Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
1.
Molecules ; 27(3)2022 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-35164360

RESUMEN

The essential oils were obtained by hydrodistillation from aerial parts of Mentha pulegium L. (M. pulegium L.) and Artemisia herba alba (A. herba alba) Asso. and analyzed by gas chromatography-flame ionization detector chromatograpy (GC-FID) and gaz chromatography-mass spectrometry (GC-MS). The antibacterial activities of the oils were determined by the disk diffusion method and a microdilution broth assay against six bacteria stains. The combinations of these essential oils with antibiotics were evaluated against two multi-drug-resistant bacteria strains: imipenem-resistant Acinetobacter baumannii (IRAB S3310) and methicillin-resistant Staphylococcus aureus (MRSA S19). The chemical analysis of M. pulegium essential oil revealed the presence of pulegone (74.8%) and neoisomenthol (10.0%). A. herba alba essential oil was characterized by camphor (32.0%), α-thujone (13.7%), 1,8-cineole (9.8%), ß-thujone (5.0%), bornéol (3.8%), camphene (3.6%), and p-cymene (2.1%). All strains tested except Pseudomonas aeruginosa were susceptible to these oils. The combinations of essential oils with antibiotics exerted synergism, antagonism, or indifferent effects. The best effect was observed with A. herba alba essential oil in association with cefoxitin (CX) against MRSA S19. However, for IRAB S3310, the strongest synergistic effect was observed with M. pulegium in association with amikacin (AK). This study demonstrated that M. pulegium and A. herba alba essential oils have antibacterial activities which could be potentiated by antibiotics especially in the case of IRAB S3310.


Asunto(s)
Acinetobacter baumannii/efectos de los fármacos , Antibacterianos/farmacología , Artemisia/química , Imipenem/farmacología , Mentha pulegium/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Aceites Volátiles/farmacología , Antioxidantes/farmacología , Cromatografía de Gases y Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Aceites de Plantas/farmacología
2.
Microb Drug Resist ; 27(5): 652-659, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-32991248

RESUMEN

Objectives: The aim of this study was to characterize the molecular mechanisms of carbapenem resistance in Klebsiella pneumoniae isolated from the urology department of Annaba hospital, Algeria. Methods: Between January 2015 and September 2017, 14 carbapenem-resistant K. pneumoniae strains were isolated during routine surveillance work at Ibn Roched hospital of Annaba, Algeria, from the urology department. Theses strains were recovered, and carbapenem resistance mechanisms were investigated. The strains were identified by using matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. Antibiotic susceptibility was assessed by using the Kirby-Bauer method, whereas minimum inhibitory concentration of imipenem/ertapenem and colistin was determined by Etest and broth microdilution methods, respectively. Carbapenem resistance determinants were studied by using PCR and sequencing methods and analyzed by BLAST against the Antibiotic Resistance Gene-ANNOTation (ARG-ANNOT) database. Clonal relationship of strains was performed by using multilocus sequence typing (MLST). Transferability of carbapenem resistance genes was assessed by conjugation and transformation experiments. Results: Fourteen carbapenem-resistant K. pneumoniae isolates were found to be resistant to the eight ß-lactam antibiotics tested (except to imipenem for two isolates). Carbapenemase production was positive for all isolates. Molecular characterization revealed that blaKPC-2 and blaOXA-48 genes were detected in 3 (21.4%) and 11 isolates (78.6%), respectively. Other ß-lactamases genes were identified, including blaCTX-M-15, blaSHV-1-or 12, and blaTEM-1. MLST revealed that the 14 isolates belonged to 2 different sequence types (STs), including ST101 (11 OXA-48-producing K. pneumoniae) and ST258 (3 KPC-2-producing K. pneumoniae). PCR amplifications for blaKPC-2 and blaOXA-48 carbapenemases genes performed on extracted plasmids, showed positive results, suggesting that both carbapenemase genes were probably borne by plasmids. Conclusion: We report here the first identification of KPC-2-producing K. pneumoniae ST258 in Algerian hospitals and an outbreak of OXA-48-producing K. pneumoniae isolates ST101 in the urology department of Ibn Roched hospital located in Annaba, Algeria.


