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Antibiotic Resistance Genes (antibiotic + resistance_gene)
Selected AbstractsAntibiotic resistance genes in multidrug-resistant Enterococcus spp. and Streptococcus spp. recovered from the indoor air of a large-scale swine-feeding operationLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2006A.R. Sapkota Abstract Aims:, In this study, multidrug-resistant bacteria previously recovered from the indoor air of a large-scale swine-feeding operation were tested for the presence of five macrolide, lincosamide and streptogramin (MLS) resistance genes and five tetracycline (tet) resistance genes. Methods and Results:,Enterococcus spp. (n = 16) and Streptococcus spp. (n =16) were analysed using DNA,DNA hybridization, polymerase chain reaction (PCR) and oligoprobing of PCR products. All isolates carried multiple MLS resistance genes, while 50% of the Enterococcus spp. and 44% of the Streptococcus spp. also carried multiple tet resistance genes. All Enterococcus spp. carried erm(A) and erm(B), 69% carried erm(F), 44% carried mef(A), 75% carried tet(M), 69% carried tet(L) and 19% carried tet(K). All Streptococcus spp. carried erm(B), 94% carried erm(F), 75% carried erm(A), 38% carried mef(A), 50% carried tet(M), 81% carried tet(L) and 13% carried tet(K). Conclusions:, Multidrug resistance among airborne bacteria recovered from a swine operation is encoded by multiple MLS and tet resistance genes. These are the first data regarding resistance gene carriage among airborne bacteria from swine-feeding operations. Significance and Impact of the Study:, The high prevalence of multiple resistance genes reported here suggests that airborne Gram-positive bacteria from swine operations may be important contributors to environmental reservoirs of resistance genes. [source] Characterization of integrons and antimicrobial resistance genes in clinical isolates of Gram-negative bacteria from Palestinian hospitalsMICROBIOLOGY AND IMMUNOLOGY, Issue 11 2009Amjad I. A. Hussein ABSTRACT Sixty Gram-negative bacterial isolates were collected from Palestinian hospitals in 2006. Thirty-two (53.3%) isolates showed multidrug resistance phenotypes. PCR and DNA sequencing were used to characterize integrons and antimicrobial resistance genes. PCR screening showed that 19 (31.7%) and five (8.3%) isolates were positive for class 1 and class 2 integrons, respectively. DNA-sequencing results for the captured antimicrobial resistance gene cassettes within class 1 integrons identified the following genes: dihydrofolate reductases, dfrA1, dfrA5, dfrA7, dfrA12, dfrA17 and dfrA25; aminoglycoside adenyltransferases, aadA1, aadA2, aadA5, aadA12 and aadB; aminoglycoside acetyltransferase, aac(6,)-Ib; and chloramphenicol resistance gene, cmlA1. ESBL were identified in 25 (41.7%) isolates. The identified ESBL were blaCTX-M-15, blaCTX-M-56, blaOXA-1, blaSHV-1, blaSHV-12, blaSHV-32 and blaTEM-1 genes. Moreover, we characterized the plasmid-mediated quinolone resistance genes, aac(6,)-Ib-cr and qnrB2, which were detected in seven (11.7%) and two (3.3%) isolates, respectively. In this study various types of antibiotic resistance genes have been identified in Gram-negative bacteria from Palestinian hospitals, many of which are reported in the Middle East area for the first time. [source] Using ColE1-derived RNA I for suppression of a bacterially encoded gene: implication for a novel plasmid addiction systemBIOTECHNOLOGY JOURNAL, Issue 6 2006Irene Pfaffenzeller Abstract The use of plasmid DNA for gene therapeutical purposes is a novel technology with advantages and drawbacks. One of the required improvements is to avoid antibiotic resistance genes or other additional sequences for selection within the plasmid. Here, we describe an alternative approach to equip a ColE1 plasmid with a regulatory function within the cell, which could be used for selection of plasmid carrying cells. No additional sequences are required, since the mechanism is based on RNA/RNA antisense interaction involving the naturally occurring RNA I derived from the plasmid's origin of replication. The plasmid replicational regulatory network was linked to the transcriptional regulatory network of an engineered target gene, present on the bacterial chromosome. Thus, gene suppression of a reporter could be achieved by mere presence of the ColE1-type plasmid pBR322. Proof of this concept was shown in