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1.
J Fish Dis ; 42(10): 1409-1417, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31424570

RESUMEN

Bacillary necrosis of Pangasius (BNP), caused by Edwardsiella ictaluri, is one of the most devastating diseases in striped catfish farming. To date, quantitative genetic inheritance of BNP resistance is not known in striped catfish Pangasianodon hypophthalmus. The main aim of this study was to estimate genetic parameters for BNP resistance in a breeding population of striped catfish undergoing four generations of selection for high growth. Specifically, the study examined whether BNP resistance is heritable to enable family selection and whether genetic improvement for enhanced BNP resistance may have detrimental effects on growth and survival rate. To test these hypotheses, 720 full- and half-sib families were challenged with E. ictaluri pathogen using injection and cohabitation methods over four years, from 2010 to 2012 and 2015. In total, the data included 398,234 animals in the pedigree, from which 18,849 animals had disease challenge test records and 39,103 siblings had growth performance. Both univariate and bivariate sire-dam linear and threshold mixed models were used to estimate (co)variance components for BNP resistance, survivals and growth traits. The estimates of heritability for the BNP resistance recorded as death or survival were low regardless of models used (0.10-0.16), whereas survival time (days post-challenge test) showed moderate heritability (0.35). The survival rate during hapa rearing had medium heritability (0.33-0.52). The genetic correlations of BNP resistance with body weight and survival were all positive (0.03-0.53), suggesting that selection of increased BNP resistance may have positive impacts on growth and survival traits, and these traits could be easily improved simultaneously in the selective breeding programme for striped catfish.


Asunto(s)
Cruzamiento , Bagres , Resistencia a la Enfermedad/genética , Infecciones por Enterobacteriaceae/veterinaria , Enfermedades de los Peces/genética , Animales , Edwardsiella ictaluri/fisiología , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Enfermedades de los Peces/microbiología
2.
Biomed Res Int ; 2019: 6736897, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31467906

RESUMEN

The aim of this study was to investigate the mechanisms responsible for resistance to antimicrobials in a collection of enterobacterial isolates recovered from two hospitals in Saudi Arabia. A total of six strains isolated from different patients showing high resistance to carbapenems was recovered in 2015 from two different hospitals, with four being Klebsiella pneumoniae and two Enterobacter cloacae. All isolates except one K. pneumoniae were resistant to tigecycline, but only one K. pneumoniae was resistant to colistin. All produced a carbapenemase according to the Carba NP test, and all were positive for the EDTA-disk synergy test for detection of MBL. Using PCR followed by sequencing, the four K. pneumoniae isolates produced the carbapenemase NDM-1, while the two E. cloacae isolates produced the carbapenemase VIM-1. Genotyping analysis by Multilocus Sequence Typing (MLST) showed that three out of the four K. pneumoniae isolates were clonally related. They had been recovered from the same hospital and belonged to Sequence Type (ST) ST152. In contrast, the fourth K. pneumoniae isolate belonged to ST572. Noticeably, the NDM-1-producing K. pneumoniae additionally produced an extended-spectrum ß-lactamase (ESBL) of the CTX-M type, together with OXA-1 and TEM-1. Surprisingly, the three clonally related isolates produced different CTX-M variants, namely, CTX-M-3, CTX-M-57, and CTX-M-82, and coproduced QnrB, which confers quinolone resistance, and the 16S rRNA methylase RmtC, which confers high resistance to all aminoglycosides. The AAC(6')-Ib acetyltransferase was detected in both K. pneumoniae and E. cloacae. Mating-out assays using Escherichia coli as recipient were successful for all isolates. The bla NDM-1 gene was always identified on a 70-kb plasmid, whereas the bla VIM-1 gene was located on either a 60-kb or a 150-kb plasmid the two E. cloacae isolates, respectively. To the best of our knowledge, this is the first report of the coexistence of an MBL (NDM-1), an ESBL (CTX-M), a 16S rRNA methylase (RmtC), an acetyltransferase (AAC[6']-Ib), and a quinolone resistance enzyme (QnrB) in K. pneumoniae isolates recovered from different patients during an outbreak in a Saudi Arabian hospital.