Asunto(s)
Antibacterianos/farmacología , Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana Múltiple/genética , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , beta-Lactamasas/genética , Adulto , Anciano , Argelia/epidemiología , Infección Hospitalaria/microbiología , Femenino , Genes Bacterianos/genética , Humanos , Klebsiella pneumoniae/enzimología , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Plásmidos , Reacción en Cadena de la Polimerasa
3.
Microb Drug Resist ; 27(4): 492-500, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32208064

RESUMEN

Aim: We investigated the prevalence of carbapenemase-producing Enterobacteriaceae (CPE) in chicken meat in Western Algeria in 2017. Results: From February to July 2017, samples of chicken meat from three poultry farms in Western Algeria were screened for the presence of CPE. Strains were characterized with regard to antibiotic resistance, ß-lactamase content, Plasmid-mediated quinolone resistance, sulfonamide resistance genes, clonality (repetitive sequence-based profiles and multilocus sequence typing) and virulence traits. Of 181 samples analyzed, 29 (16.0%) carbapenemase-producing Klebsiella pneumoniae were detected. Twenty-three OXA-48-producers (79.3%) and six (20.7%) New Delhi metallo (NDM)-1-producers were observed. Clonality analysis showed three distinct lineages and clonal expansions of the OXA-48-producing K. pneumoniae ST48 and the NDM-1-producing K. pneumoniae ST101. These isolates harbored fimH, ureA, mrkD, entB, uge, and wabG. Neither capsular serotype genes nor hypermucoviscous phenotype were detected. Plasmid analysis confirmed that all these isolates harbored the transferable IncL and IncFIIK plasmids. Conclusions: This study reports the spread of OXA-48 and NDM-1-producing K. pneumoniae ST48 and ST101 in chicken meat in Western Algeria and demonstrates that food represents a reservoir of the carbapenemases encoding genes.


Asunto(s)
Antibacterianos/farmacología , Klebsiella pneumoniae/genética , Aves de Corral/microbiología , beta-Lactamasas/genética , Argelia/epidemiología , Animales , Pollos/microbiología , Farmacorresistencia Bacteriana Múltiple/genética
4.
Front Microbiol ; 11: 1422, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32765433

RESUMEN

In developed countries, hematological malignancies (HM) account for 8 to 10% of cancers diagnosed annually and one-third of patients with HM (HMP) are expected to die from their disease. The former wide spectrum "magic bullet," imipenem, has been ousted by the emergence of carbapenem resistant (CR) pathogens. In endemic areas, infections with CR-bacteria occur in vulnerable patients, notably in HMP, who suffer from high mortality related to infectious complications. In this work, we reviewed epidemiologic and clinical factors associated with CR-infections in adult HMP and data on CR-related mortality and antibiotic treatments in this population. We found that resistance profile of strains involved in HMP infections, mainly bacteremia, reflect local epidemiology. Significant risk factors for infections with CR-bacteria include sex male, age around 50 years old, acute leukemia, selvage chemotherapy, neutropenia, and digestive colonization by CR-bacteria. Mortality rate is high in HMP infected with CR-Enterobacteriaceae, more particularly in case of acute myeloid leukemia and unresolved neutropenia, due to inappropriate empiric management and delayed administration of targeted antibiotics, such as tigecycline, colistin, or new associations of active drugs. Thus, we developed an algorithm for clinicians, assessing the incremental risk for CR-bacterial infection occurrence and mortality in febrile HMP, to guide decisions related to empirical therapeutic strategies.

5.
Artículo en Inglés | MEDLINE | ID: mdl-31687131

RESUMEN

Background: The emergence of carbapenemase-producing (CP) Citrobacter freundii poses a significant threat to public health, especially in high-risk populations. In this study, whole genome sequencing was used to characterize the carbapenem resistance mechanism of three C. freundii clinical isolates recovered from fecal samples of patients with acute leukemia (AL) from Spain. Materials and methods: Twelve fecal samples, collected between 2013 and 2015 from 9 patients with AL, were screened for the presence of CP strains by selecting them on MacConkey agar supplemented with ertapenem (0.5 mg/L). Bacteria were identified by MALDI-TOF mass spectrometry and were phenotypically characterized. Whole genome sequencing of C. freundii isolates was performed using the MinION and MiSeq Illumina sequencers. Bioinformatic analysis was performed in order to identify the molecular support of carbapenem resistance and to study the genetic environment of carbapenem resistance encoding genes. Results: Three carbapenem-resistant C. freundii strains (imipenem MIC≥32 mg/L) corresponding to three different AL patients were isolated. Positive modified Carba NP test results suggested carbapenemase production. The genomes of each C. freundii tested were assembled into a single chromosomal contig and plasmids contig. In all the strains, the carbapenem resistance was due to the coproduction of OXA-48 and VIM-1 enzymes encoded by genes located on chromosome and on an IncHI2 plasmid, respectively. According to the MLST and the SNPs analysis, all strains belonged to the same clone ST169. Conclusion: We report in our study, the intestinal carrying of C. freundii clone ST169 coproducing OXA-48 and VIM-1 identified in leukemic patients.


