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Ratkai C, Quinteira S, Grosso F, Monteiro N, Nagy E, Peixe L. Controlling for false positives: interpreting MBL Etest and MBL combined disc test for the detection of metallo- -lactamases. J Antimicrob Chemother 2009; 64:657-8. [DOI: 10.1093/jac/dkp229] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Freitas AR, Novais C, Ruiz-Garbajosa P, Coque TM, Peixe L. Clonal expansion within clonal complex 2 and spread of vancomycin-resistant plasmids among different genetic lineages of Enterococcus faecalis from Portugal. J Antimicrob Chemother 2009; 63:1104-11. [PMID: 19329507 DOI: 10.1093/jac/dkp103] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The aim of this study was to assess the diversity of Enterococcus faecalis populations recovered in different regions of Portugal during the last decade (1996-2007) and to analyse their genetic elements associated with vancomycin resistance. METHODS Forty E. faecalis isolates (22 vancomycin-susceptible and 18 vancomycin-resistant) representing disseminated and/or multiresistant strains from different sources (humans, animals and the environment) were characterized by PFGE and multilocus sequence typing. Genes encoding putative virulence markers and the backbone of Tn1546 were investigated by PCR. Plasmid analysis included determination of size, content (S1 hybridization) and comparison of restriction fragment length polymorphism patterns. RESULTS The 40 E. faecalis isolates (22 PFGE types) mostly clustered within the worldwide-spread clonal complexes (CCs) CC2 (13 ST6 mostly corresponding to an epidemic strain, where ST stands for sequence type), CC21 (3 ST21, 1 ST22 and 1 ST224) and ST16 (n = 7), but also comprised ST159, ST35, ST19, ST26, ST30, ST41, ST55, ST59, ST117, ST160 and ST200. CC2 and CC21 were isolated from both hospital and community settings. Similar Tn1546-like elements encoding VanA were found on related plasmids within strains belonging to different clonal lineages and recovered in distinct hospitals over several years. CONCLUSIONS The predominance of E. faecalis CC2 is mainly due to the dissemination of a particular clone persistently recovered for 11 years. The presence in the community of specific strains belonging to major clonal lineages highlights the role of community-associated hosts as possible reservoirs of putative human pathogenic enterococci. Both clonal expansion and dissemination of epidemic conjugative VanA plasmids seem to join forces in the establishment of pathogenic E. faecalis strains.
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Machado E, Coque TM, Canton R, Sousa JC, Silva D, Ramos M, Rocha J, Ferreira H, Peixe L. Leakage into Portuguese aquatic environments of extended-spectrum- -lactamase-producing Enterobacteriaceae. J Antimicrob Chemother 2009; 63:616-8. [DOI: 10.1093/jac/dkn510] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Cantón R, Novais A, Valverde A, Machado E, Peixe L, Baquero F, Coque TM. Prevalence and spread of extended-spectrum beta-lactamase-producing Enterobacteriaceae in Europe. Clin Microbiol Infect 2008; 14 Suppl 1:144-53. [PMID: 18154538 DOI: 10.1111/j.1469-0691.2007.01850.x] [Citation(s) in RCA: 404] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Extended-spectrum beta-lactamases (ESBLs) represent a major threat among resistant bacterial isolates. The first types described were derivatives of the TEM-1, TEM-2 and SHV-1 enzymes during the 1980s in Europe, mainly in Klebsiella pneumoniae associated with nosocomial outbreaks. Nowadays, they are mostly found among Escherichia coli isolates in community-acquired infections, with an increasing occurrence of CTX-M enzymes. The prevalence of ESBLs in Europe is higher than in the USA but lower than in Asia and South America. However, important differences among European countries have been observed. Spread of mobile genetic elements, mainly epidemic plasmids, and the dispersion of specific clones have been responsible for the increase in ESBL-producing isolates, such as those with TEM-4, TEM-24, TEM-52, SHV-12, CTX-M-9, CTX-M-14, CTX-M-3, CTX-M-15 and CTX-M-32 enzymes.
