Journal of Microbiology

Journal Articles

Molecular Characteristics and Resistant Mechanisms of Imipenem-Resistant Acinetobacter baumannii Isolates in Shenyang, China: Jing Ping Zhang , Wan Zhu , Su Fei Tian , Yun Zhuo Chu , Bai Yi Chen; J. Microbiol. 2010;48(5):689-694. Published online November 3, 2010; DOI: https://doi.org/10.1007/s12275-010-0137-3

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Abstract: The investigation was carried out to elucidate the molecular characteristics and resistant mechanisms of imipenem-resistant Acinetobacter baumannii. Thirty-seven isolates were collected from January 2007 to December 2007. The homology of the isolates was analyzed by both pulsed field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The genes of β-lactamases, adeB, and class 1 integron were polymerase chain reaction amplified. Genotype analysis of the 37 A. baumannii isolates by PFGE revealed the circulation of four PFGE types (A-D) ; the A- and B-type accounted for 48.6% and 40.5%, respectively. MLST showed the existence of three allelic profiles. The agar dilution method was carried out to determine the MIC of imipenem, in the absence or presence of carbonyl cyanide m-chlorophenylhydrazone (CCCP, 10 μg/ml). The MICs of the strains to imipenem were between 16 μg/ml and 128 μg/ml. When CCCP was added, a MIC decrease of at least four-fold was observed in 20 isolates, which belonged to the A- or C-type. AdeB and blaPER-1 genes were each detected in 35 isolates, blaOXA-23 gene in 34 isolates and blaOXA-58-like gene in 24 isolates. All isolates harbored blaOXA-51-like genes. No isolates carried the blaIMP-1 gene. Integron was detected in 25 isolates, which mediated the resistance to aminoglycosides and rifampin. The epidemiologic data suggested that the increasing infection of A. baumannii in our hospital was mainly caused by the inter-hospital spread of two epidemic clones. The AdeABC efflux system may be the important factor that leads to the high level of imipenem-resistance in PFGE A-type.

Antimicrobial Resistance Patterns and Characterization of Integrons of Shigella sonnei Isolates in Seoul, 1999-2008: Young-hee Jin , Young-hee Oh , Ji-hun Jung , Soo-jin Kim , Jin-ah Kim , Ki-young Han , Min-young Kim , Seog-gee Park , Young-ki Lee; J. Microbiol. 2010;48(2):236-242. Published online May 1, 2010; DOI: https://doi.org/10.1007/s12275-010-9220-z

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Abstract: A total of 66 Shigella sonnei isolates from 1999 to 2008 in Seoul was analyzed for their antimicrobial resistance, carriage of integron, and the patterns of Pulsed-field gel electrophoresis (PFGE). A high level of antimicrobial resistance to streptomycin (100%), trimethoprim/sulfamethoxazole (95%), tetracycline (94%), nalidixic acid (65%), and ampicillin (41%) was observed among S. sonnei isolates. Fourteen profiles of antimicrobial resistance were identified with the most common resistance profile being nalidixic acid, streptomycin, tetracycline, and trimethoprim/sulfamethoxazole (35%). PCR and DNA sequencing analysis revealed the presence of class 2 integron in all isolates, and class 1 and 2 integrons in 7 isolates. The class 2 integron carried two types of gene cassettes. One cassette array was dfrI, sat2, and aadA1 (91%), and the other was dfr1 and sat1 (8%). dfrA12 and aadA2 gene cassette was found in one isolate containing class 1 integron. PFGE was carried out to examine the genetic relatedness among isolates. All isolates except for one showed similar PFGE patterns (similarity of 80.1%). These results suggest that the S. sonnei isolated during 1999-2008 in Seoul have similar lineages that have not undergone evolutionary changes with time.

Research Support, Non-U.S. Gov'ts

Analysis of a Novel Class 1 Integron Containing Metallo-β-Lactamase Gene VIM-2 in Pseudomonas aeruginosa: Jae Hoon Jeong , Kyeong Seob Shin , Jang Won Lee , Eun Jin Park , Seung-Yeol Son; J. Microbiol. 2009;47(6):753-759. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-008-0272-2

