identical sequences of 6 MLST housekeeping genes except for one point mutation found within the thrA gene fragment, a neutral mutation (TTA to TTG) in the third nucleotide (360 nt) of the codon for leucine. MLST analysis identified 2 sequence types in the Guangdong sporadic infection. Three Guangdong isolates L-SS002, L-SS003 and L-SS005 belonged to ST7, while the other two isolates L-SS004 and L-SS006 belonged to ST1, but they all belonged to ST1 clonal complex. This finding represents a striking feature that differs from the Sichuan outbreak caused by a single ST7 SS2 clone. The 3 isolates of ST7 were probably imported from Sichuan Province, while the origin of the other 2 isolates of ST1 still remain to be clarified.

Objective: To analyze the etiologic characteristics of Vibrio cholerae in Guangdong province in 2007. Genetic relationship was observed including among predominated biotype isolates from different areas within the province and among same biotypes isolates from cholera cases and regular surveillance., Methods: Isolates from cholera cases and through environmental surveillance were typed by sero- and phage- typings. Similarity of molecular fingerprinting was analyzed through comparing the pulsed field gel electrophoresis(PFGE) pattern of predominated biotype isolates, and those of the same biotype isolates from cholera cases a nd environment surveillance, respectively. In addition, genetic relationship was determined by clustering analysis, using bionumerics software., Results: In total, 31 isolates from cholera cases were collected and subtyped for 3 serogroups. V. cholerae O1 El Tor Inaba phage 1d was the predominant biotype which causing most of the cases in Guangdong province in 2007. Data from cluster analysis showed that the similarity among Inaba phage 1d strains from different areas were from 94.5% to 100%. However, 16 isolates were collected from environment surveillance programs and the predominated biotype could not be found. Additionally, the biotype distribution of cases isolates was not consistent with those isolates through surveillance. High phylogenetic diversity was observed for the same biotypes isolates from cases and surveillance samples., Conclusion: Our data showed that V. cholerae O1 El Tor Inaba phage 1d was the predominated biotype with multi-clone coexisting and circulating in Guangdong province in 2007. It also appeared to be the characteristics of cholera in the non-epidemic period, suggesting that it was necessary to enhance the alert surveillance programs for cholera epidemic based on the molecular typing techniques.

Objective: Through systematic monitoring of the number and strain types of O1 and O139 Vibrio cholerae in the Pearl River estuary waters to analyze it's relevance with the temperature of environment, and the relevance between strains in water and isolates during outbreaks and epidemics as well as to estimate the methods used for environmental water detection and the potential role in cholera surveillance program., Methods: Twenty-four stations along the Pearl River were selected and the water samples were collected monthly from March 2006 to February 2007. V. cholerae O1 and O139 strains were isolated from the samples. Real-time PCR established in our laboratory was used to detect V. cholerae O1 and O139. Air temperature and water temperature were collected during sampling. Pulsed field gel electrophoresis (PFGE) was applied in molecular typing of the isolates., Results: 862 water samples were collected during the study period. A total number of 77 O1 and O139 V. cholerae were isolated in 67 water samples and the positive rates were 7.77% for isolation and 26.33% for real-time PCR. Seasonal trend of positive rates by month were approximately coincident with the change of water temperature. The positive rates in the stations in urban area were higher than those in other areas. Toxigenic O139 strains were found in one station located in downstream of a marine market. Most of the O1 and O139 isolates were non-toxigenic. No trend of seasonal variation of the strains was noticed. Within these 75 isolates, 49 PFGE patterns were identified and the patterns differed widely with the similarity of 57.4% - 100%., Conclusion: V. cholerae existed as the natural habitat in estuary water of the Pearl River and showed obvious genetic diversity. Data from monitoring waters might show the separation of strains with certain seasonal association. But the crowd did not show the relationship between the infections. Results from water surveillance program might provide indicators on the appearance of cholera pathogen which might be used in assessing the environmental risk of cholera epidemics as well as the alert of cholera.