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Coque TM, Novais A, Carattoli A, Poirel L, Pitout J, Peixe L, Baquero F, Cantón R, Nordmann P. Dissemination of clonally related Escherichia coli strains expressing extended-spectrum beta-lactamase CTX-M-15. Emerg Infect Dis 2008; 14:195-200. [PMID: 18258110 PMCID: PMC2600198 DOI: 10.3201/eid1402.070350] [Citation(s) in RCA: 568] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
E. coli ST131 and ST405 and multidrug-resistant IncFII plasmids may determine spread of this lactamase. We analyzed 43 CTX-M-15–producing Escherichia coli isolates and 6 plasmids encoding the blaCTX-M-15 gene from Canada, India, Kuwait, France, Switzerland, Portugal, and Spain. Most isolates belonged to phylogroups B2 (50%) and D (25%). An EC-B2 strain of clonal complex sequence type (ST) 131 was detected in all countries; other B2 isolates corresponded to ST28, ST405, ST354, and ST695 from specific areas. EC-D strains were clonally unrelated but isolates from 3 countries belonged to ST405. All CTX-M-15 plasmids corresponded to IncFII group with overrepresentation of 3 HpaI-digested plasmid DNA profiles (A, B and C; 85–120kb, similarity >70%). Plasmid A was detected in EC-B2 strains (ST131, ST354, or ST405), plasmid C was detected in B2 and D strains, and plasmid B was confined to worldwide-disseminated ST131. Most plasmids contained blaOXA-1, aac(6′)-Ib-cr, and blaTEM-1. Worldwide dissemination of CTX-M-15 seems to be determined by clonal complexes ST131 and ST405 and multidrug-resistant IncFII plasmids.
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Machado E, Coque TM, Cantón R, Sousa JC, Peixe L. Antibiotic resistance integrons and extended-spectrum -lactamases among Enterobacteriaceae isolates recovered from chickens and swine in Portugal. J Antimicrob Chemother 2008; 62:296-302. [PMID: 18456652 DOI: 10.1093/jac/dkn179] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Machado E, Coque TM, Cantón R, Novais A, Sousa JC, Baquero F, Peixe L. High diversity of extended-spectrum beta-lactamases among clinical isolates of Enterobacteriaceae from Portugal. J Antimicrob Chemother 2007; 60:1370-4. [PMID: 17913717 DOI: 10.1093/jac/dkm381] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To investigate the occurrence and the diversity of Ambler class A ESBLs among Enterobacteriaceae from different Portuguese clinical settings over a 2 year period (2002-04). METHODS One hundred and nine extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae isolates from five geographically distant health institutions in Portugal were studied. ESBLs were characterized by isoelectric focussing, PCR and further sequencing. Antibiotic susceptibility testing, transfer of resistance genes and clonal diversity were determined by standard procedures. Plasmid relatedness was established by comparison of random amplified polymorphic DNA (RAPD) patterns. RESULTS ESBLs were identified as TEM (46%), SHV (30%), CTX-M (22%) and GES (2%) types; TEM-24, TEM-52, SHV-12 and CTX-M-15 enzymes being the most frequently found. Inter-hospital dissemination of epidemic strains harbouring the most prevalent ESBLs was detected, including the TEM-24-producing Enterobacter aerogenes European epidemic clone. Conjugative transfer of ESBLs was achieved for 67% of isolates and epidemic plasmids containing specific bla genes were detected (bla(CTX-M-15) and bla(TEM-24)). We describe two new ESBLs, SHV-90 (A187T, G238S and E240K) and SHV-91 (P20S and E240K), and a new TEM-type enzyme conferring a phenotype resembling that of a complex mutant TEM beta-lactamase, designated as TEM-154 (M69L and R164S). The broad-spectrum beta-lactamases SHV-26, SHV-36 and TEM-110 were first observed in our country. CONCLUSIONS We describe a complex ESBL epidemiology in Portugal, including widespread dissemination of known strains and plasmids coding for TEM-24 and CTX-M-15 enzymes as observed in other European countries.