Asunto(s)
Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana/genética , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Infecciones por Klebsiella/tratamiento farmacológico , beta-Lactamasas/genética , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Carbapenémicos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , Enterobacter cloacae/efectos de los fármacos , Enterobacter cloacae/genética , Enterobacter cloacae/patogenicidad , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Femenino , Humanos , Infecciones por Klebsiella/genética , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/patogenicidad , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , ARN Ribosómico 16S/genética , Arabia Saudita/epidemiología
3.
Malays J Pathol ; 41(2): 139-148, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31427549

RESUMEN

INTRODUCTION: OXA-48, a carbapenem-hydrolysing class D ß-lactamase, and its variant, OXA-181, are increasingly reported worldwide. This study aimed to describe the prevalence and distribution of OXA-48 and OXA-181 carbapenem-resistant Enterobacteriaceae (CRE) in a tertiary medical centre in Malaysia. MATERIALS & METHODS: A total of 13,098 Enterobacteriaceae isolates from various clinical samples were sent to our laboratory between January 2011 and December 2012. Of these, 90 demonstrated reduced susceptibility to at least one carbapenem and were included in this study. Only 88 isolates were successfully subcultured on blood agar (BA). Another 2 isolates failed to grow and were excluded. Of the 88, 2 isolates had the same identification number (repetitive isolates); therefore, 1 isolate was excluded from further analyses. Only 87 isolates were subjected to molecular detection of the blaOXA-48 and blaOXA-181 genes by polymerase chain reaction. RESULTS: Eighty-seven non-repetitive isolates grew following subculture on BA. Of these, 9 (10.34%) were positive for OXA-48 (7 Klebsiella pneumoniae, 2 Escherichia coli). Each isolate originated from different patients. All patients had a history of treatment with at least one cephalosporin and/or carbapenem prior to the isolation of OXA-48 CRE. OXA-181 was detected in one (1.15%) out of the 87 isolates; CONCLUSIONS: The prevalence of OXA-48 and OXA-181 CRE among all Enterobacteriaceae isolates in our institution is 0.069% and 0.008%, respectively. Nevertheless, our findings suggest that OXA-48 and OXA-181 carbapenemases appear to be important and possibly under-recognised causes of carbapenem resistance in Malaysia.


Asunto(s)
Enterobacteriaceae Resistentes a los Carbapenémicos/enzimología , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Infecciones por Enterobacteriaceae/genética , beta-Lactamasas/genética , Adolescente , Adulto , Proteínas Bacterianas/genética , Estudios Transversales , Infecciones por Enterobacteriaceae/enzimología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
4.
PLoS Pathog ; 15(6): e1007898, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31251784

RESUMEN

Attaching/Effacing (A/E) bacteria include human pathogens enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC), and their murine equivalent Citrobacter rodentium (CR), of which EPEC and EHEC are important causative agents of foodborne diseases worldwide. While A/E pathogen infections cause mild symptoms in the immunocompetent hosts, an increasing number of studies show that they produce more severe morbidity and mortality in immunocompromised and/or immunodeficient hosts. However, the pathogenic mechanisms and crucial host-pathogen interactions during A/E pathogen infections under immunocompromised conditions remain elusive. We performed a functional screening by infecting interleukin-22 (IL-22) knockout (Il22-/-) mice with a library of randomly mutated CR strains. Our screen reveals that interruption of the espF gene, which encodes the Type III Secretion System effector EspF (E. coli secreted protein F) conserved among A/E pathogens, completely abolishes the high mortality rates in CR-infected Il22-/- mice. Chromosomal deletion of espF in CR recapitulates the avirulent phenotype without impacting colonization and proliferation of CR, and EspF complement in ΔespF strain fully restores the virulence in mice. Moreover, the expression levels of the espF gene are elevated during CR infection and CR induces disruption of the tight junction (TJ) strands in colonic epithelium in an EspF-dependent manner. Distinct from EspF, chromosomal deletion of other known TJ-damaging effector genes espG and map failed to impede CR virulence in Il22-/- mice. Hence our findings unveil a critical pathophysiological function for EspF during CR infection in the immunocompromised host and provide new insights into the complex pathogenic mechanisms of A/E pathogens.


