Carriage prevalence and susceptibility to penicillin of streptococcus pneumonia isolated from healthy children under 5 years old

Background: S.pneumoniae is a significant cause of respiratory tract infections in children under 5 years old. More strains of S.pneumoniae show less susceptibility to penicillin, and antibiotic commonly used in the treatment of pneumococcal infections. Objectives: To identify the carriage prevalence and susceptibility to penicillin of S.pneumonia isolated from children under 5 years old. Subject and Method: The study included 823 children under 5 years old living in Ba Vi, Ha Tay. Culture, bacterial identification and antibiogram by E- test have been applied in this study. Results: 51.4% of nasopharyngeal samples had S.pneumoniae. The prevalence of S.pneumoniae isolated resistant and intermediate to penicillin were 15.5% and 64%, respectively. Resistance prevalence of streptococcal isolates in children older and younger than 2 years of age were 14.1% and 17.3%, respectively. Conclusion: Approximately 80% of S.pneumoniae was non-susceptible to penicillin. There is an immense requirement to monitor the antibiotic susceptibility of S. pneumonia and to have prompt recommendations for treatment.

Development and completion of the DNA extraction procedure to directly detect diarrheagenic Escherichia coli isolates

Background: It is important to diagnosis and properly treat patients with diarrhea is having a highly sensitive and specific technique to rapidly identify the caused bacteria, especially Diarrheagenic Escherichia Coli (DEC) isolates. Objectives: To develop and complete the bacterial DNA extraction procedure and optimize the DNA concentration for multiplex PCR for DEC. Materials and method: 7 reference strains of DEC and 10 fecal samples taken randomly were tested using DNA extraction and PCR techniques. Results. A bacterial DNA extraction procedure has been developed and optimized. This is a simple process and does not require expensive equipment. The test result is available after 90 \u2013 100 minutes. The minimum DNA content required for PCR to give positive results is 100ng per reaction. Conclusion: The development and completion of DNA extraction procedure plays an important role in early detection of DEC in fecal samples and serves as a base for further research on diarrheagenic bacteria.

Carriage prevalence and distribution of virulence genes of diarrheagenic Escherichia coli isolated from healthy children under 5 years of age in community

Introduction: Diarrheagenic Escherichia Coli (DEC) is getting more and more important as a cause of diarrhea in children under 5 years of age. Detection of DEC prevalence and distribution of their virulent genes plays an important role in prevention and treatment for E.coli-related diseases and vaccine development. Objectives: This study was conducted with the aim to detect DEC prevalence and the distribution of virulent genes of DEC isolated from healthy children under 5 who were living in the community. Subjects and method: 826 children under-5 living in Ba Vi District, Ha Tay Province were selected. Polymerase chain reactions using specific primers to virulent genes of DEC were used. Results. The study found that the prevalence of DEC was 9.8%, among this EAEC accounted for 3.1%, EHEC 1.8%, EIEC 0.1%, EPEC 1.1%, ETEC 0.1% and two DECs 3.5%. Combinations of virulent genes of EHEC and EHEC+ETEC accounted for 50% of total virulent genes. Conclusion: Five types of DEC were isolated from subjects with the prevalence of 9.8%. The most common virulent genes were combinations of EHEC and ETEC. Further studies are needed to investigate the transmission pathway of DEC in children living in the community.

Rapid detection of fungal keratitis by semi-nested PCR

Background: Fungal keratitis is a serious ocular infection that can cause corneal scarring and blindness. Currently, diagnosis of fungal pathogens remains a difficult problem. Objectives: To investigate the application of semi-nested PCR targeted ITS genes for detection of fungal agents causing keratitis. Material and method: Ten identified fungal strains, 4 bacterial strains, 20 scraping samples from patients with suspected fungal keratitis and 2 scraping samples from patients with suspected bacterial keratitis were tested using semi-nested PCR. Results: Semi-nested PCR showed positive results for the samples of identified fungal strains and for the 20 scraping samples from patients with suspected fungal keratitis. Neither samples of bacterial strains nor scraping samples from suspected bacterial keratitis patients gave positive PCR results. Conclusion: Semi-nested PCR is a robust tool for specific and rapid detection of fungal agents causing keratitis.