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Quinteira S, Grosso F, Ramos H, Peixe L. Molecular epidemiology of imipenem-resistant Acinetobacter haemolyticus and Acinetobacter baumannii isolates carrying plasmid-mediated OXA-40 from a Portuguese hospital. Antimicrob Agents Chemother 2007; 51:3465-6. [PMID: 17606684 PMCID: PMC2043188 DOI: 10.1128/aac.00267-07] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Machado E, Ferreira J, Novais A, Peixe L, Cantón R, Baquero F, Coque TM. Preservation of integron types among Enterobacteriaceae producing extended-spectrum beta-lactamases in a Spanish hospital over a 15-year period (1988 to 2003). Antimicrob Agents Chemother 2007; 51:2201-4. [PMID: 17404002 PMCID: PMC1891394 DOI: 10.1128/aac.01389-06] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The variable presence of integrons among extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae species (0 to 66%) is described. Association between bla(ESBL) and integrons occurred when these are linked to specific ESBL-type genes (In60 bearing ISCR1 and bla(CTX-M-9)) or when ESBL genes were superimposed onto selected plasmids carrying integrons. Some integrons were identical to those found during decades worldwide, illustrating the preservation of the genetic elements carrying them.
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Novais A, Cantón R, Machado E, Peixe L, Baquero F, Coque T. P1034 International dissemination of extended-spectrum β-lactamase TEM-24 among Enterobacteriaceae species is caused by spread of both epidemic IncA/C2 plasmid and strains. Int J Antimicrob Agents 2007. [DOI: 10.1016/s0924-8579(07)70875-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Freitas A, Novais C, Coque T, Peixe L. P688 Interhospital dissemination of glycopeptide resistance among enterococcal clinical isolates from Portugal is associated to spread of epidemic pMG1-like plasmids carrying diverse Tn1546 variants. Int J Antimicrob Agents 2007. [DOI: 10.1016/s0924-8579(07)70529-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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137
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Novais C, Freitas A, Coque T, Sousa J, Peixe L. O24 Multi-drug resistant enterococci among Portuguese swine after growth promoter ban. Int J Antimicrob Agents 2007. [DOI: 10.1016/s0924-8579(07)70023-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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138
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Antunes P, Machado J, Peixe L. Dissemination of sul3-containing elements linked to class 1 integrons with an unusual 3' conserved sequence region among Salmonella isolates. Antimicrob Agents Chemother 2007; 51:1545-8. [PMID: 17283193 PMCID: PMC1855504 DOI: 10.1128/aac.01275-06] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A sul3 domain (IS440-sul3-orf1-IS26) was found linked to an unusual 3' conserved sequence region (qacH) of class 1 integrons and detected among nontyphoid Salmonella isolates (n=47) from different sources. Three types of integrons differing in the gene cassette array (dfrA12-orfF-aadA2-cmlA1-aadA1, dfrA12-orfF-aadA2/1, and estX-psp-aadA2-cmlA1-aadA1) were found associated with this sul3 domain. They were associated with particular clones and specific high-molecular-weight plasmids.
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Antunes P, Machado J, Peixe L. Illegal use of nitrofurans in food animals: Contribution to human salmonellosis? Clin Microbiol Infect 2006; 12:1047-9. [PMID: 17002603 DOI: 10.1111/j.1469-0691.2006.01539.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Recent observations in Portugal of a remarkable incidence (65%) of Salmonella isolates from several sources (predominantly human and poultry) with decreased susceptibility to nitrofurantoin (MIC > or =64 mg/L), mostly comprising serogroup D isolates of Salmonella Enteritidis belonging to different phage types, suggest that illegal use of nitrofurans, especially in the poultry industry, might have contributed to the selection and prevalence of S. Enteritidis in food animals, and consequently to human salmonellosis in Portugal. Indiscriminate use of nitrofurans might also be implicated in the emergence of two multiresistant Salmonella Typhimurium clones disseminated throughout the country.
