Genotype features of norovirus associated with acute gastroenteritis through sentinel surveillance in Guizhou Province, 2011 / 病毒学报

To study the genotype of Norovirus associated with acute gastroenteritis in Guizhou Province 2011, the patients' fecal specimens were collected from the Guizhou Province People's Hospital in the period of May to December 2011. Noroviruses in specimens were detected by a real-time reverse transcription polymerase chain reaction (Real-time RT-PCR). VP1 genes of norovirus-positive strains were then cloned and sequenced. Out of 70 clinical samples, the positive rates for norovirus G I (1 strain) and G II (34 strains) were 1.43% and 48.57, respectively. The VP1 sequencing results of seven norovirus G II showed thatthree strains were genotype G II . 4 and four strains were genotype G II . 3 Those genotype GIL . 4 strains were new variants (GII . 4 2011),closest to GII . 4 2006b variant. One amino acid appeared back mutation. Those genotype G II . 3 strains were divided into 2 gene clusters. One cluster was closest to Korean strain (HM635118) and Shanghai strain(GU991355). One cluster was closest to Japaness strain (AB629943) and 2007 Indian strain (EU921389), Four amino acids appeared back mutations.

Identification and genetic characteristics on the bacteria isolate from a case of human Brucellosis in Guizhou province / 中华流行病学杂志

<p><b>OBJECTIVE</b>A suspected Brucella (B.) strain(GZZA), isolated from a case of anti-Brucella antibody positive patient was identified and its' genetic characteristics was analyzed, to provide etiologic basis for the confirmation of patient in Guizhou province.</p><p><b>METHODS</b>Conventional methods and polymerase chain reaction(PCR)were used to identify the bacteria strain, with genetic characteristics analyzed by MLVA-16.</p><p><b>RESULTS</b>The bacteria strain was identified as B. melitensis biovar 3 under the conventional and PCR methods. Results from the MLVA-16 analysis indicated that the bacteria strain was closely clustered with B. melitensis biovar 3, and differences of repeated numbers at VNTR loci bruce42, bruce04, bruce09 and bruce16 were also displayed.</p><p><b>CONCLUSION</b>Both traditional and molecular methods to identify one bacteria strain isolated from the human patient as B. melitensis biovar 3 and the genetic characteristics of the strain was closely related to that of B. melitensis biovar 3. Differences of repeated numbers at part of VNTR loci were also showed. The results of this study provided etiologic evidences for the confirmation of Brucella infection of the patient, also providing scientific basis for the control and prevention of Brucellosis in Guizhou province.</p>

Fever monitoring program in areas with high incidence of typhoid and paratyphoid fever in Guizhou province / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the incidence rates of both typhoid fever and paratyphoid fever in the high prevalent areas of Guizhou province so as to provide evidence for the development of programs on comprehensive intervention and effectiveness evaluation.</p><p><b>METHODS</b>Six townships in Pingba county were selected as intervention areas while six townships in Kaiyang county were taken as control. All hospitals and clinics were classified into A, B and C types according to its level and the capacity of the blood culture. Surveillance on typhoid and paratyphoid fever was conducted based on all population and all hospitals, clinics and county CDCs among the patients with unknown fever.</p><p><b>RESULTS</b>In the surveillance area in those two counties, there were 12 944 blood samples from patients with unknown fever which have been tested and cultured. Among them, 200 strains of Salmonella including 16 typhoid strains, 184 paratyphoid A strains were identified, with the total positive rate as 1.55%. The positive rate before the intervention program was higher than the after. The detection rate was 1.91% in the type A hospitals. 39 strains of Salmonella have been cultured from 2039 samples which accounting for 19.50% (39/200) of the total strains. 4315 blood samples were cultured at the 'Class B' sites which isolated 82 strains of Salmonella, accounting for 41.00% (82/200), with a detection rate as 1.90%. 6590 samples were cultured at the 'Class C' sites, which identified 79 strains of Salmonella, accounting for 39.50% (79/200), with a detection rate as 1.20%. The detection rate was much higher before the use of antibiotics than after using them (P < 0.05). The annual peak time of positive detection was in spring and fall. The outbreaks or epidemics often appeared in the same places, with farmers, students as the high-risk populations. Symptoms of both typhoid and paratyphoid fever were not typical.</p><p><b>CONCLUSION</b>Typhoid and paratyphoid monitoring programs which covered primary health care institutions in the high incidence area seemed to be effective in reflecting the pictures as well as the burden of both typhoid and paratyphoid.</p>

