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Antimicrobial resistance is on the rise while the number of antibiotics being brought to market continues to drop. Drug-resistant genes and drug-resistant bacteria infection have seriously threatened human health. Therefore, antimicrobial resistance presents an ongoing challenge that requires multifaceted approaches including: biomedical innovation; improved surveillance of antibiotic consumption and antimicrobial resistance generated rates; prevention of health-care-associated infections and transmission of multidrug-resistant bacteria and environmental dissemination; rapid microbiological diagnosis; and curtailed clinical and veterinary misuse. Fortunately, combating antimicrobial resistance has been highly valued and supported by the government, scientists and entrepreneurs of various countries. With the continuous introduction of new technologies, new products, and new management measures, the problem of antimicrobial resistance must be controlled and alleviated.
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OBJECTIVE To survey the distribution of class Ⅰ integron in extended-spectrum beta-lactamases(ESBLs)-producing Escherichia coli and Klebsiella pneumoniae and its contribution in horizontal transfer of ESBLs genes.METHODS The presence of class Ⅰ integron among 230 ESBLs-producers and 197 non-ESBLs-producers of E.coli and K.pneumoniae were detected by PCR.The correlation and co-transfer between integron and genes coding for SHV,CTX and TEM were studied. RESULTS One hundred and thirty-seven(59.6%) isolates were positive for intⅠ gene among ESBLs-producers,contrasted to 48(24.4%) in non-ESBLs-producers(P
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Isolate, purify, and identify bacteria from probiotic supplement. Results: 5 strains of lactic bacteria were determined, including: Steptococus feacalis; Streptococcus lactic; Bifidobacterium bifidum; Lactobaccillus acidophilus; Lactobacillus casei. Study the sensitivity of these bacteria with antibiotics, results showed that these bacteria were resistant to many antibiotics, especially oral antibiotics. Conjugative trial between Streptoccocus feacalis, Streptococus lactic, Bifidobacterium bifidum, lactobacillus acidophilus casei and E.coli K12, and conjugative trial of lactic bacteria together showed negative results. Therefore, probiotic product contained many lactic bacteria can be used concomitant with some oral antibiotics to prevent or treat digestive disorders
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Anti-Bacterial Agents , BacteriaABSTRACT
Objective To develop a multiplex PCR-based reverse line blot(mPCR/RLB) hybridization assay to detect,simultaneously,seven genes encoding AR-erm(A/TR),erm(B),mef(A/ E),tet(M),tet(O),aphA-3,aad-6 and two AR-related genes,int-Tn and mreA in group B streptococcus.Methods Nine pairs of specific primers and Oligonucleotide probes targeting erm(A/TR), erm(B),mef(A/E),tet(M),tet(O),aphA-3,aad-6 int-Tn and mreA respectively were modified according to former studies or designed in this study.The primers and probes were labeled with biotin and amino,respectively.The nine genes were amplified simultaneously in the same tube.PCR product hybridized with the probes labeled in the BiodyneC nylon membrane to detect the nine genes.To detect the sensitivity and specificity of the method developed,PCR with single pair of primer targeting each gene were tested in 318 isolates tested and the results were compared with the one abtained by RLB.Results The nine resistance-related genes could be successfully detected by mPCR/RLB assay developed in this study.Based on sequencing,21 of 22 isolates with mef had mef(E)and eight of 353 with int-Tn had an atypical sequence.Except for the above 29 genes,all the others corresponded well with the results obtained by single pair primer PCR.Conclusion The mPCR/RLB assay developed in this study is simple,rapid and suitable for surveillance of antibiotic resistance in GBS.
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OBJECTIVE To investigate the staphylococcal cassette chromosome mec(SCCmec) genotype characteristics and antibiotic-resistant genes in meticillin-resistant Staphylococcus aureus(MRSA) isolated from Lianyungang.METHODS The SCCmec of clinically isolated MRSA strains were genotyped with a novel multiplex PCR strategy reported by Zhangetal.Antibiotic-resistant genes of aac(6′)/aph(2″),aph(3′)Ⅲ,tetM,erm,TEM,and ant(4′,4″) were analyzed by traditional PCR.RESULTS The isolates were almost SCCmec Ⅲ positve,only one isolate couldn′t be typed.The positive rates of aac(6′)/aph(2″),aph(3′)Ⅲ,tetM,and erm were 98%,46%,72% and 86%,respectively.TEM and ant(4′,4″) tested were all negative.CONCLUSIONS Almost all genotypes of MRSA prevailing in Lianyungang carry the SCCmec Ⅲ gene.There are high positive percentages of antibiotic-resistant genes of aac(6′)/aph(2″),aph(3′)Ⅲ,tetM and erm in the isolates.The novel multiplex PCR strategy recommended by Zhang et al can be applied into genotyping study of MRSA SCCmec effectively.
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Recombination plasmid pMM085 possessed both immunogens heat-labile enterotoxin(LT) and fimbriae antigen K88 of enterotoxigenic Escherichia coli (ETEC). Althouth vaccine strain MM-3 carrying pMM085 had good effect to protect piglets against diarrhea due to ETEC infections,it was not ideal live vaccine for pMM085 bringing chloramphenicol resistance gene (cat). To solve the problem,the host-plasmid balanced lethal system was introduced which including the replacement of cat gene by asd gene and transformation the new plasmid to the strain X6097 which asd gene was knocked out in its chromosome. Considering pMM085 was a big plasmid (23kb) and traditional genetic manipulations was not easy to carry on,?-Red recombination system was adopt in this work to realize the replacement of cat gene by asd gene. The results indicated that ?-Red recombination system was convenient and efficient to reconstruct big plasmid.