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Villarreal-Salazar V, Mendoza-Olazarán S, Flores-Treviño S, Garza-González E, Bocanegra-Ibarias P, Morfín-Otero R, Camacho-Ortiz A, Rodríguez-Noriega E, Villarreal-Treviño L. Rapid methicillin resistance detection and subspecies discrimination in Staphylococcus hominis clinical isolates by MALDI-TOF MS. Indian J Med Microbiol 2023; 41:83-89. [PMID: 36123270 DOI: 10.1016/j.ijmmb.2022.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 06/06/2022] [Accepted: 08/14/2022] [Indexed: 11/05/2022]
Abstract
PURPOSE Staphylococcus hominis is a coagulase-negative opportunistic pathogen responsible for implanted medical device infections. Rapid identification and virulence factors detection are crucial for appropriate antimicrobial therapy. We aimed to search protein biomarker peaks for rapid classification of antibiotic resistance and subspecies of S. hominis using MALDI-TOF MS. METHODS S. hominis clinical isolates (n = 148) were screened for subspecies differentiation by novobiocin resistance. Biofilm composition and formation were determined by detachment assay and crystal violet staining, respectively. Antibiotic susceptibility was performed by the broth microdilution method. The search for potential biomarkers peaks was enabled by ClinProTools 3.0, flexAnalysis 3.4, and Biotools 3.2 for statistical analysis, peak visualization, and protein/peptide alignment, respectively. RESULTS Of 148 isolates, 12.16% were classified as S. hominis subsp. novobiosepticus, 77.77% were biofilm producers, and ˃ 50% were multidrug-resistant. Two potential biomarker peaks, 8975 m/z and 9035 m/z were detected for the discrimination of methicillin resistance with a sensitivity of 96.72%. The following peaks were detected for subspecies differentiation: 2582 m/z, 2823 m/z, and 2619 m/z with 88.89-98.28% of sensitivity. CONCLUSIONS We found potential biomarker peaks to predict methicillin resistance and discriminate S. hominis subspecies during routine MALDI-TOF MS identification in a clinical setting to enable better antibiotic treatment.
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Affiliation(s)
- Verónica Villarreal-Salazar
- Laboratorio de Microbiología General, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Av. Pedro de Alba S/N, Col. Ciudad Universitaria, 66450, San Nicolás de los Garza, Nuevo León, México
| | - Soraya Mendoza-Olazarán
- Servicio de Gastroenterología, Hospital Universitario "Dr. José E. González" y Facultad de Medicina, Universidad Autónoma de Nuevo León, Av. Francisco I, Madero Pte. S/N Monterrey y Av. Gonzalitos, Col. Mitras Centro, 64460, Monterrey, Nuevo León, México
| | - Samantha Flores-Treviño
- Servicio de Infectología, Hospital Universitario "Dr. José E. González", Universidad Autónoma de Nuevo León, Av. Francisco I, Madero Pte. S/N Monterrey y Av. Gonzalitos, Col. Mitras Centro, 64460, Monterrey, Nuevo León, México
| | - Elvira Garza-González
- Servicio de Infectología, Hospital Universitario "Dr. José E. González", Universidad Autónoma de Nuevo León, Av. Francisco I, Madero Pte. S/N Monterrey y Av. Gonzalitos, Col. Mitras Centro, 64460, Monterrey, Nuevo León, México
| | - Paola Bocanegra-Ibarias
- Servicio de Infectología, Hospital Universitario "Dr. José E. González", Universidad Autónoma de Nuevo León, Av. Francisco I, Madero Pte. S/N Monterrey y Av. Gonzalitos, Col. Mitras Centro, 64460, Monterrey, Nuevo León, México
| | - Rayo Morfín-Otero
- Hospital Civil de Guadalajara "Fray Antonio Alcalde" y el Instituto de Patólogía Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Jalisco, México
| | - Adrián Camacho-Ortiz
- Servicio de Infectología, Hospital Universitario "Dr. José E. González", Universidad Autónoma de Nuevo León, Av. Francisco I, Madero Pte. S/N Monterrey y Av. Gonzalitos, Col. Mitras Centro, 64460, Monterrey, Nuevo León, México
| | - Eduardo Rodríguez-Noriega
- Hospital Civil de Guadalajara "Fray Antonio Alcalde" y el Instituto de Patólogía Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Jalisco, México
| | - Licet Villarreal-Treviño
- Laboratorio de Microbiología General, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Av. Pedro de Alba S/N, Col. Ciudad Universitaria, 66450, San Nicolás de los Garza, Nuevo León, México.