shaker-flask experiments and fed-batch fermentation processes. The strategy of regulating gene expression by plasmid replication implicates a novel strategy for plasmid selection, as the gene to be suppressed could be toxic or growth hampering, providing advantage to plasmid carrying host cells. [source] Molecular epidemiology of clinically significant antibiotic resistance genesBRITISH JOURNAL OF PHARMACOLOGY, Issue S1 2008P M Hawkey Antimicrobials were first introduced into medical practice a little over 60 years ago and since that time resistant strains of bacteria have arisen in response to the selective pressure of their use. This review uses the paradigm of the evolution and spread of beta-lactamases and in particular beta-lactamases active against antimicrobials used to treat Gram-negative infections. The emergence and evolution particularly of CTX-M extended-spectrum beta-lactamases (ESBLs) is described together with the molecular mechanisms responsible for both primary mutation and horizontal gene transfer. Reference is also made to other significant antibiotic resistance genes, resistance mechanisms in Gram-negative bacteria, such as carbepenamases, and plasmid-mediated fluoroquinolone resistance. The pathogen Staphylococcus aureus is reviewed in detail as an example of a highly successful Gram-positive bacterial pathogen that has acquired and developed resistance to a wide range of antimicrobials. The role of selective pressures in the environment as well as the medical use of antimicrobials together with the interplay of various genetic mechanisms for horizontal gene transfer are considered in the concluding part of this review. British Journal of Pharmacology (2008) 153, S406,S413; doi:10.1038/sj.bjp.0707632 [source] Distribution of genotypes and antibiotic resistance genes among invasive Streptococcus agalactiae (group B streptococcus) isolates from Australasian patients belonging to different age groupsCLINICAL MICROBIOLOGY AND INFECTION, Issue 3 2008Z. Zhao Abstract Serotype distribution and antibiotic resistance (AR) among group B streptococci (GBS) affect GBS disease prevention strategies, but vary among patient groups. A multiplex PCR-based reverse line blot (mPCR/RLB) hybridisation assay was used to compare the distributions of GBS serotypes, serotype III subtypes and AR-associated genes among 666 invasive isolates from 663 patients, divided into five age groups: infants, early-onset (EO; 0,6 days) and late-onset (LO; 7,90 days); children (aged 3 months to 14 years); women of childbearing age (WCBA; aged 15,45 years); and other adults (males aged >15 years; females aged >45 years). Serotypes Ia and V and serosubtype III-1 accounted for 60% of infections. Serosubtype III-2, which corresponds to a virulent clone belonging to sequence type (ST)17, was relatively uncommon overall (7%), but was associated strongly with LO infant infections, in which it was significantly more common than in adult infections (25/104 (24%) vs. 9/392 (2%), p <0.0001) or in EO infections (25/104 (24%) vs. 14/155 (9%), p <0.005). Erythromycin resistance genes were found in 8% of all isolates (ermB 3%, ermA 2.5% and mefA/E 2%), in 11,15% of isolates of serotypes II and V and subtype III-1, but in none of the isolates of serosubtype III-2 (III-2, 0/49 vs. all others, 54/618 (9%), p <0.04). In summary, the virulent serosubtype III-2 was associated strongly with LO infant GBS infection, but was less likely than other serotypes or serosubtype III-1 to carry AR genes. [source] Molecular characterisation and clonal analysis of group A streptococci causing pharyngitis among paediatric patients in Palermo, ItalyCLINICAL MICROBIOLOGY AND INFECTION, Issue 2 2006G. Lorino Abstract Group A streptococci (n = 123), isolated consecutively from paediatric patients with pharyngitis from Palermo, Italy, were analysed. The emm and sof genes were sequenced, the presence of the speA and speC genes was investigated, and the macrolide resistance phenotypes and genotypes were determined. A limited number of emm/sof genotypes was found, and the most prevalent types were different from those found in a previous study from Rome. Macrolide resistance was found in the most prevalent clones, suggesting that the spread of mobile antibiotic resistance genes among the fittest clones in the community was the main mechanism influencing macrolide resistance rates in different emm types. [source] | |||||||||||||