Asunto(s)
Proteínas Bacterianas/genética , Citrobacter freundii/clasificación , Citrobacter freundii/genética , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/etiología , Genoma Bacteriano , Genómica , Leucemia/complicaciones , beta-Lactamasas/genética , Citrobacter freundii/efectos de los fármacos , Genómica/métodos , Humanos , Vigilancia en Salud Pública , España/epidemiología
6.
J Infect Chemother ; 25(8): 605-609, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31023570

RESUMEN

BACKGROUND: Bacterial infections in immunocompromised patients are associated with a high mortality and morbidity rate. In this high-risk group, the presence of multidrug-resistant (MDR) bacteria, particularly bacteria that harbor a transferable antibiotic resistance gene, complicates the management of bacterial infections. In this study, we investigated the presence of the transferable colistin resistance mcr genes in patients with leukemia in Spain. METHODS: 217 fecal samples collected in 2013-2015 from 56 patients with acute leukemia and colonized with MDR Enterobacteriaceae strains, were screened on September 2017 for the presence of the colistin resistance mcr genes (mcr-1 to -5) by multiplex PCR. mcr positive strains selected on LBJMR and MacConkey supplemented with colistin (2 µg/ml) media were phenotypically and molecularly characterized by antimicrobial susceptibility testing, minimum inhibitory concentration, multilocus sequence typing and plasmid characterization. RESULTS: Among 217 fecal samples, 5 samples collected from 3 patients were positive for the presence of the mcr-1 colistin-resistance gene. Four Escherichia coli strains were isolated and exhibited resistance to colistin with MIC = 4 µg/ml. Other genes conferring the resistance to ß-lactam antibiotics have also been identified in mcr-1 positive strains, including blaTEM-206 and blaTEM-98. Three different sequence types were identified, including ST1196, ST140 and ST10. Plasmid characterization allowed us to detect the mcr-1 colistin resistance gene on conjugative IncP plasmid type. CONCLUSION: To the best of our knowledge, we have identified the mcr-1 gene for the first time in leukemia patients in Spain. In light of these results, strict measures have been implemented to prevent its dissemination.


Asunto(s)
Colistina/farmacología , Farmacorresistencia Bacteriana/genética , Proteínas de Escherichia coli/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Leucemia/microbiología , Plásmidos/genética , Antibacterianos/farmacología , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Humanos , Pruebas de Sensibilidad Microbiana/métodos , Persona de Mediana Edad , España , beta-Lactamasas/genética
7.
Microb Drug Resist ; 25(1): 63-71, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30129868

RESUMEN

OBJECTIVES: Genomic and phenotypic characterization of resistance mechanisms to carbapenems and colistin in Klebsiella pneumoniae strains isolated from the Shaare Zedek Medical Center (Jerusalem, Israel). RESULTS: The 15 K. pneumoniae isolates studied present a high level of resistance to the antibiotics tested. Microbiological tests revealed production of carbapenemase enzymes by all isolates. ABI SOLiD sequencing of K. pneumoniae genomes generated between 5,033,665 and 8,876,861 million reads per genome. The genomic study revealed that carbapenem resistance was mediated by production of the KPC-3 enzyme in 13 isolates and NDM-1 enzyme in the remaining 2 isolates. In addition, colistin resistance was induced either by a missense mutation in the mgrB gene or inactivation of mgrB by an IS5-like insertion sequence. The mobile genetic element, transposon Tn4401, was identified in all genomes harboring the blaKPC gene. The 15 K. pneumoniae strains were assigned to 4 different sequence types, including ST16, ST76, ST258, and ST512. CONCLUSION: In this study, we report the usefulness of whole-genome sequencing in detection of antibiotic resistance mechanisms and in highlighting the emergence of the carbapenem and colistin-resistant K. pneumoniae clone ST512 in Israeli hospitals.


Asunto(s)
Carbapenémicos/farmacología , Colistina/farmacología , Farmacorresistencia Bacteriana/genética , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/aislamiento & purificación , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Elementos Transponibles de ADN/genética , Farmacorresistencia Bacteriana/efectos de los fármacos , Genes Bacterianos/genética , Hospitales , Humanos , Israel , Klebsiella pneumoniae/genética , Pruebas de Sensibilidad Microbiana/métodos , Mutación Missense/genética , beta-Lactamasas/genética
8.
BMC Microbiol ; 18(1): 107, 2018 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-30185164