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Gostev V, Leyn S, Kruglov A, Likholetova D, Kalinogorskaya O, Baykina M, Dmitrieva N, Grigorievskaya Z, Priputnevich T, Lyubasovskaya L, Gordeev A, Sidorenko S. Global Expansion of Linezolid-Resistant Coagulase-Negative Staphylococci. Front Microbiol 2021; 12:661798. [PMID: 34589061 PMCID: PMC8473885 DOI: 10.3389/fmicb.2021.661798] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 07/30/2021] [Indexed: 11/13/2022] Open
Abstract
Coagulase-negative staphylococci (CoNS) for a long time were considered avirulent constituents of the human and warm-blooded animal microbiota. However, at present, S. epidermidis, S. haemolyticus, and S. hominis are recognized as opportunistic pathogens. Although linezolid is not registered for the treatment of CoNS infections, it is widely used off-label, promoting emergence of resistance. Bioinformatic analysis based on maximum-likelihood phylogeny and Bayesian clustering of the CoNS genomes obtained in the current study and downloaded from public databases revealed the existence of international linezolid-resistant lineages, each of which probably had a common predecessor. Linezolid-resistant S. epidermidis sequence-type (ST) 2 from Russia, France, and Germany formed a compact group of closely related genomes with a median pairwise single nucleotide polymorphism (SNP) difference of fewer than 53 SNPs, and a common ancestor of this lineage appeared in 1998 (1986-2006) before introduction of linezolid in practice. Another compact group of linezolid-resistant S. epidermidis was represented by ST22 isolates from France and Russia with a median pairwise SNP difference of 40; a common ancestor of this lineage appeared in 2011 (2008-2013). Linezolid-resistant S. hominis ST2 from Russia, Germany, and Brazil also formed a group with a high-level genome identity with median 25.5 core-SNP differences; the appearance of the common progenitor dates to 2003 (1996-2012). Linezolid-resistant S. hominis isolates from Russia demonstrated associated resistance to teicoplanin. Analysis of a midpoint-rooted phylogenetic tree of the group confirmed the genetic proximity of Russian and German isolates; Brazilian isolates were phylogenetically distant. repUS5-like plasmids harboring cfr were detected in S. hominis and S. haemolyticus.
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Affiliation(s)
- Vladimir Gostev
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia.,Department of Medical Microbiology, North-Western State Medical University Named After I. I. Mechnikov, Saint Petersburg, Russia
| | - Semen Leyn
- Infectious and Inflammatory Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Alexander Kruglov
- Laboratory of Clinical Microbiology, National Agency for Clinical Pharmacology and Pharmacy, Moscow, Russia
| | - Daria Likholetova
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia.,Saint Petersburg State University, Saint Petersburg, Russia
| | - Olga Kalinogorskaya
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
| | - Marina Baykina
- Laboratory of Clinical Microbiology, National Agency for Clinical Pharmacology and Pharmacy, Moscow, Russia
| | - Natalia Dmitrieva
- Department of Microbiology, N. N. Blokhin Russian Cancer Research Center, Moscow, Russia
| | - Zlata Grigorievskaya
- Department of Microbiology, N. N. Blokhin Russian Cancer Research Center, Moscow, Russia
| | - Tatiana Priputnevich
- Department of Microbiology, Clinical Pharmacology and Epidemiology, National Medical Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia
| | - Lyudmila Lyubasovskaya
- Department of Microbiology, Clinical Pharmacology and Epidemiology, National Medical Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia
| | - Alexey Gordeev
- Department of Microbiology, Clinical Pharmacology and Epidemiology, National Medical Research Center for Obstetrics, Gynecology and Perinatology, Moscow, Russia
| | - Sergey Sidorenko
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia.,Department of Medical Microbiology, North-Western State Medical University Named After I. I. Mechnikov, Saint Petersburg, Russia