Asunto(s)
Proteínas Bacterianas/inmunología , Proteínas Portadoras/inmunología , Citrobacter rodentium/inmunología , Infecciones por Enterobacteriaceae/inmunología , Huésped Inmunocomprometido , Mucosa Intestinal/inmunología , Uniones Estrechas/inmunología , Animales , Proteínas Bacterianas/genética , Proteínas Portadoras/genética , Línea Celular , Citrobacter rodentium/genética , Citrobacter rodentium/patogenicidad , Colon/inmunología , Colon/microbiología , Colon/patología , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/patología , Interleucinas/deficiencia , Interleucinas/inmunología , Mucosa Intestinal/microbiología , Mucosa Intestinal/patología , Ratones , Ratones Noqueados , Uniones Estrechas/genética , Uniones Estrechas/patología
5.
Indian J Med Res ; 149(2): 185-191, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-31219082

RESUMEN

Background & objectives: The escalation in carbapenem resistance among Enterobacteriaceae has resulted in a lack of effective therapeutic alternatives. Older antimicrobials, fosfomycin, nitrofurantoin and colistin for urinary tract infections (UTIs) caused by carbapenem-resistant Enterobacteriaceae (CRE) may be effective treatment options. The objectives of this study were to evaluate the utility of fosfomycin, nitrofurantoin and colistin in treating UTI caused by CRE and molecular characterization of the plasmid-mediated carbapenem resistance mechanisms. Methods: Consecutive, non-duplicate isolates of CR Escherichia coli and Klebsiella spp. from urine cultures were included (n=150). Minimum inhibitory concentrations (MIC) were determined by E-test (fosfomycin and nitrofurantoin) and broth microdilution (colistin). Efficacy ratios were derived by dividing susceptibility breakpoints by observed MIC values of the drugs for the isolates. Isolates were screened for genes coding for carbapenemases using multiplex PCR. Fosfomycin, nitrofurantoin and colistin-resistant isolates were screened for plasmid-borne resistance genes fos A3, oqx AB and mcr-1, respectively using PCR. Results: Among E. coli, 98.9, 56 and 95 per cent isolates were susceptible to fosfomycin, nitrofurantoin and colistin, respectively, while 94 and 85 per cent of Klebsiella spp. were susceptible to fosfomycin and colistin, respectively. The efficacy ratios indicated fosfomycin as the drug of choice for UTI caused by CR E. coli and Klebsiella spp., followed by colistin. The blaNDM gene was most common, followed by blaOXA48-like. Plasmid-borne genes encoding resistance to fosfomycin, nitrofurantoin and colistin were absent. Interpretation & conclusions: With increasing resistance against the current treatment options, older drugs may emerge as effective options. Molecular screening of resistant isolates is essential to prevent the spread of plasmid-borne resistance against these drugs.


Asunto(s)
Proteínas Bacterianas/genética , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Infecciones Urinarias/tratamiento farmacológico , beta-Lactamasas/genética , Proteínas Bacterianas/efectos de los fármacos , Enterobacteriaceae Resistentes a los Carbapenémicos/enzimología , Enterobacteriaceae Resistentes a los Carbapenémicos/patogenicidad , Colistina/uso terapéutico , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Fosfomicina/uso terapéutico , Humanos , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/patogenicidad , Pruebas de Sensibilidad Microbiana , Nitrofurantoína/uso terapéutico , Infecciones Urinarias/genética , Infecciones Urinarias/microbiología , beta-Lactamasas/efectos de los fármacos
6.
Indian J Med Res ; 149(2): 216-221, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-31219086

RESUMEN

Background & objectives: Nosocomial infections caused by multidrug-resistant, Pseudomonas species have become a major clinical and public health concern. The aim of this study was to characterize phenotypic and genotypic profile of antimicrobial resistance (AMR) in Pseudomonas spp. isolated from hospitalized patients. Methods: A total of 126 consecutive, non-duplicate isolates of Pseudomonas spp. isolated from various clinical samples were included in the study over a period of two years. Identification and antimicrobial sensitivity was performed using automated culture system according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. Phenotypic detection of extended-spectrum ß-lactamases (ESBLs), Amp-C ß-lactamase (AmpC) and metallo-ß-lactamases (MBLs) were done by various combinations of disc-diffusion and E-test methods, followed by polymerase chain reaction-based detection of ß-lactamase-encoding genes. Results: Among 126 clinical isolates, 121 (96.1%) isolates were identified as Pseudomonas aeruginosa. Most of the isolates were recovered from pus sample, 35 (27.8%) followed by urine, 25 (19.84%); endotracheal aspirate, 24 (19.04%); blood, 14 (11.11%) and sputum, four (3.17%). The highest rate of resistance was against ticarcillin-clavulanic acid, 113 (89.7%) followed by meropenem, 92 (72.5%) and ceftazidime, 91 (72.3%). Overall, ESBLs, AmpC and carbapenemase production was detected in 109 (96.4%), 64 (50.8%) and 105 (94.6%) isolates by phenotypic methods. The most prevalent ESBL gene was blaTEMin 72 (57.1%) and the least prevalent was blaSHVin 19 (15.1%) isolates. AmpC gene was seen less compared to ESBL gene. The most prevalent carbapenemases gene was blaNDM-141 (46.06%) followed by blaVIM and blaOXA-1. Interpretation & conclusions: Our findings suggested that a high rate of ESBLs and carbapenemases production was observed in Pseudomonas spp. Therefore, phenotypic and genotypic detection of AMR needs to be combined for better characterization of resistance patterns in Pseudomonas spp.