RESUMEN

BACKGROUND: Acinetobacter baumannii is an important opportunistic pathogen that is rapidly evolving towards multidrug resistance and is responsible for life-threatening infections. Carbapenems are commonly used to treat A. baumannii infections but the emergence of carbapenemase encoding genes, such as blaOXA-23-like, blaOXA-24-like, blaOXA-58-like, and blaNDM has been reported. Moreover, several studies have reported the co-occurrence of two distinct carbapenemases in some isolates. The aim of the present study is to demonstrate whether the phenomenon of co-occurrence of two distinct carbapenemase encoding genes in a single isolate still exists. RESULTS: We studied six strains of A. baumannii including one harboring blaOXA-23-like and blaOXA-24-like genes and five with blaOXA-23-like and blaNDM genes. One colony of each strain was inoculated in sterile water and diluted ten-fold. Each dilution was cultivated on trypticase soy agar plates for 24 h at 37 °C and the isolated bacteria were analyzed. For two of the six tested strains, we identified two different populations of A. baumannii, each with a different carbapenemase, genes encoding aminoglycoside modifying enzymes, resistance phenotype, and clonal type. In addition, the two different populations had the same aspect on the agar plate. CONCLUSIONS: Here, we demonstrate that A. baumannii infections could be linked to multiple clones harboring different carbapenemase encoding genes in the same sample. In addition, we describe an easy method of verifying the presence of co-occurrence of carbapenemase in one isolate.


Asunto(s)
Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/enzimología , Proteínas Bacterianas/metabolismo , beta-Lactamasas/metabolismo , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/genética , Aminoglicósidos/farmacología , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Carbapenémicos/farmacología , Humanos , Pruebas de Sensibilidad Microbiana , beta-Lactamasas/genética
10.
Infect Drug Resist ; 11: 735-742, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29844691

RESUMEN

OBJECTIVES: The aims of this study were to investigate the occurrence of carbapenem-resistant Gram-negative bacilli (GNB) isolated from inpatients and outpatients in Algeria between July and September 2015, and to screen their resistance mechanisms and genetic relatedness. MATERIALS AND METHODS: A total of 68 non-redundant isolates were identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) antibiotic susceptibility testing was performed using disk diffusion and Etest methods. Carbapenemase activity was carried out using modified Carba NP test, EDTA assay, and the modified Hodge test. Molecular characterization of carbapenemases and extended-spectrum ß-lactamase (ESBL) genes were detected by standard PCR and sequencing. Genotyping of carbapenem-resistant isolates was performed by multilocus sequence typing (MLST) analysis. RESULTS: Of the 68 GNB isolates, 13 (19%) showed reduced susceptibility to carbapenems, including, four Klebsiella pneumoniae, one Escherichia coli, six Acinetobacter baumannii, and two Pseudomonas aeruginosa. blaOXA-48 gene was detected in the five Enterobacteriaceae isolates, and blaOXA-23 was identified in all A. baumannii isolates. OprD mutations were revealed in the two P. aeruginosa isolates. A total of 11 out of the 13 carbapenem-resistant GNB were detected in inpatients, and the two remaining strains were isolated from outpatients. Molecular typing showed the presence of four sequence types (STs) among the OXA-48-producing K. pneumoniae isolates: ST101, ST147, ST163, and ST2017. ST533 was identified for the OXA-48 producing E. coli isolate. All of the A. baumannii and P. aeruginosa were assigned to the international clonal lineages ST2 and ST654, respectively. CONCLUSION: This study reports the first detection of the epidemic multidrug-resistant lineage, K. pneumoniae ST147 coproduced blaOXA-48 and ESBL genes in Algeria and represents the first description of OXA-48-producing E. coli ST533 and K. pneumoniae ST163 and ST2017. In addition, this study describes for the first time the emergence of OXA-48-producing E. coli and K. pneumoniae in the community in Algeria, leading to major problems for managing microbial infections.

11.
Stand Genomic Sci ; 13: 8, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29682169

RESUMEN

We report the properties of a draft genome sequence of the bacterium Fermentimonas caenicola strain SIT8 (= CSUR P1560). This strain, whose genome is described here, was isolated from the fecal flora of a healthy 28-month-old Senegalese boy. Strain SIT8 is a facultatively anaerobic Gram-negative bacillus. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,824,451-bp long (1 chromosome but no plasmid) contains 2354 protein-coding and 46 RNA genes, including four rRNA genes.