Perfection of method for direct DNA extraction of Shigella and EIEC from fecal samples

Background: PCR technique combined with culture isolates is used commonly to detect bacteria that can cause diarrhea from clinical samples. Direct DNA extraction which is a simple, fast and effective method is very important in the rapid diagnosis of bacterial pathogens from fecal samples. Objective: Perfection of method for direct DNA extraction of Shigella and EIEC from fecal samples. Subjects and method: EIEC ATCC 43893, E. coli ATCC 11775 was used for positive and negative controls. Extracted DNA would be used for PCR. Results: The method for direct DNA extraction of Shigella and EIEC from fecal sample had been successfully developed. It was a simple, rapid, cheap and applicable method. Conclusion: The method for direct Shigella/EIEC DNA extraction had been successfully developed and it was very helpful in early detection of diarrheal-induced bacterial pathogens.

Detection of Virulent Gene Distribution of Diarrheagenic Escherichia Coli (DEC)

Introduction: There are 5 identified DEC including EAEC, EHEC, EIEC, EPEC and ETEe. Virulent genes (for adherrnee, toxin, antibiotic resistance ...) play important roles in pathogenesis of DEe. Detection of DEC is very important in diagnosis, epidemiology survey and vaccine development. \r\n', u'Objectives: Detection of virulent gene distribution of DEC and non - DEe.\r\n', u'Object and methods: 161 strains of DEC (EAEC, EIEC, EPEC, TEC) and 100 strains of non - DEC were subjected to this study. PCR with specific primers were used to test these genes. \r\n', u'Results: EAEC that accounted for 50% of DEC, was identified and isolated. Aap gene was the highest prevalence in EAEC (96.5%), followed by aggR (79.1 %) and astA (60.5%). 37.2% of the strains harbor all three genes. None of strains had PCR results negative for these 3 genes. ETEC, EPEC and EIEC had aap, and astA gene at the prevalence from 7% to 72.7%. The highest prevalence of aap was seen in EIEC 72.7%), aggR in EIEC (45.5%), and astA in ETEC (50%). 14% of non - DEC had aggR and more than 30% of E. coli had aap and astA gene. \r\n', u'Conclusion: EAEC is prevalent at 50% among Diarreagenic E. coli. Aap is the most prevalent and the most commonly seen among EAEC isolates. The other three genes are at different prevalence. The findings contribute towards the vaccine development against diarrhea caused by E. coli. \r\n', u'

Detection of aap, aggR, and astA in strains off enteroaggregative E.Coli

Background: Aap, aggR, astA have been found to play important roles in diarrheal pathogenecity of enteroaggregative (EAEC). Objective: (1) To determine the distribution of aap, aggR, astA in EAEC. (2) To compare the distribution of aap, aggR, astA in EAEC isolated from healthy children and children with diarrhea. Subject and methods: \r\n', u'86 strains of EAEC isolated from children under 5 living in Hanoi, have been screened by PCR with specific primers. Results: Aap was found at the highest prevalence of 96.5%, aggR (79.1 %) and astA (60.5%). 37.2% of strains had all of aap, aggR and astA. None of strains was shown negative with these genes. Distributive rate of aap, aggR, astA in EAEC strains isolated from children with diarrhea was higher than EAEC strains isolated from healthy children. However, this difference was not statistically significant. Nearly 100% of the EAEC strains isolated from children with diarrhea had aap gene. The rate of aggR and astA was lower. Among children aged 0-24 months and children aged 25-60 months, distribution of these three genes was not different with statistical significance Conclusion: This finding has contributed to understanding the distribution of aap, aggR and astA of EAEC\r\n', u'\r\n', u'

Detection of aaP, aggR, and astA in strains of ETEC, EPEC, EIEC and non-diarrheagenic E.coli

Background: aaP, aggR, and astA have been found to play important roles in diarrheal pathogenecity of EAEC. They may be exist in other diarrheagenic E.coli (DEC). Objectives: To determine the distribution of aaP, aggR, and astA in ETEC, EPEC, EIEC and non-diarrheagenic E.coli. Subjects and method: 75 strains of ETEC, EPEC, EIEC and 100 non-DEC have been screen by PCR with primers specific toaaP, aggR, and astA. Results: aaP, aggR, and astA have been seen in DEC with the prevence from 7 to 72,7%. The highest prevence was in EIEC, 72,7% for aap; 45,5% in EIEC for aggR; and 50% in ETEC for astA. 14% of non-DEC harbored aggR and more than 30% harbored aap and astA. Conclusion: This finding has contributed to understanding the distribution of aap, aggR and astA in ETEC, EPEC, EIEC and non-DEC as well.