Etiologic diagnosis and analysis of the first case of human brucellosis in Guizhou province / 中国地方病学杂志

Objective To etiologically diagnose and analyze a patient with suspected cases of brucellosis,and to provide a experimental basis for the confirmation of the first case of human brucellosis in Guizhou province.Methods Conventional and molecular techniques [genus specific Brucella surface protein 31 PCR (BCSP31-PCR)and Brucella suis species-specific PCR (AMOS-PCR)] were used to identify suspicious bacteria strains isolated from the suspected patient of brucellosis.Results The results showed that the Brucella suspicious colonies were identified as Brucella melitensis biotype 3 using conventional tests and were further identified as Brucella spp.by genus specific Brucella surface protein 31 PCR (BCSP31-PCR) and classified as Brucella melitensis with Brucella abortus,Brucella melitensis,Brucella ovis,Brucella suis species-specific PCR(AMOS-PCR).Conclusions Laboratory diagnostic results show that the bacteria strain isolated from the suspected patient of brucellosis is Brucella melitensis biotype 3.It is the first case of human brucellosis in Guizhou province.

Analysis of the genetic differences in the nucleoprotein between rabies virus and its vaccine strains in Guizhou province from year 2005 to 2010 / 中华预防医学杂志

<p><b>OBJECTIVE</b>This study was to explore the differences in the nucleoprotein gene between rabies virus (RABV) and its vaccine strains in Guizhou province from year 2005 to 2010.</p><p><b>METHODS</b>Samples from 4 rabies patients and cerebral tissue samples of 28 rabies infected dogs were collected from different districts in Guizhou province between year 2005 and 2010. Direct Immunofluorescence Assay (DFA) and RT-nested PCR assay were applied to detect the overall length of N gene sequence. Meanwhile, based on the comparison between the homology and phylogenetic tree, the differences in N gene sequence between the prevalent RABV and the RABV vaccine strains collected from NCBI database in these years.</p><p><b>RESULTS</b>According to DFA and RT-nested PCR assay, the antigen and nucleic acid of the 21 dogs and 4 human samples were both confirmed positive; whose full length of N gene sequences were both 1353 bp. The homological analysis showed that the 25 strains of RABV virus and the RABV type I virus stored by GenBank database shared a high homology in N gene nucleotide and amino acid sequences, which were 89%-100% and 98%-100%, respectively. Besides, the homology between the 25 strains of RABV virus and its vaccines in nucleotide and amino acid sequences were separately 86%-95% and 96%-100%. The N gene of vaccines for livestock shared the highest homology with HEP-Flury strain in the nucleotide and amino acid, which were 88%-89% and 98%-99%, respectively. The vaccines for human use showed its greatest homology with the CTN strain in nucleotide (86%-100%) and amino acid (96%-100%). The phylogenetic tree analysis indicated that the 25 strains of RABV virus, RABV type I virus and the CTN vaccine strains constituted one individual cluster, which was least different from the CTN vaccine for human use.</p><p><b>CONCLUSION</b>The prevalent RABV virus, the vaccine HEP-Flury for livestock and the vaccine CTN for human use were found to be highly similar in N gene expression in Guizhou province from 2005 to 2010.</p>