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Novais A, Cantón R, Moreira R, Peixe L, Baquero F, Coque TM. Emergence and dissemination of Enterobacteriaceae isolates producing CTX-M-1-like enzymes in Spain are associated with IncFII (CTX-M-15) and broad-host-range (CTX-M-1, -3, and -32) plasmids. Antimicrob Agents Chemother 2006; 51:796-9. [PMID: 17145793 PMCID: PMC1797763 DOI: 10.1128/aac.01070-06] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The spread of CTX-M-1-like enzymes in Spain is associated with particular plasmids of broad-host-range IncN (blaCTX-M-32, blaCTX-M-1), IncL/M (blaCTX-M-1), and IncA/C2 (blaCTX-M-3) or narrow-host-range IncFII (blaCTX-M-15). The identical genetic surroundings of blaCTX-M-32 and blaCTX-M-1 and their locations on related 40-kb IncN plasmids indicate the in vivo evolution of this element.
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141
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Machado E, Coque TM, Cantón R, Baquero F, Sousa JC, Peixe L. Dissemination in Portugal of CTX-M-15-, OXA-1-, and TEM-1-producing Enterobacteriaceae strains containing the aac(6')-Ib-cr gene, which encodes an aminoglycoside- and fluoroquinolone-modifying enzyme. Antimicrob Agents Chemother 2006; 50:3220-1. [PMID: 16940136 PMCID: PMC1563523 DOI: 10.1128/aac.00473-06] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Novais A, Cantón R, Valverde A, Machado E, Galán JC, Peixe L, Carattoli A, Baquero F, Coque TM. Dissemination and persistence of blaCTX-M-9 are linked to class 1 integrons containing CR1 associated with defective transposon derivatives from Tn402 located in early antibiotic resistance plasmids of IncHI2, IncP1-alpha, and IncFI groups. Antimicrob Agents Chemother 2006; 50:2741-50. [PMID: 16870767 PMCID: PMC1538643 DOI: 10.1128/aac.00274-06] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study analyzes the diversity of In60, a class 1 integron bearing CR1 and containing bla(CTX-M-9), and its association with Tn402, Tn21, and classical conjugative plasmids among 45 CTX-M-9-producing clinical strains (41 Escherichia coli strains, 2 Klebsiella pneumoniae strains, 1 Salmonella enterica strain, and 1 Enterobacter cloacae strain). Forty-five patients in a Spanish tertiary care hospital were studied (1996 to 2003). The diversity of In60 and association of In60 with Tn402 or mercury resistance transposons were investigated by overlapping PCR assays and/or hybridization. Plasmid characterization included comparison of restriction fragment length polymorphism patterns and determination of incompatibility group by PCR-based replicon typing, sequencing, and hybridization. CTX-M-9 plasmids belonged to IncHI2 (n = 26), IncP-1alpha (n = 10), IncFI (n = 4), and IncI (n = 1) groups. Genetic platforms containing bla(CTX-M-9) were classified in six types in relation to the In60 backbone and in eight subtypes in relation to Tn402 derivatives. They were associated with Tn21 sequences when located in IncP-1alpha or IncHI2 plasmids. Our study identified bla(CTX-M-9) in a high diversity of CR1-bearing class 1 integrons linked to different Tn402 derivatives, often to Tn21, highlighting the role of recombination events in the evolution of antibiotic resistance plasmids. The presence of bla(CTX-M-9) on broad-host-range IncP-1alpha plasmids might contribute to its dissemination to hosts that were not members of the family Enterobacteriaceae.
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Quinteira S, Peixe L. Multiniche screening reveals the clinically relevant metallo-beta-lactamase VIM-2 in Pseudomonas aeruginosa far from the hospital setting: an ongoing dispersion process? Appl Environ Microbiol 2006; 72:3743-5. [PMID: 16672526 PMCID: PMC1472372 DOI: 10.1128/aem.72.5.3743-3745.2006] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A screening study of the presence of metallo-beta-lactamases (IMP and VIM types and SPM-1) in isolates from different nonhospital sources was conducted, and it revealed the presence of bla(VIM-2), associated with the In58 class 1 integron, in two unrelated Pseudomonas aeruginosa strains from aquatic habitats. The results suggest that the hospital setting was the possible origin of these bla(VIM-2)-carrying strains.