Asunto(s)
Farmacorresistencia Bacteriana/genética , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Infecciones por Pseudomonas/tratamiento farmacológico , Pseudomonas aeruginosa/genética , Adulto , Antibacterianos/efectos adversos , Antibacterianos/uso terapéutico , Proteínas Bacterianas/genética , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Femenino , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Infecciones por Pseudomonas/epidemiología , Infecciones por Pseudomonas/genética , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/patogenicidad , beta-Lactamasas/genética
7.
Indian J Med Res ; 149(2): 276-280, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-31219094

RESUMEN

Background & objectives: Rampant use of ß-lactam antibiotics in both community and hospitals has transformed the human healthy intestinal gut flora into a reservoir of antibiotic-resistant organisms. This study was conducted to find the faecal presence of antibiotic-resistant Enterobacteriaceae in faecal samples in the community in north India. Methods: In this prospective study, 207 stool samples were collected from apparently healthy individuals residing in a semiurban community in Chandigarh, India, from August to October, 2015. Isolates belonging to family Enterobacteriaceae were identified using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), and antibiotic susceptibility was determined using Clinical Laboratory Standard Institute disc diffusion method. Detection of extended spectrum ß-lactamases (TEM, SHV, OXA-1, CTXM 1, CTXM 2, CTXM 9 and CTXM 8/25), carbapenemases (IMP, VIM and KPC) and New Delhi metallo-ß-lactamase was done by multiplex PCR. Results: Of the population studied, 55.5 per cent were females and 60 per cent were illiterate or had only primary education; 43.4 per cent individuals were aged <20 yr. Overall, 70.5 per cent of stool samples had antibiotic-resistant isolates. Maximum resistance was seen for cephalosporins (60.4%) followed by fluoroquinolones (41.5%). The multidrug-resistant (MDR) isolates were 2.4 per cent. The most commonly detected genes were TEM, SHV, OXA-1, CTXM-1, CTXM-2, CTXM-9 and CTXM-8/25 ß-lactamases. Escherichia coli was the most common resistant isolate, and TEM was the most common gene detected. Interpretation & conclusions: Overall, 70.5 per cent members of Enterobacteriaceae had antibiotic resistance in the community and 2.4 per cent were MDR. Higher resistance rates were observed for most commonly used drugs such as cephalosporins and fluoroquinolones. High rate of antibiotic-resistant Enterobacteriaceae in gut of healthy individuals points towards the need for active screening and prevention of dissemination.


Asunto(s)
Farmacorresistencia Bacteriana/genética , Infecciones por Enterobacteriaceae/epidemiología , Enterobacteriaceae/genética , beta-Lactamasas/genética , Adulto , Cefalosporinas/uso terapéutico , Farmacorresistencia Bacteriana/efectos de los fármacos , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/patogenicidad , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Heces/microbiología , Femenino , Microbioma Gastrointestinal/efectos de los fármacos , Humanos , India/epidemiología , Masculino , Persona de Mediana Edad , Pseudomonas aeruginosa/efectos de los fármacos , Pseudomonas aeruginosa/patogenicidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Adulto Joven
8.
Biomed Res Int ; 2019: 2494913, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31205937