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Mobile Oxazolidinone Resistance Genes in Gram-Positive and Gram-Negative Bacteria. Clin Microbiol Rev 2021; 34:e0018820. [PMID: 34076490 DOI: 10.1128/cmr.00188-20] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Seven mobile oxazolidinone resistance genes, including cfr, cfr(B), cfr(C), cfr(D), cfr(E), optrA, and poxtA, have been identified to date. The cfr genes code for 23S rRNA methylases, which confer a multiresistance phenotype that includes resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins, and streptogramin A compounds. The optrA and poxtA genes code for ABC-F proteins that protect the bacterial ribosomes from the inhibitory effects of oxazolidinones. The optrA gene confers resistance to oxazolidinones and phenicols, while the poxtA gene confers elevated MICs or resistance to oxazolidinones, phenicols, and tetracycline. These oxazolidinone resistance genes are most frequently found on plasmids, but they are also located on transposons, integrative and conjugative elements (ICEs), genomic islands, and prophages. In these mobile genetic elements (MGEs), insertion sequences (IS) most often flanked the cfr, optrA, and poxtA genes and were able to generate translocatable units (TUs) that comprise the oxazolidinone resistance genes and occasionally also other genes. MGEs and TUs play an important role in the dissemination of oxazolidinone resistance genes across strain, species, and genus boundaries. Most frequently, these MGEs also harbor genes that mediate resistance not only to antimicrobial agents of other classes, but also to metals and biocides. Direct selection pressure by the use of antimicrobial agents to which the oxazolidinone resistance genes confer resistance, but also indirect selection pressure by the use of antimicrobial agents, metals, or biocides (the respective resistance genes against which are colocated on cfr-, optrA-, or poxtA-carrying MGEs) may play a role in the coselection and persistence of oxazolidinone resistance genes.
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Al-Bdery ASJ, Mohammad GJ, Hussen B. Vancomycin and linezolid resistance among multidrug-resistant Staphylococcus aureus clinical isolates and interaction with neutrophils. GENE REPORTS 2020. [DOI: 10.1016/j.genrep.2020.100804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Mendoza-Olazarán S, Morfín-Otero R, Villarreal-Treviño L, Rodríguez-Noriega E, Llaca-Díaz J, Camacho-Ortiz A, González GM, Casillas-Vega N, Garza-González E. Antibiotic Susceptibility of Biofilm Cells and Molecular Characterisation of Staphylococcus hominis Isolates from Blood. PLoS One 2015; 10:e0144684. [PMID: 26659110 PMCID: PMC4685997 DOI: 10.1371/journal.pone.0144684] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 11/23/2015] [Indexed: 11/19/2022] Open
Abstract
Objectives We aimed to characterise the staphylococcal cassette chromosome mec (SCCmec) type, genetic relatedness, biofilm formation and composition, icaADBC genes detection, icaD expression, and antibiotic susceptibility of planktonic and biofilm cells of Staphylococcus hominis isolates from blood. Methods The study included 67 S. hominis blood isolates. Methicillin resistance was evaluated with the cefoxitin disk test. mecA gene and SCCmec were detected by multiplex PCR. Genetic relatedness was determined by pulsed-field gel electrophoresis. Biofilm formation and composition were evaluated by staining with crystal violet and by detachment assay, respectively; and the biofilm index (BI) was determined. Detection and expression of icaADBC genes were performed by multiplex PCR and real-time PCR, respectively. Antibiotic susceptibilities of planktonic cells (minimum inhibitory concentration, MIC) and biofilm cells (minimum biofilm eradication concentration, MBEC) were determined by the broth dilution method. Results Eighty-five percent (57/67) of isolates were methicillin resistant and mecA positive. Of the mecA-positive isolates, 66.7% (38/57) carried a new putative SCCmec type. Four clones were detected, with two to five isolates each. Among all isolates, 91% (61/67) were categorised as strong biofilm producers. Biofilm biomass composition was heterogeneous (polysaccharides, proteins and DNA). All isolates presented the icaD gene, and 6.66% (1/15) isolates expressed icaD. This isolate presented the five genes of ica operon. Higher BI and MBEC values than the MIC values were observed for amikacin, vancomycin, linezolid, oxacillin, ciprofloxacin, and chloramphenicol. Conclusions S. hominis isolates were highly resistant to methicillin and other antimicrobials. Most of the detected SCCmec types were different than those described for S. aureus. Isolates indicated low clonality. The results indicate that S. hominis is a strong biofilm producer with an extracellular matrix with similar composition of proteins, DNA and N-acetylglucosamine; and presents high frequency and low expression of icaD gene. Biofilm production is associated with increased antibiotic resistance.
