The study was conducted to compare the molecular differences of Haemophilus influenzae type b (Hib) strains causing meningitis in young children with H. influenzae strains causing acute upper respiratory tract infection, 44 Hib strains and 37 H. influenzae strains were analysed by pulsed field gel electrophoresis (PFGE) with SmaI restriction enzyme. The results: 44 Hib strains were mainly distributed into 4 DNA restriction patterns (PFGE patterns) whereas 37 H. influenzae strains were distributed into 22 patterns and 81% of them were not encapsulated. The genome of Hib strains causing bacterial meningitis showed less variation than that of H. influenzae causing acute upper respiratory infection. PFGE is a useful tool for epidemiological research.
Haemophilus influenza ; Child

In order to enhance the capability of antiserum production rabbits, Mycobacterium vaccae was used to stimulate rabbit’s immune system unspecifically before immunization with Haemophilus influenzae type b (Hib). The results showed that only single immunization with Hib antigen: the number of rabbits had response fulfill depended-time requirements (harvested after 1 or 6 months) varied from 30% to 70%, harvesting time for antiserum with fulfilled quantity and quality was 24 weeks (6 months) (2 courses induced immunization). Stimulating rabbit’s immune system by M. vaccae, then inducing rabbit’s immunization with Hib antigen: the number of rabbits had response fulfiling requirements varied from 71.4% to 100%; harvesting time for antiserum with fulfilled quantity and quality was 5 weeks (only after 1 course induced immunization). Sensitivity and specificity of antiserum were unchanged
Mycobacterium ; Helicobacter pylori ; Immune Sera ; Adjuvants, Immunologic

34 Haemophilus influenzae type b (Hib) strains isolated from cerebrospinal fluids (CSFs) of meningitis patients at National Hospital of Pediatrics, Hanoi, between 11/2002 and 12/2003 were biotyped, serotyped and analyzed by using PCR with specific primers, Pulsed field gel electrophoresis (PFGE) with Smal restriction enzyme. The results showed that 24 of 34 Hib strains (70.6%) belong to biotype II; 8 of 34 (23.5%) belong to biotype I. PCR patterns with capsular polysaccharide type b specified primers of the 34 Hib strains were identical. DNA restriction patterns generated by PFGE (so-called PFGE patterns) of the 34 Hib strains were mainly distributed into 2 PFGE patterns. DNA restriction patterns had close relationship to biotype. The presence of PFGE patterns of Hib strains was not related to season
Haemophilus influenzae type b ; pathogenicity ; Haemophilus influenzae

Clinical characteristics and cerebrospinal fluid abnormalities in 100 cases of confirmed B type of H.influenzae (Hib) meningititis were analysed in comparing with 105 cases of meningitis caused by other bacterial pathogens. The basic criteria for early diagnosis of Hib meningitis in under five year old children were found out. Results showed that 48.8% of cases of meningititis were due to Hib; 96% of CSF samples due to Hib had physiological change in comparing with 72.4% in meningitis due to other bacterial pathogens, in 92% there were clinical manifestations and biochemical/cytological typical changes in CSF, in 100% of cases of Hib meningitis(+), there were typical changes; 51% of cases there were positive blood culture and 47% there were Hib positive CSF and blood culture concurrently
Meningitis ; Child ; Haemophilus influenzae

Seventy-nice pediatric patient - family pairs were detected for Hib or Hib-antigen. The study also examined 22 pairs of H. influenzae strains isolated from CSF of patients and from upper respiratory tract of the family members of the patients to determine serotype, biotype, presence of Beta-lactamase, PCR with Hib-specified primers, and PFGE with SmaI restriction enzyme. The results showed that 44.4% of the patients` families had Hib carriers; all of 22 H. influenzae isolated pairs from patients and their families had serotype b; 17 of 22 pairs had characteristics of biotype II; 16 of 22 pairs had Beta-lactamase; and 9 of 22 pairs had both the PCR pattern and PFGE pattern. Close contact with Hib carriers was a factor of Hib meningitis contagiousness in children under 5 years of age
Family ; Haemophilus influenzae type b ; Meningitis ; child

Some techniques of detection of Hib were compared, including classic techniques such as bacterial culture and modern techniques such as PCR method. The results were as follows: 21% (+) culture with Hib compared to the total of clinically diagnosed cases, Hib-latex agglutination with 95% sensitivity and 99.6% specificity, counter immunophoresis assay to detect Hib by 97% sensitivity and 100% specificity. PCR increased the number of positive cases of Hib meningitis by 42.8% compared to culture alone. Blood culture gave a highly significant value to diagnose (51% Hib-possitive culture)
Haemophilus influenza type b ; Meningitis ; methods ; diagnosis

