Performance of different composting techniques in reducing oestrogens content in manure from livestock in a Vietnamese setting.

Steroid oestrogens (SE) are released by humans and animals into the environment. In the Mekong Delta animal excrement is directly discharged into surface water and can pollute the water. Only a few animal production sites are currently treating the excrement in either biogas plants or vermicomposting systems. The concentration of SE in manures from pigs and cattle was monitored in the Mekong Delta, Vietnam. Fresh cow faeces had an oestrogen concentration of 3.3 ng E2 eq/g dry weight. The SE concentration in effluent from biogas plants fed with animal manures was 341 ng E2 eq/L. Most of the SE were in the solid phase (77.9-98.7%). Vermicomposting reduced SE to 95% of the original input.

Clonal expansion and microevolution of quinolone-resistant Salmonella enterica serotype typhi in Vietnam from 1996 to 2004.

Salmonella enterica serotype Typhi clinical isolates (n = 91) resistant to nalidixic acid (Nal(r)) were collected from sporadic cases and minor outbreaks throughout Vietnam between 1996 and 2004. These isolates were typed and compared by four methods: Vi phage typing, PstI ribotyping, XbaI and SpeI pulsed-field gel electrophoresis (PFGE), and single-nucleotide polymorphism (SNP) analysis. The results indicated that 65% of the isolates were not typeable by Vi phage typing. In contrast, the ribotyping and, with more accuracy, the SNP analysis methods indicated that all Nal(r) isolates belonged to a single clone (ribotype 3a, haplotype H58) that was found previously and that largely consisted of plasmid-encoded multidrug-resistant serotype Typhi isolates. PFGE demonstrated the occurrence of microevolution within this clone. We identified two major combined PFGE profiles: X1-S1 and X3-S6. X3-S6 predominated between 1996 and 2002 but was replaced by X1-S1 after 2002. Nevertheless, PFGE, with a Simpson's index of 0.78, was not considered an optimal discriminatory method for investigating typhoid fever outbreaks in Vietnam. The rate of quinolone resistance increased and the rate of multidrug resistance decreased during the study period. From 2002 to 2004, 80.6% of the isolates from South Vietnam were resistant only to Nal. The mechanism of Nal resistance in most of the isolates (94%) was a mutation in the quinolone resistance-determining chromosomal region of gyrA that led to the amino acid substitution Ser83Phe. No plasmid-located qnrA, qnrB, or qnrS was detected.

Evolutionary history of Salmonella typhi.

For microbial pathogens, phylogeographic differentiation seems to be relatively common. However, the neutral population structure of Salmonella enterica serovar Typhi reflects the continued existence of ubiquitous haplotypes over millennia. In contrast, clinical use of fluoroquinolones has yielded at least 15 independent gyrA mutations within a decade and stimulated clonal expansion of haplotype H58 in Asia and Africa. Yet, antibiotic-sensitive strains and haplotypes other than H58 still persist despite selection for antibiotic resistance. Neutral evolution in Typhi appears to reflect the asymptomatic carrier state, and adaptive evolution depends on the rapid transmission of phenotypic changes through acute infections.

Endemic, epidemic clone of Salmonella enterica serovar typhi harboring a single multidrug-resistant plasmid in Vietnam between 1995 and 2002.

Salmonella enterica serovar Typhi strains resistant to ampicillin, chloramphenicol, tetracyclines, streptomycin, and cotrimoxazole, isolated from sporadic cases and minor outbreaks in Vietnam between 1995 and 2002, were typed and compared. Plasmid fingerprinting, Vi bacteriophage typing, XbaI pulsed-field gel electrophoresis, and PstI ribotyping showed that endemic, epidemic multidrug-resistant typhoid fever was due, for at least 74.1% of the isolates, to one or two clones of serovar Typhi harboring a single resistance plasmid. PstI ribotyping was used as a basic technique to ensure that a serovar Typhi expansion was clonal.

The technique of combining antibiotics in the treatment of serious infection in burn patients

In the period from Aug 2002 to Aug 2003, at the National Institute of Burn strains of S. aureus and 45 strains of P.aeruginosa were isolated from the blood of severious septicemia patients.In disk diffusion test,100% of S.aureus strains were resistant to penicillin, erythromycine, kanamycine, tobramycine, gentamycine, oxacilline, 36% in particular, resistant to vancomycine and 45% to teicoplanine. 100%,of P.aeruginosa were resistant to ticarcilline, cefoperazol, gentamycine, tobramycine and 50% were resistant to ciprofloxacine.The most common effective combinations were rifampicine+acide fusidic, or rifampicine+ vancomycine for S. aureus, and imipenem + fosfomycine or imipenem+netilmycine, or imipenem +piperacillin/tazobactam for P.aeruginosa

The sensitive of antibiotics of Pseudomonas aeruginosa strain isolated in some hospitals in Hanoi city

Pseudomonas aeruginosa is resistant many antibiotics currently, including new generation, broad spectrum antibiotics that were very effective with other bacteria. Thus, it's difficult to treat P. aeruginosa infection with these antibiotics. Author collected P. aeruginosa strains from some hospitals in Hanoi, tested with more antibiotics in order to determine antibiotic resistant rate and types, to orient some mechanisms of antibiotic resistance of P. aeruginosa. Materials is 97 strains of P. aeruginosa isolated from blood and pus of patients treated at Bach Mai Hospital and National Institute of Burn from August 2002 to November 2003. Method: disk diffusion antibiotic sensitivity testing (Kirby - Bauer test). Results: Isolated P. aeruginosa strains are multiple antibiotic resistant (8 of 16 antibiotics), especially hospital infection strains are resistant 100% of tested antibiotics. It showed the potential roles of some enzymes such as penicillinase, cephalosporinase, AAC(6), ANT(2")-1, and ANT(2") enzymes that inhibit effects of antibiotics in bacterium cell