RESUMEN

Rhesus macaques (Macaca mulatta) are hosts to a range of zoonotic and potentially zoonotic pathogens. The present study firstly provides a broader investigation of the presence and prevalence of zoonotic fecal pathogens in wild Taihangshan macaques, a subspecies of rhesus macaque in China. A total of 458 fecal samples were collected between September 2015 and November 2016. Fourteen genera of intestinal parasites (four genera of protozoans and ten genera of helminths) and twelve genera of bacteria were tested for using PCR amplification. The overall samples prevalence of parasitic infection was 98.25%. Entamoeba spp. (89.96%), Balantidium coli (70.09%), and Isospora spp. (28.38%) were the most prevalent protozoa, whereas the predominant prevalent helminths were Trichuris sp. (93.23%), Strongyloides spp. (73.36%), and Oesophagostomum sp. (31.66%). Ten genera of intestinal bacteria were detected in samples of rhesus macaques, including Shigella (31.66%), Escherichia coli (29.91%), Klebsiella pneumoniae (28.38%), Leptospira (26.64%), Campylobacter jejuni (18.34%), Salmonella (13.32%), etc. Eight samples (1.75%) were tested Hafnia-positive based on sequences analysis of 16S rRNA and ampC gene. This is the first molecular characterization of Hafnia infection in NHPs. Our cross-sectional prevalence study provides important information for monitoring the potential transmission of zoonotic infections from wild rhesus macaques.


Asunto(s)
Infecciones por Enterobacteriaceae/genética , Heces/microbiología , Hafnia/genética , Enfermedades de los Monos , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Zoonosis , Animales , Macaca mulatta , Enfermedades de los Monos/genética , Enfermedades de los Monos/microbiología , Reacción en Cadena de la Polimerasa , Zoonosis/genética , Zoonosis/microbiología
9.
Infect Immun ; 87(7)2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31061145

RESUMEN

Tissue-resident memory T cells (TRM cells) are a novel population of tissue-restricted antigen-specific T cells. TRM cells are induced by pathogens and promote host defense against secondary infections. Although TRM cells cannot be detected in circulation, they are the major memory CD4+ and CD8+ T-cell population in tissues in mice and humans. Murine models of CD8+ TRM cells have shown that CD8+ TRM cells maintain tissue residency via CD69 and though tumor growth factor ß-dependent induction of CD103. In contrast to CD8+ TRM cells, there are few models of CD4+ TRM cells. Thus, much less is known about the factors regulating the induction, maintenance, and host defense functions of CD4+ TRM cells. Citrobacter rodentium is known to induce IL-17+ and IL-22+ CD4+ T cells (Th17 and Th22 cells, respectively). Moreover, data from IL-22 reporter mice show that most IL-22+ cells in the colon 3 months after C. rodentium infection are CD4+ T cells. This collectively suggests that C. rodentium may induce CD4+ TRM cells. Here, we demonstrate that C. rodentium induces a population of IL-17A+ CD4+ T cells that are tissue restricted and antigen specific, thus meeting the criteria of CD4+ TRM cells. These cells expand and are a major source of IL-22 during secondary C. rodentium infection, even before the T-cell phase of the host response in primary infection. Finally, using FTY 720, which depletes circulating naive and effector T cells but not tissue-restricted T cells, we show that these CD4+ TRM cells can promote host defense.


Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Citrobacter rodentium/inmunología , Infecciones por Enterobacteriaceae/inmunología , Animales , Citrobacter rodentium/genética , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Humanos , Memoria Inmunológica , Interleucina-17/genética , Interleucina-17/inmunología , Interleucinas/genética , Interleucinas/inmunología , Ratones , Ratones Endogámicos C57BL , Células Th17/inmunología
10.
Gene ; 701: 152-160, 2019 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-30910556

RESUMEN

Edwardsiella tarda belongs to the genera of Gram negative bacterium mainly associated with edwardsiellosis, the most commonly found infectious fish disease throughout the globe. E. tarda is also a widespread pathogen which cause infections such as cellulitis or gas gangrene and generalized infections in humans. To control the escalating infection of E. trada on various species, it is essential to decoded the mysterious mechanism behind the bacterial infection at transcript level. In this present study, we carry out a de novo E. tarda Whole transcriptome sequencing, isolated from infected fish intestine using SOLiD sequencing platform. RNA-Seq data analysis was performed using various bioinformatics pipelines. Protein-protein interaction study for pathway enrichment and gene ontology study were executed for further investigation. Assembly statistics for E. tarda dataset showed that the number of transcript contigs was 9657 out of which 6749 were GO annotated whereas 1528 were not assigned any GO terms. GO analysis showed that the expressed genes were enhanced with molecular function, cellular component and biological process. A KEGG enrichment study showed that pathway's that are directly linked with immune diseases like Rheumatoid arthritis (0.2%), Tuberculosis (0.3%) Endocytosis (0.6%) was considerably enriched. Protein-protein interaction study showed that most of the expressed proteins were involved in metabolic pathways, flagellar assembly, Propanoate metabolism, Microbial metabolism in diverse environments, Butanoate metabolism and Carbon. The present study provides novel E. tarda transcriptome sequence data, allowing us to identify biologically significant genes and their functional relationship with fish diseases, and will be useful in recognize the reliable therapeutic targets in near feature.