Background: Food-born bacteria can be present in raw materials or contaminated foods during process and storage. Shrimp paste is a popular food in Viet Nam, but there are no studies on the hygiene and safety of this food. Objectives: To identify the microbial contamination of commercial shrimp paste available in Ha Noi City. Materials and method: A total of 50 shrimp paste samples were collected randomly from markets around Ha Noi City. Enumeration and isolation methods were used to determine the microbial contamination in these samples. Results: 100% of the samples were contaminated with Clostridium perfringens and Candida albicans. 10% of samples were contaminated with Coliform. Other pathogenic bacteria, including Escherichia coli, Salmonella, Staphylococcus aureus, Vibrio parahaemolyticus and Vibrio cholerae were not found in shrimp paste samples. Conclusion: Evaluation of microbial contamination in popular foods such as shrimp paste should be done regularly to prevent food-born diseases in the community.
Microbial contamination ; Food safety.

Background:The kit Crystal VC is a Lateral Flow Imunochromatographic test for the qualitative determination of Lipopolysacharide (LPS) antigen of both V cholerae 01 and 0139, from stool specimens, using monoclonal antibodies specific to V. cholerae 01 and 0139 LPS. It does not include culturing the specimen and is performed without the need for sophisticated laboratory equipment. \r\n', u'Objectives: To evaluate the dipstick kit for detection of V. cholerae 01. Subjects and methods: A total of 65 stool specimens from diarrhea patients were tested to determine V. cholerae 01 by Crystal VC kit. \r\n', u'Results: The sensitivity of the 01 dipstick compared to culture was 93.7%, with a specificity of 87.7%. Crystal VC kit is simple, sensitivity, specific and does not require culturing procedures, making it suitable for direct detection of V. cholerae in clinical specimens. Also, the test only requires 10 minutes to complete.\r\n', u'Conclusions: The dipsticks test may be helpful in confirming clinically suspected cholera cases, especially during the start of an outbreak. Once a cholera outbreak has been confirmed, large scale preventive measures could be mobilized to minimize morbidity and mortality. \r\n', u'
Dipstick kit ; vibrio cholerae 01

Background: Diarrhea is a leading cause of death in children under 5 years old, especially in developing countries. About 12.600 children die because of diarrhea everyday in Asia, Africa and Latin-America. Objective: To identify the main organism that causes diarrhea in children under 5 years old. Subject and Method: The etiology agents of diarrheal children under 5 years old admitted to the Pediatric Hospital in Hai Phong city were studied in the period from September 2006 to August 2007. A total of 968 children were examined for diarrheagenic Escherichia coli (DEC), Salmonella, Shigella, Vibrio, Aeromonas, Campylobacter, these pathogens as being significant bacteria associated with diarrhea. A total of 212 out of 968 cases were positive for bacteria. Result: The main pathogens were diarrheagenic Eschierichiacoli 153 (15.7%), Salmonella 12 (1.24%), Shigella 32 (3.3%). Vibirio paraheamolyticus 1(0.1%), Aeromonas 8 (0.8%), Campylobacter 6(0.6%) from rectal swabs and no Vibrio cholerae was found. The multiplex PCR assays for the identification of DEC was developed. DEC was classified into 6 categories with frequencies of EPEC 3.9%, ETEC 4.4%, EIEC 0.6%, EAggEC 6.7%, DAEC 0.1%, no EHEC was identified. Conclusion: An analysis of incidence of enteropathogens with respect to seasonal variant demonstrated that the frequencies of isolation of etiology agents mainly in July, August and September. This study also showed that diarrheagenic- Escherichia coli is the main organism causing diarrhea in children under 5 years old.
Diarrhea ; enteropathogenic bacteri ; diarrheagenic Eschierichiacoli

Background: Classification of vibriophages has been applied for epidemiological surveillance of cholera, but in Vietnam, there was virtually no knowledge about it. It is very important to determine whether the strains have common origin or different origins.Objectives: To classify vibriophages isolated from environmental surface water samples in Thai Binh in order to monitor cholera outbreaks. Subjects and method: Three vibriophages (84, 87, and 811) were collected from surface water samples in Thai Binh in 2006. Electronic microscopy was used to compare the size and morphology of Vibrio phages. Also, the structures of genomic DNA of vibriophages were compared by hind III digestion pattern and Southern blotting. Results: Vibriophages S4 and S11 isolated from Thai Binh were similar to kappa phage (a phage produced by V. cholerae 01 EI Tor strain), phage IV (a phage produced by V. cholerae 01 classical strain) in term of morphology and genome and were the same shape and DNA dimension of phage 1823 isolated from V. cholerae O139 strain in India and Bangladesh. Conclusion: Phage 84, 81 isolated from Thai Binh were new kinds of vibriophage isolated in Viet Nam. These findings were very useful for supervising and controlling cholera outbreaks in Vietnam.
Classification ; vibriophage ; environment surface water