12.
Microb Drug Resist ; 24(3): 337-345, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28799835

RESUMEN

The aim of the present study was to screen for the presence of carbapenemase-producing Enterobacteriaceae (CPE) isolates from wild boars and Barbary macaques in Algeria. Fecal samples were collected from wild boars (n = 168) and Barbary macaques (n = 212), in Bejaia, Algeria, between September 2014 and April 2016. The isolates were identified and antimicrobial susceptibility was determined. Carbapenem resistance determinants were studied using PCR and sequencing, while clonal relatedness was performed using multilocus sequence typing (MLST). PCR was used to investigate certain virulence genes. Three CPE isolates from three different samples (1.8%) recovered from wild boars were identified as Escherichia coli (two isolates) and Klebsiella pneumoniae (one isolate). These isolates were resistant to amoxicillin, amoxicillin-clavulanate, tobramycin, ertapenem, and meropenem. The results of PCR and sequencing analysis showed that all three isolates produced the OXA-48 enzyme. The MLST showed that the two E. coli isolates were assigned to the same sequence type, ST635, and belonged to phylogroup A, whereas K. pneumoniae strain belonged to ST13. The K. pneumoniae strain was positive for multiple virulence factors, whereas no virulence determinants were found in E. coli isolates. This is the first report of OXA-48-producing Enterobacteriaceae in wild animals from Algeria and Africa.


Asunto(s)
Infecciones por Enterobacteriaceae/veterinaria , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Klebsiella pneumoniae/genética , Resistencia betalactámica/genética , beta-Lactamasas/genética , Argelia/epidemiología , Animales , Antibacterianos/farmacología , Carbapenémicos/farmacología , ADN Bacteriano/genética , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/microbiología , Escherichia coli/clasificación , Escherichia coli/efectos de los fármacos , Proteínas de Escherichia coli/metabolismo , Heces/microbiología , Expresión Génica , Humanos , Klebsiella pneumoniae/clasificación , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/patogenicidad , Macaca , Tipificación de Secuencias Multilocus , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Serogrupo , Sus scrofa , Virulencia , beta-Lactamasas/metabolismo
13.
Microb Drug Resist ; 24(7): 890-895, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29227182

RESUMEN

BACKGROUND: The aim of the present study was to screen for the presence of mcr-1 gene in Enterobacteriaceae isolated from Barbary macaques (Macaca sylvanus) in Algeria. MATERIALS AND METHODS: From January to April 2016, a total of 86 fresh stool samples from Barbary macaques were collected in the Toudja forest (Bejaia, Algeria). After isolation, the isolates were identified by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. Antibiotic susceptibility was determined by disk diffusion method, and minimum inhibitory concentration (MIC) of colistin was determined by E-test. Polymerase chain reaction (PCR) and sequencing were used to identify mcr-1gene. The sequence type (ST) was done using multilocus sequence typing. Phylogenetic groups of Escherichia coli and the presence of virulence genes were determined by PCR. Transfer of mcr-1 and extended-spectrum ß-lactamase genes was assessed by conjugation and transformation experiments. RESULTS: E. coli M076 isolate was found resistant to colistin with a MIC of 4 mg/L and to other antibiotic families, including ß-lactams, aminoglycosides, and fluoroquinolones. PCR and sequencing revealed that this isolate harbored the mcr-1, blaCTX-M-15, blaTEM-1, and qnrB19 genes. This isolate was assigned to ST405, belonged to phylogroup D, and contains only one virulence gene fyuA (siderophore uptake receptor). Neither transconjugants nor transformants were obtained for this isolate. CONCLUSION: In this study, we report the detection of mcr-1 gene producing E. coli from wild animals.


Asunto(s)
Colistina/farmacología , Farmacorresistencia Bacteriana/genética , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Genes Bacterianos/genética , Plásmidos/genética , Argelia , Animales , Animales Salvajes , Antibacterianos/farmacología , Farmacorresistencia Bacteriana/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana/métodos , Tipificación de Secuencias Multilocus/métodos , Filogenia , beta-Lactamasas/genética
14.
J Glob Antimicrob Resist ; 13: 70-73, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29175034

RESUMEN

OBJECTIVES: In this study, the presence of carbapenemase genes in Shewanella xiamenensis strains isolated from river water in Béjaïa, Algeria, was investigated. METHODS: Four isolates of S. xiamenensis were isolated from water from Soummam River. The isolates were identified by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS) and sequencing of the 16S rRNA and gyrB genes. Isolates were subjected to antimicrobial susceptibility testing. Carbapenemase production was screened using phenotypic tests. PCR and sequencing were used to identify carbapenemase genes in the isolates. The genetic context of the blaOXA-48-like gene was investigated by sequencing the whole genome of strain AS58. RESULTS: All four S. xiamenensis strains harboured blaOXA-48-like genes. They exhibited different resistance patterns and had imipenem minimum inhibitory concentrations (MICs) of ≥0.5mg/L. Sequencing of blaOXA-48-like genes from the S. xiamenensis isolates showed that two strains harboured blaOXA-181, one strain harboured blaOXA-199 and one strain exhibited a new variant of the blaOXA-48-like gene, named blaOXA-538. This new variant shared 98% nucleotide identity with blaOXA-162, with three amino acid changes (G201A, A213G and I219F). Conjugation assays with Escherichia coli J53 recipient were performed but no transconjugants were obtained. Analysis of the genome of AS58 Touati strain confirmed the chromosomal location of the blaOXA-538 gene. CONCLUSION: This study showed that environmental water holds a diversity of S. xiamenensis strains harbouring blaOXA-48-like genes and may play an important role in the dissemination and spread of these genes from the environment to humans.