Asunto(s)
Proteínas Bacterianas , Cipriniformes/microbiología , Edwardsiella tarda , Infecciones por Enterobacteriaceae , Enfermedades de los Peces , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica , Animales , Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/genética , Edwardsiella tarda/genética , Edwardsiella tarda/aislamiento & purificación , Edwardsiella tarda/metabolismo , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/metabolismo , Infecciones por Enterobacteriaceae/veterinaria , Enfermedades de los Peces/genética , Enfermedades de los Peces/metabolismo , Enfermedades de los Peces/microbiología
11.
Int J Antimicrob Agents ; 53(5): 650-656, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30878669

RESUMEN

OBJECTIVES: The objective of this work was to provide detailed molecular data on clinically acquired AmpC (qAmpC)-producing Enterobacteriaceae from two different periods (2002-2008 and 2010-2013) in order to clarify the contribution of clonal and plasmid genetic platforms for the current epidemiological scenario concerning extended-spectrum beta-lactams resistance. METHODS: We analysed 1246 Enterobacteriaceae non-susceptible to third-generation cephalosporins from two hospitals and one community laboratory between 2010 and 2013. Bacterial identification, antibiotic susceptibility, identification of qAmpC and plasmid-mediated quinolone resistance genes, clonal (pulsed-field gel electrophoresis (PFGE), Multilocus sequence typing (MLST)) and plasmid (S1-/I-CeuI-PFGE, replicon typing, hybridization) analysis were performed by standard methods. Whole-genome sequencing (WGS) was performed in two ST11-Klebsiella pneumoniae isolates harbouring DHA-1. RESULTS: The occurrence of qAmpC was lower (2.6%) than that observed in a previous survey (7.4%), and varied slightly over time. Isolates produced DHA-1 (53%), CMY-2 (44%) or DHA-6 (3%), but significant epidemiological changes were observed in the two surveys. While DHA-1 persisted in different institutions by selection of a worldwide epidemic IncR plasmid in an ST11 harbouring KL105, CMY-2 rates increased over time linked to IncI1 plasmids (instead of IncK or IncA/C2) in multiple Escherichia coli clones. CONCLUSIONS: The higher frequency of DHA-1 qAmpC in these species contrasts with the scenario in most European countries. Furthermore, the different genetic backgrounds associated with either extended-spectrum ß-lactamases (ESBLs) or acquired AmpC ß-lactamases (qAmpC) in our country might have contributed to their differential expansion.


Asunto(s)
Proteínas Bacterianas/biosíntesis , Proteínas Bacterianas/genética , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/microbiología , Plásmidos/análisis , beta-Lactamasas/biosíntesis , beta-Lactamasas/genética , Infecciones por Enterobacteriaceae/genética , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Portugal/epidemiología , Prevalencia , Secuenciación Completa del Genoma
12.
PLoS One ; 14(1): e0208505, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30640915

RESUMEN

A prospective cohort study (German Clinical Trial Registry, No. 00005273) was performed to determine pre-admission colonization rates, hospital acquisition risk factors, subsequent infection rates and colonization persistence including the respective molecular epidemiology and transmission rates of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae (EPE). A total of 342 EPEs were isolated from rectal swabs of 1,334 patients on admission, at discharge and 6 months after hospitalization. Inclusion criteria were patients' age > 18 years, expected length of stays > 48 hours, external referral. The EPEs were characterized by routine microbiological methods, a DNA microarray and ERIC-PCR. EPE colonization was found in 12.7 % of admitted patients, with the highest rate (23.8 %) in patients from nursing homes. During hospitalization, 8.1 % of the patients were de novo EPE colonized, and invasive procedures, antibiotic and antacid therapies were independent risk factors. Only 1/169 patients colonized on admission developed a hospital-acquired EPE infection. Escherichia coli was the predominant EPE (88.9 %), and 92.1% of the ESBL phenotypes could be related to CTX-M variants with CTX-M-1/15 group being most frequent (88.9%). A corresponding ß-lactamase could not be identified in five isolates. Hospital-acquired EPE infections in patients colonized before or during hospitalization were rare. The diversity of the EPE strains was much higher than that of the underlying plasmids. In seven patients, transmission of the respective plasmid across different species could be observed indicating that the current strain-based surveillance approaches may underestimate the risk of inter-species transmission of resistance genes.