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Abstract: Carbapenems such as imipenem are stable to most β-lactamases. Recently, increased numbers of carbapenemase producing Gram-negative bacterial strains have been isolated because of the increased use of cabapenems. In this respect, control of these infectious carbapenemase producing Gram-negative bacteria and understanding their resistance mechanism are becoming more important. These carbapenem-hydrolyzing β-lactamase genes have been reported to exist mostly as gene cassettes in an integron. This implies that antibiotic resistance genes may be transferred to other bacteria via the integron. In the present study, we identified and analyzed an integron containing VIM-2 type metallo-β-lactamase gene in a carbapenemase producing Pseudomonas aeruginosa. In addition, the possibility of resistance spread by integron located in a plasmid was tested. Among glucose non-fermenting Gram-negative bacilli with reduced imipenem susceptibility (MIC≥8 μg/ml) isolated from Korean patients, P. aeruginosa 1082 showed resistance to most β-lactams, cephalosporin, and aminoglycoside. We found that P. aeruginosa 1082 was inhibited by EDTA in EDTA double disk synergy test which means that this strain produces metallo-β-lactamase. Class 1 integron containing blaVIM-2 (carbapenem resistance gene), qacF (quaternary ammonium compound resistance gene), aacA4 (aminoglycoside resistance gene), catB3 (chloramphenicol resistance gene), blaOXA-30 (extended-spectrum β-lactam resistance gene), and aadA1 (aminoglycoside resistance gene) gene cassettes was detected in P. aeruginosa 1082. The size of the integron was 5,246 bp and the structure and arrangement of the integron was a novel one in comparison with other integrons found in other P. aeruginosa. The integron could be transferred to Escherichia coli JM109 from P. aeruginosa 1082 possibly via self-transferable plasmid DNA. The integron and a blaVIM-2 gene were detected in the plasmid DNA of the transconjugants whose imipenem resistance was slightly increased as a result of accepting the integron from the donor strain.

NOTE] Nomenclature of ISCR1 Elements Capable of Mobilizing Antibiotic Resistance Genes Present in Complex Class 1 Integrons: Seung Ghyu Sohn , Jae Jin Lee , Jae Seok Song , Jung Hun Lee , Ha Ik Sun , Kwang Seung Park , Il Kwon Bae , Jung-Hyun Lee , Byeong Chul Jeong , Sang Hee Lee; J. Microbiol. 2009;47(4):514-516. Published online September 9, 2009; DOI: https://doi.org/10.1007/s12275-009-0054-5

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Abstract: The dissemination of many antibiotic resistance genes has arisen among members of the family Enterobacteriaceae. The dissemination mechanism of these antibiotic resistance genes is closely linked with insertion sequence common region 1 (ISCR1). Thus, caution must be taken in clinical settings to prevent further dissemination of these antibiotic resistance genes. A nomenclature system of ISCR1 variants, important for the antibiotic resistance dissemination, was proposed. The proposed system can designate all ISCR1 variants on the basis of the detection time and by considering amino-acid substitution(s) compared with ISCR1a. This nomenclature system of ISCR1 variants can be applied to 19 groups (ISCR1 to ISCR19) of the ISCR family and help some researchers to correctly designate new ISCR subgroups.

Class 1 and Class 2 Integrons and Plasmid-Mediated Antibiotic Resistance in Coliforms Isolated from Ten Rivers in Northern Turkey: Osman Birol Ozgumus , Cemal Sandalli , Ali Sevim , Elif Celik-Sevim , Nuket Sivri; J. Microbiol. 2009;47(1):19-27. Published online February 20, 2009; DOI: https://doi.org/10.1007/s12275-008-0206-z

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Abstract: We aimed to determine the molecular mechanisms of antibiotic resistance in coliforms isolated from ten rivers in northern region of Turkey. A total of 183 isolates were tested for antimicrobial susceptibility by disk diffusion and agar dilution methods. Resistance to ampicillin, streptomycin, trimethoprim, tetracycline, and chloramphenicol was detected in 58%, 51.9%, 24%, 28.4%, and 12.5%, respectively. Twelve (6.5%) phylogenetically distant organisms were detected to harbor self-transmissible plasmids ranging 52 to >147 kb in sizes. Resistances to ampicillin, tetracycline, trimethoprim, streptomycin, and nalidixic acid were commonly transferable traits. Transferable nalidixic acid-resistant strains harbored qnrS gene, which was the first report of plasmid-mediated quinolone resistance in bacteria of environmental origin in Turkey. Fourteen and five coliforms harbored class 1 and class 2 integrons, respectively, and some of them were located on transferable plasmids. Sequence analyses of variable regions of the class 1 and 2 integrons harbored various gene cassettes, dfrA1, dfr2d, dfrA7, dfrA16, dfrA17, aadA1, aadA5, blaOXA-30, and sat1. A gene cassette array, dfrA16 has been demonstrated for the first time in a Citrobacter koseri isolate. Class 1 and class 2-bearing strains were clustered in different groups by BOX-PCR fingerprinting. Rivers in the northern Turkey may act as receptacle for the multi-drug resistant enterobacteria and can serve as reservoirs of the antimicrobial resistance determinants in the environment. The actual risk to public health is the transfer of resistance genes from the environmental bacteria to human pathogens.