Asunto(s)
Proteínas Bacterianas/genética , Ríos/microbiología , Shewanella/enzimología , Shewanella/aislamiento & purificación , beta-Lactamasas/genética , Argelia , Proteínas Bacterianas/análisis , Análisis por Conglomerados , Girasa de ADN/genética , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Genoma Bacteriano , Humanos , Pruebas de Sensibilidad Microbiana , Filogenia , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Shewanella/genética , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , beta-Lactamasas/análisis
15.
Microb Drug Resist ; 24(2): 136-141, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28691891

RESUMEN

Acinetobacter baumannii is an important opportunistic and multidrug-resistant pathogen responsible for nosocomial infections in health facilities. The aim of this study was to characterize the molecular mechanisms of carbapenem resistance in A. baumannii isolates isolated from Mohamed Kassab Orthopedic Institute in Tunis, Tunisia. Twenty-five imipenem-resistant A. baumannii clinical isolates collected between 2013 and 2016 were identified using API 20NE and were confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). Carbapenemase activity was detected using microbiological tests and PCR. The epidemiological relatedness of the isolates was studied using multilocus sequence typing (MLST). The isolates were resistant to all antibiotics tested with increased minimum inhibitory concentration values (>32 mg/L). The microbiological tests showed that the 25 A. baumannii were positive for modified Hodge test and for the Carba NP test; however, ß-lactamase activity was not inhibited by EDTA. All the isolates harbored the naturally occurring blaOXA-51-like gene and the blaOXA-23-like carbapenemase gene. Among these isolates, one isolate coexpressed the blaOXA-58 gene. MLST revealed several sequence types (STs) with the predominance of ST2 imipenem-resistant A. baumannii (14/25; 56%). In this study we report the prevalence of ST2 imipenem resistance and for the first time the coexpression of blaOXA-23 and blaOXA-58 in clinical isolates of A. baumannii in a Tunisian hospital.


Asunto(s)
Infecciones por Acinetobacter/epidemiología , Acinetobacter baumannii/genética , Infección Hospitalaria/epidemiología , Regulación Bacteriana de la Expresión Génica , beta-Lactamasas/genética , Infecciones por Acinetobacter/tratamiento farmacológico , Infecciones por Acinetobacter/microbiología , Acinetobacter baumannii/clasificación , Acinetobacter baumannii/efectos de los fármacos , Acinetobacter baumannii/aislamiento & purificación , Adulto , Antibacterianos/farmacología , Infección Hospitalaria/tratamiento farmacológico , Infección Hospitalaria/microbiología , Femenino , Hospitales , Humanos , Imipenem/farmacología , Incidencia , Masculino , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Filogenia , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Túnez/epidemiología , Resistencia betalactámica/genética , beta-Lactamasas/metabolismo
16.
J Clin Microbiol ; 55(10): 3113-3122, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28794176

RESUMEN

Kingella kingae is an important invasive pathogen in early childhood. The organism elaborates an RTX toxin presumably restricted to this species. Consequently, real-time quantitative PCR (qPCR) assays targeting the RTX locus have been developed in recent years and are gaining increasing use for the molecular diagnosis of K. kingae infections. However, the present study shows that Kingella negevensis, a Kingella species newly identified in young children, harbors an identical Kingella RTX locus, raising the question of whether K. negevensis can be misidentified as K. kingae by clinical microbiology laboratories. In silico comparison of Kingella sp. RTX and groEL genes and in vitro studies provided evidence that targeting the rtxA and rtxB genes could not differentiate between strains of K. kingae and K. negevensis, whereas targeting the groEL gene could. This prompted the design of a highly specific and sensitive qPCR assay targeting K. negevensis groEL (kngroEL). Ninety-nine culture-negative osteoarticular specimens from 99 children younger than 4 years of age were tested with a conventional 16S rRNA gene-based broad-range PCR assay and Kingella-specific rtxB, K. kingae-specific groEL (kkgroEL), and kngroEL qPCR assays. Forty-two specimens were rtxB positive, including 41 that were also kkgroEL positive and 1 (the remaining one) that was kngroEL positive. Thus, this study discloses an invasive infection caused by K. negevensis in humans and demonstrates that targeting the RTX locus cannot be used for the formal diagnosis of K. kingae infections. These findings stress the need for further studies on the epidemiology of asymptomatic carriage and invasive infections caused by K. negevensis in humans.