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Affiliation(s)
- Soraya Mendoza-Olazarán
- Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
| | - Rayo Morfín-Otero
- Hospital Civil de Guadalajara, Fray Antonio Alcalde, and Instituto de Patología Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Licet Villarreal-Treviño
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Biológicas, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
| | - Eduardo Rodríguez-Noriega
- Hospital Civil de Guadalajara, Fray Antonio Alcalde, and Instituto de Patología Infecciosa y Experimental, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Jorge Llaca-Díaz
- Departamento de Patología Clínica, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
| | - Adrián Camacho-Ortiz
- Servicio de Infectología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
| | - Gloria M. González
- Departamento de Microbiología, Facultad de Medicina, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
| | - Néstor Casillas-Vega
- Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
| | - Elvira Garza-González
- Servicio de Gastroenterología, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
- Departamento de Patología Clínica, Hospital Universitario Dr. José Eleuterio González, Universidad Autónoma de Nuevo León, Monterrey, Nuevo León, México
- * E-mail:
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Cidral TA, Carvalho MC, Figueiredo AMS, de Melo MCN. Emergence of methicillin-resistant coagulase-negative staphylococci resistant to linezolid with rRNA gene C2190T and G2603T mutations. APMIS 2015; 123:867-71. [PMID: 26227107 DOI: 10.1111/apm.12426] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 06/21/2015] [Indexed: 12/01/2022]
Abstract
The aim of this article were to determinate the mechanism of linezolid resistance in coagulase-negative methicillin-resistant staphylococci from hospitals in the northeast of Brazil. We identified the isolates using VITEK(®) 2 and MALDI-TOF. Susceptibility to antibiotics was measured by the disk-diffusion method and by Etest(®) . Extraction of the whole genome DNA was performed, followed by screening of all the strains for the presence of mecA and cfr genes. The domain V region of 23S rRNA gene was sequenced and then aligned with a linezolid-susceptible reference strain. Pulsed-field gel electrophoresis (PFGE) macro-restriction analysis was performed. Three linezolid-resistant Staphylococcus hominis and two linezolid-resistant Staphylococcus epidermidis strains were analyzed. The isolates showed two point mutations in the V region of the 23S rRNA gene (C2190T and G2603T). We did not detect the cfr gene in any isolate by PCR. The S. hominis showed the same pulsotype, while the S. epidermidis did not present any genetic relation to each other. In conclusion, this study revealed three S. hominis and two S. epidermidis strains with resistance to linezolid due to a double mutation (C2190T and G2603T) in the domain V of the 23S rRNA gene. For the first time, the mutation of C2190T in S. epidermidis is described. This study also revealed the clonal spread of a S. hominis pulsotype between three public hospitals in the city of Natal, Brazil. These findings highlight the importance of continued vigilance of linezolid resistance in staphylococci.
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Affiliation(s)
- Thiago André Cidral
- Departamento de Microbiologia e Parasitologia, Laboratório de Bacteriologia Médica, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN
| | - Maria Cícera Carvalho
- Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Bloco i, Cidade Universitária, Ilha do fundão, Rio de Janeiro, RJ, Brazil
| | - Agnes Marie Sá Figueiredo
- Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Bloco i, Cidade Universitária, Ilha do fundão, Rio de Janeiro, RJ, Brazil
| | - Maria Celeste Nunes de Melo
- Departamento de Microbiologia e Parasitologia, Laboratório de Bacteriologia Médica, Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, RN
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Mutations in the bacterial ribosomal protein l3 and their association with antibiotic resistance. Antimicrob Agents Chemother 2015; 59:3518-28. [PMID: 25845869 DOI: 10.1128/aac.00179-15] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 03/31/2015] [Indexed: 11/20/2022] Open
Abstract
Different groups of antibiotics bind to the peptidyl transferase center (PTC) in the large subunit of the bacterial ribosome. Resistance to these groups of antibiotics has often been linked with mutations or methylations of the 23S rRNA. In recent years, there has been a rise in the number of studies where mutations have been found in the ribosomal protein L3 in bacterial strains resistant to PTC-targeting antibiotics but there is often no evidence that these mutations actually confer antibiotic resistance. In this study, a plasmid exchange system was used to replace plasmid-carried wild-type genes with mutated L3 genes in a chromosomal L3 deletion strain. In this way, the essential L3 gene is available for the bacteria while allowing replacement of the wild type with mutated L3 genes. This enables investigation of the effect of single mutations in Escherichia coli without a wild-type L3 background. Ten plasmid-carried mutated L3 genes were constructed, and their effect on growth and antibiotic susceptibility was investigated. Additionally, computational modeling of the impact of L3 mutations in E. coli was used to assess changes in 50S structure and antibiotic binding. All mutations are placed in the loops of L3 near the PTC. Growth data show that 9 of the 10 mutations were well accepted in E. coli, although some of them came with a fitness cost. Only one of the mutants exhibited reduced susceptibility to linezolid, while five exhibited reduced susceptibility to tiamulin.