Detection of Pseudomonas aeruginosa Carried a New Array of Gene Cassettes within Class 1 Integron Isolated from a Teaching Hospital in Nanjing, China: Yuan Wu† , Hui Li† , Jun Li , Zu Hu Huang; J. Microbiol. 2008;46(6):687-691. Published online December 24, 2008; DOI: https://doi.org/10.1007/s12275-008-0021-6

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Abstract: We report here novel array of gene cassettes found in single variable region of class 1 integron disseminated in Pseudomonas aeruginosa isolated from a teaching hospital in Nanjing, Jiangsu Province, China. 29 of 47 (61%) P. aeruginosa strains were confirmed haboured class 1 integron, and all the positive strains have the same variable region confirmed by PCR and RFLP methods. The variable region contained an unreported order of four gene cassettes aac(6’)-II-aadA13-cmlA8-oxa 10. Of those, cmlA8 gene was a variant of cmlA5 encoding non-enzymatic protein which putatively confer resistance to chloramphenicol. Susceptibility testing revealed multidrug-resistant mechanisms were involved in the class 1 integron positive clinical isolates. And the class 1 integron located on an about 15 kb transferable plasmid was certified by conjugation experiment and plasmid DNA analysis. The macro restriction profile indicated those clinical strains were clonally related.

Isolation of Multidrug-Resistant Salmonella typhimurium DT104 from Swine in Korea: Ki Eun Lee , Yeonhee Lee; J. Microbiol. 2007;45(6):590-592.; DOI: https://doi.org/2603 [pii]

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Abstract: We report the isolation of Salmonella enterica serotype Typhimurium phage type DT104 (CCARM 8104) from swine in Korea. The CCARM 8104 isolate was resistant to nalidixic acid and showed reduced susceptibility to quinolones. The CCARM 8104 isolate had a missense mutation, Asp87Asn, in the quinolone resistance-determining region in gyrA and produced PSE-1. The CCARM 8104 isolate carried two different class 1 integrons, and the PSE-1 β-lactamase gene was inserted into a 1,200 bp class 1 integron. The presence of DT104 with pse-1 in an integron located in a plasmid and reduced susceptibility to quinolone in swine pose a significant threat of possible horizontal spread between swine and humans.

Molecular Characterization of Antibiotic Resistant Escherichia coli Strains Isolated from Tap and Spring Waters in a Coastal Region in Turkey: Osman Birol Ozgumus , Elif Celik-Sevim , Sengul Alpay-Karaoglu , Cemal Sandalli , Ali Sevim; J. Microbiol. 2007;45(5):379-387.; DOI: https://doi.org/2600 [pii]

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Abstract: A hundred and seventeen antibiotic-resistant Escherichia coli strains were isolated from public tap and spring waters which were polluted by fecal coliforms. There were no significant differences between two water sources as to the coliform pollution level (p> 0.05). All E. coli isolates were detected to be resistant to one or more antibiotics tested. Nearly 42% of the isolates showed multiresistant phenotype. Three (2.5%) of these isolates contained class 1 integron. Sequencing analysis of variable regions of the class 1 integrons showed two gene cassette arrays, dfr1-aadA1 and dhfrA17-aadA5. Resistance to ampicillin, tetracycline or trimethoprim-sulfamethoxazole was transferable according to the results of conjugation experiments. The rate of tetracycline resistance was 15%. tet(A)-mediated tetracycline resistance was widespread among tetracycline-resistant E. coli isolates. Genotyping by BOX-polymerase chain reaction (BOX-PCR) showed that some of the strains were epidemiologically related. This is the first report on the prevalence and characterization of class 1 integron-containing E. coli isolates of environmental origin in Turkey.

Published Erratum

Erratum: Secretions from Serratia marcescens Inhibit the Growth and Biofilm Formation of Candida spp. and Cryptococcus neoformans: Caiyan Xin , Fen Wang , Jinping Zhang , Quan Zhou , Fangyan Liu , Chunling Zhao , Zhangyong Song; J. Microbiol. 2023;61(4):479-479.; DOI: https://doi.org/10.1007/s12275-023-00037-5

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Abstract

Erratum: Journal of Microbiology (2023) 61:221–232 https://doi.org/10.1007/s12275-022-00007-3 In this article the acknowledgment has been given erroneously. It should be read as follows: This research was supported financially by the Sichuan Science and Technology Program (2023NSFSC1698, 2023NSFSC0529, 2022NSFSC1539, and 2022YFS0629) and Luzhou (2021-JYJ-73 and 2022-JYJ-159), the Technology Strategic Cooperation Project of Luzhou Municipal People’s Government Southwest Medical University (2020LZXNYDJ38 and 2020LZXNYDJ23), and the Foundation of Southwest Medical University (2021ZKMS008, 2022QN042, 2022QN085, 2022QN102, and 2022QN118). The original article has been corrected.

Citations

Citations to this article as recorded by

Sensitive bioluminescence imaging of cryptococcosis in Galleria mellonella improves antifungal screening under in vivo conditions
Eliane Vanhoffelen, Lori Vermoesen, Lauren Michiels, Katrien Lagrou, Agustin Reséndiz-Sharpe, Greetje Vande Velde
Virulence.2024;[Epub] CrossRef

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