Asunto(s)
Artritis Infecciosa/diagnóstico , Toxinas Bacterianas/genética , Kingella kingae/clasificación , Kingella kingae/genética , Infecciones por Neisseriaceae/diagnóstico , Osteomielitis/diagnóstico , Artritis Infecciosa/microbiología , Toxinas Bacterianas/metabolismo , Chaperonina 60/genética , Preescolar , Femenino , Humanos , Lactante , Masculino , Infecciones por Neisseriaceae/microbiología , Osteomielitis/microbiología , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genética
17.
J Glob Antimicrob Resist ; 10: 148-153, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28732788

RESUMEN

PURPOSE: The aim of this study is to characterize the molecular support of antibiotic resistance in MDR Klebsiella pneumoniae recovered from inanimate surfaces between March 2012 to February 2014 in three teaching hospitals (Setif, Bejaia and Constantine) in Algeria. RESULTS: Forty-four K. pneumoniae producing ESBL were detected and blaCTX-M-15 and blaCTX-M-3 were detected respectively in 41 and 3 isolates. These K. pneumoniae isolates producing ESBL were also resistant to gentamicin (87%), tobramicin (87%), ciprofloxacin (66%) and ofloxacin (62%). Aminoglycosides resistance genes detected were 16S rRNA methylase (armA), aminoglycoside acetyl-transferase (aac(6')-Ib), aminoglycoside nucleotidyl-transferase (aadA2) and aminoglycoside, phosphoryl-transferase (ant3″Ih-aac(6')-IId). Plasmid-mediated quinolone resistance (PMQR) genes detected were aac(6')-Ib-cr (34 isolates) and qnrB genes in (34 isolates). Multilocus sequence typing (MLST) resulted in 12 different sequence types (STs) regrouped into 5 clonal complexes (CC147, CC17, CC37, CC2 and CC23), one clonal group (CG485) and 4 singletons (ST1426, ST405, ST1308, ST873). CONCLUSION: Here, we report the detection of the ESBLs encoding gene linked with plasmid-mediated quinolone resistance (PMQR) and aminoglycosides resistance recovered from inanimate surfaces in hospital environment.


Asunto(s)
Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana Múltiple/genética , Klebsiella pneumoniae/genética , beta-Lactamasas/genética , Acetiltransferasas/genética , Argelia/epidemiología , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Hospitales , Humanos , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Metiltransferasas/genética , Pruebas de Sensibilidad Microbiana , Epidemiología Molecular , Tipificación Molecular , Tipificación de Secuencias Multilocus , Plásmidos
18.
Int J Syst Evol Microbiol ; 67(7): 2370-2376, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28699877

RESUMEN

We herein report the isolation and characterization of 21 Gram-stain-negative strains cultivated from the oropharynx of healthy children in Israel and Switzerland. Initially described as small colony variants of Kingella kingae, phenotypic analysis, biochemical analysis, phylogenetic analysis based on sequencing of the partial 16S rRNA gene and five housekeeping genes (abcZ, adk, G6PD, groEL and recA), and whole genome sequencing and comparison between members of the genera Kingella and Neisseria provided evidence for assigning them to the genus Kingella. Cellular fatty acids included important amounts of C12 : 0, C14 : 0, C16 : 0 and C16 : 1n7. Digital DNA-DNA hybridization between the isolates Sch538T and K. kingae ATCC 23330T revealed relatedness of 19.9 %. Comparative analysis of 16S rRNA gene sequences available in GenBank allowed matches to strains isolated in the USA, suggesting a wider geographical distribution. A novel species named Kingella negevensis sp. nov. is proposed, as most strains have been isolated in the Negev, a desert region of southern Israel. The type strain is Sch538T (=CCUG 69806T=CSUR P957).


