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Objective To investigate the genotypes and epidemic of metallo-β-lactamase-(MBL )-producing Pseudomonas aeruginosa (P .aeruginosa)in Changsha.Methods P .aeruginosa isolated from seven comprehensive hospitals in Changsha were collected and performed identification and antimicrobial susceptibility testing,pheno-types of MBL were detected with EDTA-disk synergy test and E-test,genotypes were determined by polymerase chain reaction (PCR),homology analysis were conducted by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR).Results Preliminary screening by EDTA-disk synergy test and E-test showed that only 10 of 81 iso-lates were strong positive;PCR result showed that 18 isolates were positive for MBL,11 of which were IMP-9-type MBL,1 was IMP-1-type,and 6 were VIM-2-type.SIM,SPM,GIM,and NDM-1-types were not found.ERIC-PCR showed that 12 strains of IMP-producing P .aeruginosa has multiple types,6 VIM-2-producing strains were of the same type.Conclusion IMP-9 and VIM-2 are main genotypes in P .aeruginosa in Changsha.
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ObjectiveTo study the characteristics of the distribution and drug resistance ofAcinetobacter baumannii, and the epidemiology of the main strains among wards and hospitals, and to investigate the role of outer membrane protein in producing resistance against carbapenems.Methods 145Acinetobacter baumannii strains were collected from July 2013 to July 2014 from Huangdao Hospital Affiliated to Qingdao University and 401st Army Hospital. Antimicrobial susceptibility test was carried out with K-B disk diffusion method. Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) was used for DNA typing and test of homology. The carO gene of outer membrane protein was amplified by PCR, and the outer membrane proteins were extracted by ultrasonication and ultracentrifuge method from 30 randomly selected carbapenem-resistantAcinetobacter baumannii and 17 carbapenem-sensitive strains. Sodium dodecyl sulfate-polyacrylamide gel electropheresis (SDS-PAGE) was used to analyze the expressions of outer membrane proteins.Results 145Acinetobacter baumannii strains were generally resistant to 16 common antimicrobial agents, with the highest susceptibility rate of 79.3% for minocycline, followed by susceptibility rate of 40.7% for amikacin. There were 128 carbapenem-resistant strains (resistance rate of 88.3%), 137 multidrug-resistant strains and 126 extensively drug-resistant strains. The detection rates of carO gene were 97.7%(125/128)and 17.6%(3/17) in carbapenem-resistant and sensitive strains respectively. Around position of relative molecular mass 47 000, 16 of 17 sensitive isolates were expressed this protein, while 20 of 30 resistant ones were detected nothing or fade; 13 of 17 sensitive isolates were expressed around position of relative molecular mass 37 000 and 29 000 while 25 were detected nothing or fade around position of relative molecular mass 37 000 and 23 were detected nothing or fade around position of relative molecular mass 29 000 in 30 resistant ones. 145Acinetobacter baumannii were classified into 8 types based on ERIC-PCR electrophoresis patterns, and the major prevalence types were type A (71 strains) and type E (37 strains).Conclusions Drug resistance of clinically isolatedAcinetobacter baumannii is a serious problem in two hospitals; drug-resistant strains are spread and epidemic among wards and hospitals. The carO gene of outer membrane protein is widespread in carbapenem-resistantAcinetobacter baumannii. The loss or fading of outer membrane protein may play an important role inAcinetobacter baumannii resistance to carbapenems drugs.
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Objective To investigate the characteristics of intestinal flora in infants with different feeding patterns.Methods Sixty-two cases of health infants(30-120 d)were divided into 4 groups according to their feeding patterns:breast feeding,imported powder milk feeding,domestic powder milk feeding and mixed feeding.Samples of their fresh feces in each group were collected and divided into sections equally:the bifidobacteria were isolated in anaerobic box and the number was counted for one section;for the other section,total DNA of intestinal flora was extracted and enterobacterial repetitive intergenic consensus (ERIC) fingerprints were amplified with the method of ERIC-PCR.After that,the specific bands observed in different groups were cloned and sequenced and alignmented.Results The colonies of bifidobacteria were more in breast feeding and mixed feeding groups[(9.10 ± 1.33) cfu/g;(8.62 ± 1.35) cfu/g]than those in domestic powder milk feeding and imported powder milk feeding groups[(7.62 ± 1.22) cfu/g;(7.32 ± 0.80) cfu/g,t =3.23,P ＜ 0.05];while there was no significant difference between breast feeding and mixed feeding groups,and between 2 powder milk feeding groups.Two specific bands were found from the ERIC fingerprints (A:1 100 bp mainly in breast feeding,domestic powder milk feeding and mixed feeding groups;B:1 000 bp mainly in imported powder milk feeding group).Sequencing and analysis of Basic Local Alignment Search Tool showed that homologous bacteria of A and B fragments were bifidobacterium longum.The encoding protein of A fragments might be related to the enzymes of carbohydrate metabolism,and B fragments were related to the enzymes of protein metabolism.Conclusions The colonies of bifidobacteria in intestinal tract are more in breast feeding and mixed feeding infants than those in formula feeding groups.The distribution of intestinal flora in domestic powder milk feeding infants is more similar to that of the breast feeding infants.
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Shigella spp are Gram-negative, anaerobic facultative, non-motile, and non-sporulated bacilli of the Enterobacteriaceae family responsible for "Shigellosis" or bacillary dysentery, an important cause of worldwide morbidity and mortality. However, despite this, there are very few epidemiological studies about this bacterium in Brazil. We studied the antibiotic resistance profiles and the clonal structure of 60 Shigella strains (30 S. flexneri and 30 S. sonnei) isolated from shigellosis cases in different cities within the metropolitan area of Campinas, State of São Paulo, Brazil. We used the following well-characterized molecular techniques: enterobacterial repetitive intergenic consensus, repetitive extragenic palindromic, and double-repetitive element-polymerase chain reaction to characterize the bacteria. Also, the antibiotic resistance of the strains was determined by the diffusion disk method. Many strains of S. flexneri and S. sonnei were found to be multi-resistant. S. flexneri strains were resistant to ampicillin in 83.3 percent of cases, chloramphenicol in 70.0 percent, streptomycin in 86.7 percent, sulfamethoxazole in 80.0 percent, and tetracycline in 80.0 percent, while a smaller number of strains were resistant to cephalothin (3.3 percent) and sulfazotrim (10.0 percent). S. sonnei strains were mainly resistant to sulfamethoxazole (100.0 percent) and tetracycline (96.7 percent) and, to a lesser extent, to ampicillin (6.7 percent) and streptomycin (26.7 percent). Polymerase chain reaction-based typing supported the existence of specific clones responsible for the shigellosis cases in the different cities and there was evidence of transmission between cities. This clonal structure would probably be the result of selection for virulence and resistance phenotypes. These data indicate that the human sanitary conditions of the cities investigated should be improved.