Objective: To establish molecular typing of Listeria monocytogenes isolates by pulsed-field gel electrophoresis (PFGE) for studying the epidemiologic characteristics of Listeria monocytogenes isolated from foodstuff in Guangdong province and to build up PFGE typing database of Listeria monocytogenes isolates for identifying the infectious resource of the outbreaks and other epidemiologic investigation., Methods: "Standardized Protocol for Molecular Subtyping of Listeria monocytogenes by PFGE" was followed. BioNumerics software was applied on image analysis, database establishment, comparative and corresponding analysis., Results: 107 Listeria monocytogenes isolates were typed by PFGE, 41 PFGE types were observed among the isolates. The PFGE types were dispersive among these isolates. Listeria monocytogenes isolates were most frequently isolated in raw chicken while the most PFGE types were found in this type of food. The positive rate was relatively high in cold and iced foods. Only 1-2 DNA fragment difference occurred in 26 Listeria monocytogenes isolates by PFGE, so high degree of relatedness remained among these isolates. There were unique PFGE patterns in the regions of Shaoguan and Huizhou. From time to time, a number of isolates remained close relationship., Conclusion: PFGE typing of the 107 Guangdong Listeria monocytogenes isolates demonstrated relative genetic diversity but a number of the isolates showed close relatedness.

Objective: To identify the DNA sequences of 26 beta-hemolytic group G streptococci strains isolated from the swabs of patients in a glomerulonephritis outbreak event., Methods: API20 Strep system and 16S rDNA sequencing were performed on all of the 26 isolated strains respectively. The dendrogram based on the analysis of the 16S rDNA sequences of four groups of G streptococci strains was constructed by the neighbor-joining method and boot-strap test., Results: The API20 Strep system failed to identify the strains with less than 62% of success rates. All of the 26 group G beta-hemolytic streptococci isolates were identified as Streptococcus anginosus by the 16S rDNA sequencing, with more than 97% of success rates. The dendrogram illustrated that the four groups of G streptococci strains were clustered at the same branch with Streptococcus anginosus., Conclusion: The 16S rDNA sequencing has unique advantages over the phenotypic methods. It can provide detailed information of nucleotides and identify species of beta-hemolytic G group streptococci.

In order to reveal variation and evolution of M genes of human avian H5N1 influenza strains, the M genes of human avian H5N1 strains in Guangdong were sequenced and the M genes of global strains were searched out from Internet. They were analyzed by DNAStar 5. 0 and their revolutionary speeds were studied by means of combining the epidemiological data. It was found that M1 genes of 53 H5N1 strains and M2 genes of 51 strains during 1997-2006 were homologously classified into two groups: the strains from Hong Kong during 1997 (G I) were one group and the strains from Hong Kong, Vietnam, Thailand, Indonesia, China mainland, Turkey, Iraq, Azerbaijan, Egypt during 2003-2006 (G II ) were the another group. There were 20 substitutions of amino acids in M1 gene of all strains (7.94%, 20/252), where there were 9 amino acids in strains during 2003-2006 differing from the strains in 1997, meanwhile there were 22 substitutions of amino acids in M2 gene of all strains (22.7%, 22/97), where there were 4 amino acids in strains during 2003-2006 differing from the strains in 1997. In the synonymous variation, Ks values in M1 were 26.8 x 10(-6)-42.6 x 10(-6) Nt/d, and Ka values 4.39 x 10(-6)-6.98 x 10(-6) Nt/d, where there was more rapid speed of synonymous substitution than that of replacement, which showed that there existed less human immunological pressure and negative selective pressure by biological test. Ks values in M2 were 13.1 x 10(-6)-23.4 x 10(-6) Nt/ d, and Ka values 9.1 x 10(-6)-16.2 x 10(-6) Nt/d; where the ratios of Ks to Ka was 1.0-1.6 times as there was the neutral selective pressure in TL-676-05 strain. There was an amino acid substitution of S224, N in M1 gene of strains during 2003-2006 and an increas in a glycoprotein domain NSS224-226. The secondary structure of M2 protein varied as the substitution of C50 F of eight strains from Indonesia in 2005. The strains G I did not reemerge after Hong Kong human avian H5N1 influenza event. An increase of a glycoprotein domain NSS224-226 in M1 protein during 2003-2006 might be related with virus pathogenicity. Human avian H5N1 influenza M gene evolved frequently in nature, which might have an impact on its capacity of human-to-human transmission.