Asunto(s)
Kingella/clasificación , Orofaringe/microbiología , Filogenia , Técnicas de Tipificación Bacteriana , Composición de Base , Niño , ADN Bacteriano/genética , Ácidos Grasos/química , Genes Bacterianos , Humanos , Israel , Kingella/genética , Kingella/aislamiento & purificación , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Suiza
19.
BMC Vet Res ; 13(1): 132, 2017 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-28506272

RESUMEN

BACKGROUND: The aims of this study were to investigate Salmonella contamination in broiler chicken farms and slaughterhouses, to assess the antibiotic resistance profile in avian and human Salmonella isolates, and to evaluate the relationship between avian and human Extended Spectrum ß-Lactamase (ESBL)-producing isolates. Salmonella was screened in different sample matrices collected at thirty-two chicken farms and five slaughterhouses. The human isolates were recovered from clinical specimens at the University Teaching Hospital of Constantine (UTH). All suspected colonies were confirmed by MALDI-TOF (Matrix Assisted Laser Desorption Ionization Time OF light) and serotyped. Susceptibility testing against 13 antibiotics including, amoxicillin/clavulanic acid, ticarcillin, cefoxitin, cefotaxime, aztreonam, imipenem, ertapenem, gentamicin, amikacin, ciprofloxacin, colistin, trimethoprim/sulfamethoxazole and fosfomycin, was performed using the disk diffusion method on Mueller-Hinton agar. ESBL-production was screened by the double-disk synergy test and confirmed by molecular characterization using PCR (polymerase chain reaction) amplification and sequencing of ESBL encoding genes. Clonality of the avian and human strains was performed using the Multi Locus Sequencing Typing method (MLST). RESULTS: Forty-five isolated avian Salmonella strains and 37 human collected ones were studied. Five S. enterica serotypes were found in avian isolates (mainly Kentucky) and 9 from human ones (essentially Infantis). 51.11% and 26.6% of the avian isolates were resistant to ciprofloxacin and cefotaxime, respectively, whereas human isolates were less resistant to these antibiotics (13.5% to ciprofloxacin and 16.2% to cefotaxime). Eighteen (12 avian and 6 human) strains were found to produce ESBLs, which were identified as bla CTX-M-1 (n = 12), bla CTX-M-15 (n = 5) and bla TEM group (n = 8). Interestingly, seven of the ESBL-producing strains (5 avian and 2 human) were of the same ST (ST15) and clustered together, suggesting a common origin. CONCLUSION: The results of the combined phenotypic and genotypic analysis found in this study suggest a close relationship between human and avian strains and support the hypothesis that poultry production may play a role in the spread of multidrug-resistant Salmonella in the human community within the study region.


Asunto(s)
Salmonella/aislamiento & purificación , beta-Lactamasas/biosíntesis , Mataderos , Argelia , Alimentación Animal/microbiología , Animales , Antibacterianos/farmacología , Pollos , Vivienda para Animales , Humanos , Pruebas de Sensibilidad Microbiana , Prevalencia , Salmonella/clasificación , Salmonella/enzimología , Salmonella/metabolismo
20.
Water Res ; 120: 185-189, 2017 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-28486169

RESUMEN

The spread of carbapenemase-producing Enterobacteriaceae (CPE) is a significant problem for healthcare worldwide. The prevalence of carbapenem-resistant Enterobacteriaceae (CPE) in water environments in Algeria are unknown. The aim of this study was to screen for the presence of CPE isolates in the Soummam River in Bejaia, Algeria. Isolates of Enterobacteriaceae recovered from twelve samples of river water and showing reduced susceptibility to carbapenems were included in this study. The isolates were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Isolates were subjected to antimicrobial susceptibility testing and the modified Carba NP test. Carbapenemase and extended-spectrum ß-lactamase (ESBL) determinants were studied by PCR amplification and sequencing. The clonal relatedness between isolates was studied by Multilocus Sequence Typing (MLST) method. A total of 20 carbapenem-resistant Enterobacteriaceae strains were included in this study, identified as Escherichia coli (n = 12), Klebsiella pneumoniae (n = 3), Raoultella ornithinolytica (n = 3), Citrobacter freundii (n = 1) and Citrobacter braakii (n = 1). Carbapenemase genes identified in this study included blaOXA-48, observed in 17 isolates (9 E. coli, 3 K. pneumoniae, 3 R. ornithinolytica, 1 C. freundii and 1 C. braakii), and blaOXA-244, a variant of blaOXA-48, was found in three E. coli isolates. MLST showed that 12 E. coli strains belonged to six different sequence types (ST559, ST38, ST212, ST3541, 1972 and ST2142), and we identified three different STs in K. pneumoniae isolates, including ST133, ST2055, and a new sequence type: ST2192. This study showed the presence of OXA-48-like-producing Enterobacteriaceae in water environments and highlighted the potential role of aquatic environments as reservoirs of clinically relevant antimicrobial-resistant bacteria, with the potential to spread throughout the community.


Asunto(s)
Enterobacteriaceae , Oxitocina/metabolismo , Ríos , Argelia , Antibacterianos , Proteínas Bacterianas , Escherichia coli , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , beta-Lactamasas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...