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Linezolid-resistant Staphylococcus haemolyticus and Staphylococcus hominis: single and double mutations at the domain V of 23S rRNA among isolates from a Rio de Janeiro hospital. Diagn Microbiol Infect Dis 2014; 80:307-10. [PMID: 25294302 DOI: 10.1016/j.diagmicrobio.2014.09.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 08/19/2014] [Accepted: 09/12/2014] [Indexed: 11/21/2022]
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Tian Y, Li T, Zhu Y, Wang B, Zou X, Li M. Mechanisms of linezolid resistance in staphylococci and enterococci isolated from two teaching hospitals in Shanghai, China. BMC Microbiol 2014; 14:292. [PMID: 25420718 PMCID: PMC4245736 DOI: 10.1186/s12866-014-0292-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Accepted: 11/11/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Linezolid is one of the most effective treatments against Gram-positive pathogens. However, linezolid-resistant/intermediate strains have recently emerged in worldwide. The purpose of this study was to analyse the prevalence and resistance mechanisms of linezolid-resistant/intermediate staphylococci and enterococci in Shanghai, China. RESULTS Thirty-two linezolid-resistant/intermediate strains, including 14 Staphylococcus capitis, three Staphylococcus aureus, 14 Enterococcus faecalis and one Enterococcus faecium clinical isolates, were collected in this study which displayed linezolid MICs of 8 to 512 μg/ml, 8-32 μg/ml, 4-8 μg/ml and 4 μg/ml, respectively. All linezolid-resistant S. capitis isolates had a novel C2131T mutation and a G2603T mutation in the 23S rRNA region, and some had a C316T (Arg106Cys) substitution in protein L4 and/or harboured cfr. Linezolid-resistant S. aureus isolates carried a C389G (Ala130Gly) substitution in protein L3, and/or harboured cfr. The cfr gene was flanked by two copies of the IS256-like element, with a downstream orf1 gene. Linezolid-resistant/intermediate enterococci lacked major resistance mechanisms. The semi-quantitative biofilm assay showed that 14 linezolid-resistant E. faecalis isolates produced a larger biofilm than linezolid-susceptible E. faecalis strains. Transmission electron microscopy showed the cell walls of linezolid-resistant/intermediate strains were thicker than linezolid-susceptible strains. CONCLUSION Our data indicated that major resistance mechanisms, such as mutations in 23S rRNA and ribosomal proteins L3 and L4, along with cfr acquisition, played an important role in linezolid resistance. Secondary resistance mechanisms, such as biofilm formation and cell wall thickness, should also be taken into account.
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Affiliation(s)
| | | | | | | | | | - Min Li
- Department of Laboratory Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
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Takaya A, Kimura A, Sato Y, Ishiwada N, Watanabe M, Matsui M, Shibayama K, Yamamoto T. Molecular characterization of linezolid-resistant CoNS isolates in Japan. J Antimicrob Chemother 2014; 70:658-63. [PMID: 25381168 DOI: 10.1093/jac/dku443] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVES Linezolid has been reported to remain active against 98% of staphylococci with resistance identified in 0.05% of Staphylococcus aureus and 1.4% of CoNS. The objective of this study was to characterize the linezolid-resistance mechanisms in the linezolid-resistant CoNS strains isolated in Japan. METHODS Staphylococcus capitis strains exhibiting linezolid MICs >8 mg/L isolated from inpatients between 2012 and 2014 were screened for cfr and mutations in 23S rRNA, L3 and L4 by PCR/sequencing. Isolates were also examined for mutations in the rlmN gene. RESULTS S. capitis had six 23S rRNA alleles. Five S. capitis isolates displayed linezolid MICs of 8, 16 and 32 mg/L. G2576U mutations were detected in three, four or five copies of 23S rRNA in all isolates. In two isolates exhibiting the highest linezolid MIC (32 mg/L) there was a large deletion in a single copy of 23S rRNA. Repeated 10 bp sequences were found in both 16S and 23S rRNAs, suggesting deletion by recombination between the repeats. One isolate had the mutation Ala-142→Thr in the ribosomal protein L3. All linezolid-resistant isolates also demonstrated mutations in the gene encoding RlmN methyltransferase, leading to Thr-62→Met and Gly-148→Ser. CONCLUSIONS Multiple mechanisms appeared to be responsible for the elevated linezolid resistance in S. capitis isolates: a G2576U mutation in different numbers of copies of 23S rRNA, loss of a single copy of 23S rRNA and a mutation in the ribosomal protein L3, suggesting the accumulation of independent mutational events.