Objective: To develop a real-time SYBR Green polymerase chain reaction (PCR) for detection of Vibrio cholerae serogroups O1 and O139, and to evaluate its reliability through detection of estuary water samples., Methods: O antigen rfb genes specific for O1 and O139 were used for the design of PCR primers. The real-time SYBR Green PCR system in detecting O1 and O139 specific rfb genes in one tube was developed, and its sensitivity, specificity and reproducibility were evaluated. The ability of the real-time PCR in detection of estuary water samples was compared with the routine PCR and bacteria isolation., Results: The amplification of O1 or O139 specific target gene could be detected according to the melt curve temperature of amplicons. No amplification was observed in the templates of other 10 non-cholerae vibrios. When comparing to the real-time PCR to bacteria isolation in detection of 524 estuary water samples, it showed high sensitivity, plus also positive in real-time PCR detection among all the samples in which bacteria of O1 or O139 were isolated., Conclusion: The real-time SYBR Green PCR could be used as the first step of rapid environment screen of V. cholerae in water samples thus might enhance the efficiency of isolation in screening of large amount of water samples.

Objective: To investigate the diagnosis and treatment of the complications in patients after laparoscopic adjustable gastric banding (LAGB) procedure., Methods: Retrospectively analyze the data of the 23 patients who received the LAGB procedure from June 2003 to November 2004., Results: Of the 23 LAGB operations, 3 (13%) cases of vomiting and nausea, 1 (4.3%) case of access-port infection and 5 (21.4%) cases of food intolerance occurred. One band (4.3%) and one injection reservoir (4.3%) displaced and were removed by laparoscopy. No death and thrombo-embolism occurred., Conclusions: The diagnosis and treatment of complications after LAGB in morbid obesity was special, if managed properly, the result would be satisfactory.

Objective: To observe the pathological changes and morphological alterations of ECV304 cells after the infection by herpes simplex virus type 2 (HSV-2) in vitro., Methods: Passaged ECV304 cells were infected with HSV-2, TCID50 and morphological changes were observed by optical microscopy and tissue staining., Results: One day after HSV-2 infection, swelling, rounding, and increase of thickened cytoplasmic granules occurred in the ECV304 cells, and on day 2, cell fusion was observed with weakened nuclear staining., Conclusion: ECV304 cells mostly undergo necrosis after HSV-2 infection without obvious evidence of cell apoptosis.

Objective: To investigate the mechanisms for the cytopathic effect (CPE) of human cytomegalovirus (HCMV) in ECV304 endothelial-like cells., Methods: PCR and indirect immunofluorescence were used to detect HCMV infection by examining immediate-early (IE) gene and protein expression of the virus in ECV304 cells. Phase-contrast and electron microscopies were performed to observe the morphological changes of the infected and uninfected cells, and DNA ladder analysis and flow cytometry were carried out to study HCMV-induced cell apoptosis., Results: In HCMV-infected ECV304 cells, cytopathic effects were first observed at approximately 72 h post-infection. The cells with CPE changes exhibited detachment from the monolayer, cell rounding and shrinkage. The expression of the IE gene was detected. Chromatin condensation and nuclear fragmentation along with dramatic changes of the mitochondria were observed by electron microscopy at 96 h post-infection. Cellular DNA fragmentation was observed in the infected cells, which had cells apoptotic rates of 4.1% and 45.7% at 96 h and 144 h post-infection, respectively., Conclusion: HCMV can induce apoptosis of ECV304 endothelial-like cells.

Objective: To compare the immunity of morbid obesity (MO) before and after laparoscopic adjustable gastric banding (LAGB)., Methods: 15 cases, with a mean body mass index (BMI) of 35.8 kg/m(2), were treated by LAGB from Jun. 2003 to Oct. 2003 in our department. Patients' immune parameters were determined preoperatively and 1, 3 and 6 months postoperatively. 15 cases with a normal BMI (23.6 kg/m(2)) were set as controls., Results: Before surgery, the MO had a significant lower level of CD(4)(+), CD(4)(+)/CD(8)(+) and a higher level of serum interleukin-2 (IL-2), Interleukin-6 (IL-6) than the controls (P < 0.01). There was a significant reduction of weight and BMI 6 months postoperatively (P < 0.01). At the same time, CD(4)(+) increased and serum IL-2 decreased significantly. But CD(4)(+)/CD(8)(+)and serum IL-2, IL-6 were still abnormal compare to the controls., Conclusions: MO may combined with an abnormal immunity. But after enough weight loss induced by LAGB, it can be partly reversed.