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Antunes P, Machado J, Peixe L. Characterization of antimicrobial resistance and class 1 and 2 integrons in Salmonella enterica isolates from different sources in Portugal. J Antimicrob Chemother 2006; 58:297-304. [PMID: 16782741 DOI: 10.1093/jac/dkl242] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The antimicrobial resistance profiles of 1183 Salmonella isolates collected during 2002-2003 from several sources (human, food products and environment) were evaluated. The occurrence, distribution and cassette content of class 1 and 2 integrons among the sulphonamide-resistant population, as well as the role of particular clones to the spread of these genetic elements, were investigated. METHODS The isolates were examined for susceptibility to antimicrobial agents. The characterization of class 1 and 2 integrons was investigated using PCR, PCR-RFLP (restriction fragment length polymorphism) and sequencing in the sulphonamide-resistant isolates. Conjugation assays and clonality analysis by PFGE were performed. RESULTS The most common resistance phenotypes were to nalidixic acid, tetracycline, streptomycin, sulfamethoxazole and ampicillin (ranging from 31% to 17%). Resistance to sulphonamides (n=200) was associated with resistance to other antimicrobial agents, with 75% of the isolates carrying one or two class 1 integrons while only 3% simultaneously carried class 1 and 2 integrons. Integrons were observed among at least 11 serotypes (mainly Typhimurium) and in a reduced number of PFGE clones (20). Eight class 1 integron types were found, with the aadA genes (aadA1, aadA2 and aadA5) alone or downstream of a trimethoprim (dfrA1, dfrA12 and dfrA17) or a beta-lactamase resistance gene (blaoxa-30) and the blaPSE-1 gene alone. Most of the class 1 integron types were shared by several clones from the same or different serotypes obtained either from humans or food products of animal origin, especially pork products. However, some Typhimurium-specific integrons were found: aadA2 plus blaPSE-1 and blaoxa-30-aadA1. CONCLUSIONS Apart from the hypothetical contribution of the conjugative transfer of integrons, the incidence of Salmonella carrying these genetic units seems to rely on the ability of certain clones to spread or persist in particular animal niches. Our data suggest that food-producing animals might be simultaneously considered as a reservoir of clones and integrons carrying antibiotic resistance genes, thus making the food chain, especially pork products, a possible source of multidrug-resistant isolates in humans.
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Novais C, Coque TM, Boerlin P, Herrero I, Moreno MA, Dominguez L, Peixe L. Vancomycin-resistant Enterococcus faecium clone in swine, Europe. Emerg Infect Dis 2006; 11:1985-7. [PMID: 16485504 PMCID: PMC3367649 DOI: 10.3201/eid1112.050822] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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146
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Milhazes N, Calheiros R, Marques MPM, Garrido J, Cordeiro MNDS, Rodrigues C, Quinteira S, Novais C, Peixe L, Borges F. Beta-nitrostyrene derivatives as potential antibacterial agents: a structure-property-activity relationship study. Bioorg Med Chem 2006; 14:4078-88. [PMID: 16497504 DOI: 10.1016/j.bmc.2006.02.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 01/26/2006] [Accepted: 02/03/2006] [Indexed: 11/16/2022]
Abstract
A multidisciplinary project was developed, combining the synthesis of a series of beta-nitrostyrene derivatives and the determination of their physicochemical parameters (redox potentials, partition coefficients), to the evaluation of the corresponding antibacterial activity. A complete conformational analysis was also performed, in order to get relevant structural information. Subsequently, a structure-property-activity (SPAR) approach was applied, through linear regression analysis, aiming at obtaining a putative correlation between the physicochemical parameters of the compounds investigated and their antibacterial activity (both against standard strains and clinical isolates). The beta-nitrostyrene compounds displayed a lower activity towards all the tested bacteria relative to the beta-methyl-beta-nitrostyrene analogues. This was observed particularly for the 3-hydroxy-4-methoxy-beta-methyl-beta-nitrostyrene (IVb) against the Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium). The SPAR results revealed the existence of a clear correlation between the redox potentials and the antibacterial activity of the series of beta-nitrostyrene derivatives under study.