Molecular typing of Leptospira interrogans strains isolated from Rattus tanezumi in Guizhou Province, Southwest of China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To identify and type three leptospires isolated from Rattus tanezumi in Guizhou Province by using three molecular techniques (PFGE, MLVA, and MLST), reveal the molecular characteristic of causative agents of local leptospirosis and evaluate these three molecular methods based on their detection resolution and efficiency.</p><p><b>METHODS</b>Three Leptospira strains were isolated from the kidney of Rattus tanezumi and cultured with EMJH medium. PFGE, MLVA, and MLST assays were applied to type the three strains isolated from Rattus tanezumi in Guizhou Province.</p><p><b>RESULTS</b>PFGE, MLVA, and MLST typing showed that the three leptospiral isolates matched with leptospiral serogroup Icterohaemorrhagiae serovar Lai. The findings of the genotyping methods were consistent. MLVA and MLST defined genotypes, whereas PFGE allowed the recognition of additional subgroups within the genotypes, and the findings of molecular typing were also consistent with those of traditional techniques.</p><p><b>CONCLUSION</b>Three leptospiral isolates from Guizhou Province matched with leptospiral serogroup Icterohaemorrhagiae serovar Lai, and PFGE, MLVA, and MLST, as reliable molecular techniques for identifying and typing of Leptospira interrogans, would contribute to the active surveillance, outbreak investigation and source tracking for leptospirosis in Guizhou Province.</p>

Analysis on nucleoprotein gene sequence of 25 rabies virus isolates in Guizhou Province, China / 病毒学报

To analyze 25 nucleoprotein gene (N gene) sequences of rabies viruses circulating in Guizhou province during 2005-2010, China, and to explore the epidemic characteristics and the probable mutant of rabies in Guizhou Province. Rabies virus RNA in human brain tissues, human saliva, and domestic dog brain tissues derived from different prefectures of Guizhou Province were detected with RT-nested PCR, and the amplified products were then sequenced. Bioinformatics software was used to determine the genetic characteristics of these rabies viruses. The sequences of N gene of 25 Guizhou provincial isolates were identical with homogeny between 97.5% - 99.3% and 98.4% - 99.8% at nucleotide and deduced amino acid level, respectively, while the identities between them and isolated strains from other province of China were 88% - 99.1% and 88% - 99.7%. There were several amino acid substitutions in the nucleoprotein of 25 Guizhou isolates compared with the known genotype 1 isolates. The analysis of phylogenetic tree of 25 Guizhou isolates was demonstrated to be genetically divided into two groups, indicating that the virus presented a unique characteristics in geographic distribution and in a time dependent-manner. And phylogenetic tree of 25 Guizhou isolates and 7 genotype 1 strains isolated from other Province of China was also divided into two groups, which were further composed of several subgroups, respectively. From these observations, the rabies viruses derived from Guizhou province were still genotype 1. These isolates of rabies virus were diverged from the strains isolated from other provinces in both gene sequences and deduced amino acid sequences, and these divergences were characterized in geographic distribution and in a time-dependent manner.

Molecular typing of Salmonella paratyphi A isolates from four provinces with pulse-field gel electrophoresis / 中华流行病学杂志

<p><b>OBJECTIVE</b>To analyze the molecular types of Salmonella paratyphi A strains isolated in the recent years, and to construct the standard S. paratyphi A databank in the laboratory surveillance network PulseNet China.</p><p><b>METHODS</b>S. paratyphi A isolates from 4 provinces were analyzed with the standard pulsed-field gel electrophoresis (PFGE) protocol used in PulseNet and their patterns compared. The databank was constructed with BioNumerics.</p><p><b>RESULTS</b>Eleven PFGE patterns were obtained, in which 3 predominant patterns were identifies with a similarity coefficient of 96.3%. The strains of these patterns, accounted for 86.5% of the analyzed strains, appeared in different provinces and years.</p><p><b>CONCLUSION</b>The databank of S. paratyphi A was constructed and could be used in laboratory surveillance of S. paratyphi A in PulseNet China. From the analyses on molecular typing of the isolates, data suggested that the predominant strains might cause the epidemics in different regions.</p>