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Affiliation(s)
- Akiko Takaya
- Department of Microbiology and Molecular Genetics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Asahi Kimura
- Department of Microbiology and Molecular Genetics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Yoshiharu Sato
- Department of Microbiology and Molecular Genetics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Naruhiko Ishiwada
- Division of Control and Treatment of Infectious Diseases, Chiba University Hospital, Chiba 260-8677, Japan
| | - Masaharu Watanabe
- Division of Laboratory Medicine, Chiba University Hospital, Chiba 260-8677, Japan
| | - Mari Matsui
- Department of Bacteriology II, National Institute of Infectious Diseases, Musashimurayama, Tokyo 208-0011, Japan
| | - Keigo Shibayama
- Department of Bacteriology II, National Institute of Infectious Diseases, Musashimurayama, Tokyo 208-0011, Japan
| | - Tomoko Yamamoto
- Department of Microbiology and Molecular Genetics, Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
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Mendes RE, Deshpande LM, Jones RN. Linezolid update: stable in vitro activity following more than a decade of clinical use and summary of associated resistance mechanisms. Drug Resist Updat 2014; 17:1-12. [PMID: 24880801 DOI: 10.1016/j.drup.2014.04.002] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Linezolid, approved for clinical use since 2000, has become an important addition to the anti-Gram-positive infection armamentarium. This oxazolidinone drug has in vitro and in vivo activity against essentially all Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The in vitro activity of linezolid was well documented prior to its clinical application, and several ongoing surveillance studies demonstrated consistent and potent results during the subsequent years of clinical use. Emergence of resistance has been limited and associated with invasive procedures, deep organ involvement, presence of foreign material and mainly prolonged therapy. Non-susceptible organisms usually demonstrate alterations in the 23S rRNA target, which remain the main resistance mechanism observed in enterococci; although a few reports have described the detection of cfr-mediated resistance in Enterococcus faecalis. S. aureus isolates non-susceptible to linezolid remain rare in large surveillance studies. Most isolates harbour 23S rRNA mutations; however, cfr-carrying MRSA isolates have been observed in the United States and elsewhere. It is still uncertain whether the occurrences of such isolates are becoming more prevalent. Coagulase-negative isolates (CoNS) resistant to linezolid were uncommon following clinical approval. Surveillance data have indicated that CoNS isolates, mainly Staphylococcus epidermidis, currently account for the majority of Gram-positive organisms displaying elevated MIC results to linezolid. In addition, these isolates frequently demonstrate complex and numerous resistance mechanisms, such as alterations in the ribosomal proteins L3 and/or L4 and/or presence of cfr and/or modifications in 23S rRNA. The knowledge acquired during the past decades on this initially used oxazolidinone has been utilized for developing new candidate agents, such as tedizolid and radezolid, and as linezolid patents soon begin to expire, generic brands will certainly become available. These events will likely establish a new chapter for this successful class of antimicrobial agents.
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Affiliation(s)
| | | | - Ronald N Jones
- JMI Laboratories, North Liberty, IA 52317, USA; Tufts University School of Medicine, Boston, MA 02111, USA
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Linezolid resistance in vancomycin-resistant Enterococcus faecalis and Enterococcus faecium isolates in a Brazilian hospital. Antimicrob Agents Chemother 2014; 58:2993-4. [PMID: 24614366 DOI: 10.1128/aac.02399-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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