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147
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Quinteira S, Ferreira H, Peixe L. First isolation of blaVIM-2 in an environmental isolate of Pseudomonas pseudoalcaligenes. Antimicrob Agents Chemother 2005; 49:2140-1. [PMID: 15855549 PMCID: PMC1087648 DOI: 10.1128/aac.49.5.2140-2141.2005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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148
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Machado E, Cantón R, Baquero F, Galán JC, Rollán A, Peixe L, Coque TM. Integron content of extended-spectrum-beta-lactamase-producing Escherichia coli strains over 12 years in a single hospital in Madrid, Spain. Antimicrob Agents Chemother 2005; 49:1823-9. [PMID: 15855502 PMCID: PMC1087637 DOI: 10.1128/aac.49.5.1823-1829.2005] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The contribution of integrons to the dissemination of extended-spectrum beta-lactamases (ESBL) was analyzed on all ESBL-producing Escherichia coli isolates from 1988 to 2000 at Ramon y Cajal Hospital. We studied 133 E. coli pulsed-field gel electrophoresis types: (i) 52 ESBL-producing clinical strains (C-ESBL) (16 TEM, 9 SHV, 21 CTX-M-9, 1 CTX-M-14, and 5 CTX-M-10); (ii) 43 non-ESBL blood clinical strains (C-nESBL); and (iii) 38 non-ESBL fecal isolates from healthy volunteers (V-nESBL). Class 1 integrons were more common among C-ESBL (67%) than among C-nESBL (40%) or V-nESBL (26%) (P < 0.001) due to the high number of strains with bla(CTX-M-9), which is linked to an In6-like class 1 integron. Without this bias, class 1 integron occurrence would be similar in C-ESBL and C-nESBL groups (47% versus 40%). Occurrence of class 2 integrons was similar among clinical and community isolates (13 to 18%). No isolates contained class 3 integrons. The relatively low rate of class 1 integrons within transferable elements carrying bla(TEM) (23%) or bla(SHV) (33%) and the absence of class 2 integrons in all ESBL transconjugants mirror the assembly of translocative pieces containing bla(TEM) or bla(SHV) on local available transferable elements lacking integrons. The low diversity of class 1 integrons (seven types recovered in all groups) might indicate a wide dissemination of specific genetic elements in which they are located. In our environment, the spread of genetic elements encoding ESBL has no major impact on the dispersion of integrons, nor do integrons have a major impact on the spread of ESBL, except when bla(ESBL) genes are within an integron platform such as bla(CTX-M-9).
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Antunes P, Machado J, Sousa JC, Peixe L. Dissemination of sulfonamide resistance genes (sul1, sul2, and sul3) in Portuguese Salmonella enterica strains and relation with integrons. Antimicrob Agents Chemother 2005; 49:836-9. [PMID: 15673783 PMCID: PMC547296 DOI: 10.1128/aac.49.2.836-839.2005] [Citation(s) in RCA: 187] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In 200 sulfonamide-resistant Portuguese Salmonella isolates, 152 sul1, 74 sul2, and 14 sul3 genes were detected. Class 1 integrons were always associated with sul genes, including sul3 alone in some isolates. The sul3 gene has been identified in isolates from different sources and serotypes, which also carried a class 1 integron with aadA and dfrA gene cassettes.
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Quinteira S, Sousa JC, Peixe L. Characterization of In100, a new integron carrying a metallo-{beta}-lactamase and a carbenicillinase, from Pseudomonas aeruginosa. Antimicrob Agents Chemother 2005; 49:451-3. [PMID: 15616334 PMCID: PMC538865 DOI: 10.1128/aac.49.1.451-453.2005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In100, a new integron carrying a carbapenemase gene (bla(VIM-2)) associated with a carbenicillinase (blaP1b) and aminoglycoside resistance genes (aacA4 and aadA2), was detected in a Pseudomonas aeruginosa clinical isolate. The particular gene cassette organization of In100 seems to reflect the evolution of antibiotic usage in therapeutics.
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