Detection of common extended \ufffd?spectrum \xdf \ufffd?Lactamase genes in EAEC strains

Background:blaTEM, bla SHV, blaCTX \ufffd?M, blaOXA genes encode for extended spectrum \u03b2 \ufffd?lactamases resistance to broad \ufffd?spectrumcephalosporins. Many species belonging the family Enterobacteriaceae possess these genes. Objectives: To determine the distribution of blaTEM, bla SHV, blaCTX \ufffd?M and blaOXA genes in enteroaggregation E.coli (EAEC) strains. Subjects and method: 67 EAEC strains causing diarrhea and 18 strains isolated from healthy children were screened by PCR with primers specific to blaTEM, bla SHV, blaCTX \ufffd?M \ufffd?1and blaOXA genes. Results: The prevalence of ESBL genes in diarrheagenic EAEC strains and those isolated from healthy children were 83.6 and 72.2 %, respectively. The highest prevalence blaTEM gene (82% in diarrheagenic EAEC strains and 72.2% in isolated from healthy children) was followed by that of blaOXA gene (11.9 and 11.1% in two EAEC groups). Only 2 strains possess blaSHV gene. The blaCTX \ufffd?M \ufffd?1 was not detected in any EAEC strain. Conclusion: our findings have not only provided additional understanding of the distribution of blaTEM, bla SHV, blaCTX \ufffd?M - 1 and blaOXA genes in EAEC strains but also have a given significance in selecting antibiotics for treatment.

The role of enteroaggregative escherichia coli in children with diarrhoea in Hanoi

Background: Enteroaggregative Esherichia coli (EAEC) is a bacterium that can cause diarrhea. Enteroaggregative Esherichia coli (EAEC) has been one of important diarrheagenic E. coli. It is necessary to evaluate the role of EAEC in causing diarrhea in children. Objectives: The purposes of this study are to determine the prevalence \r\n', u'of EAEC in children with and without diarrhea and to evaluate the clinical symptoms of diarrhea caused by EAEC. Subjects and method:These 836 children living in Hanoi including 587 children with diarrhea and 249 controls have been selected for the study. Polymerase Chain Reaction in combination with the conventional method have been used to detect EPEe.They were treated at Saint \ufffd?Paul Hospital, Thanh Nhan Hospital and National Hospital of Pediatrics. Results: EAEC strains have been detected with the prevalence of 11.6% in children with diarrhea and of 7.2% in the controls. It shows a correlation of EAEC with diarrhea in children less than 2 years of age. The common clinical symptoms of EPEC diarrhea anT watery diarrhea, sunken, vomiting. Conclusion: Enteroaggregative Esherichia coli are attributable to about 12% of diarrheal cases in children. Watery diarrhea is the most commonly seen symptom. It would be of interest to perform further studies on diarrhea caused by EAEC in children in Hanoi. \r\n', u'

Modified triptic soy-serum-bacitracin-vancomycin (TSBV) medium in isolation of Actinobacillus Actinomycetemcomitants

A modified TSBV medium has been prepared in Vietnam. This procedure was simple, unexpensive and easy to implement in the microbial laboratories. The medium inhibited most of microbials in the stoma and facilitated the good development of actino bacillus actinomycetem comitants

Research on Actinobacillus actinomycetemcomitans and Capnocytophaga gingivitis in healthy - periodontal and periodontitis adults

200 subgingival specimens collected from 100 healthy periodontal adults of Thanhliet, Thanhtri, Hanoi, from 100 periodontitis adults of Odonto-stomatology Departments of Dongda and Thanhnhan Hospital were cultured and isolated for Actinobacillus actinomycetemcomitans and Capnocytophaga gingivitis. The prevalence of Aa and Cg in the periodontitis group is clearly different from that in the healthy periodontal one. The higher rate of Cg compared with the rate of Aa is found in female with periodontitis. Both Aa and Cg are sensitive to ampicillin, tetracycline, and chloramphenicole. Their sensitivity to erythromycin and sulfamethoxazole/ trimethoprime changes. Cg is resistant to amikacin. TSBV medium used for culturing and isolating Aa has improved to be suitable to Laboratories in Vietnam.