Asunto(s)
Farmacorresistencia Bacteriana/genética , Genes Bacterianos , Hospitales , beta-Lactamasas/biosíntesis , Recuento de Colonia Microbiana , Enterobacteriaceae/genética , Enterobacteriaceae/crecimiento & desarrollo , Enterobacteriaceae/aislamiento & purificación , Infecciones por Enterobacteriaceae/epidemiología , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Estudios de Seguimiento , Humanos , Epidemiología Molecular , Admisión del Paciente , Alta del Paciente , Plásmidos/genética , Factores de Riesgo , beta-Lactamasas/genética
13.
Genes Immun ; 20(3): 207-213, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-29728609

RESUMEN

Citrobacter rodentium is a murine pathogen causing transmissible colonic hyperplasia and colitis with a pathogenic mechanism similar to foodborne enterohaemorrhagic Escherichia coli in humans. Mechanisms underlying intestinal responses to C. rodentium infection are incompletely understood. We identified 24 colonic microRNAs (miRNAs) as significantly deregulated in response to C. rodentium, including miR-7a, -17, -19a, -20a, -20b, -92a, -106a, -132, -200a, and -2137; most of these miRNAs belong to the oncogenic miR-17-92 clusters. Pathways involved in cell cycle, cancers, and immune responses were enriched among the predicted targets of these miRNAs. We further demonstrated that an apoptosis facilitator, Bim, is a candidate gene target of miRNA-mediated host response to the infection. These findings suggest that host miRNAs participate in C. rodentium pathogenesis and may represent novel treatment targets.


Asunto(s)
Infecciones por Enterobacteriaceae/genética , MicroARNs/genética , Animales , Citrobacter rodentium/patogenicidad , Infecciones por Enterobacteriaceae/inmunología , Infecciones por Enterobacteriaceae/microbiología , Ratones , MicroARNs/metabolismo , Transcriptoma
14.
PLoS One ; 13(12): e0209623, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30576382

RESUMEN

Global dissemination of New Delhi metallo-ß-lactamase (NDM)-producing bacteria has become a major health threat. However, there are few reports regarding the identification and characterisation of NDM-producing bacteria from West Africa, including Ghana. An Escherichia coli strain with resistance to meropenem was isolated from the Tamale Teaching Hospital in Ghana. Its identification and determination of antibiotic susceptibility profile were carried out using commercial systems. The antibiotic resistance mechanism was analysed by phenotypic detection kits, PCR, and DNA sequencing. Conjugation experiments, S1 nuclease pulsed field gel electrophoresis, and Southern blotting were performed. Finally, the NDM-1-harbouring plasmid was characterised using next-generation sequencing and phylogenetic analysis. The meropenem-resistant Escherichia coli strain EC2189 harboured blaNDM-1 and belonged to sequence type 410. blaNDM-1 was located on the IncHI type transferrable plasmid p2189-NDM (248,807 bp long), which co-carried multiple resistance genes, such as blaCTX-M-15, aadA1, aac(6')-Ib, sul3, dfrA12, and cmlA1. p2189-NDM phylogenetically differed from previously identified blaNDM-1-positive IncHI type plasmids. A truncated Tn125 containing blaNDM-1 was bracketed by an ISSm-1-like insertion sequence upstream and by a site-specific integrase downstream. To the best of our knowledge, we have, for the first time identified and molecularly characterised an NDM-1-producing Enterobacteriaceae strain in Ghana with blaNDM-1 that had a novel genetic structure. Our findings indicate a possibility of NDM-1 dissemination in Ghana and underscore the need for constant monitoring of carbapenemase-producing bacteria.


Asunto(s)
Infecciones por Enterobacteriaceae/genética , Escherichia coli/genética , Plásmidos/genética , beta-Lactamasas/genética , Antibacterianos/efectos adversos , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Infecciones por Enterobacteriaceae/microbiología , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Filogenia
15.
Elife ; 72018 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-30543324

RESUMEN

Inflammation often induces regeneration to repair the tissue damage. However, chronic inflammation can transform temporary hyperplasia into a fertile ground for tumorigenesis. Here, we demonstrate that the microRNA miR-34a acts as a central safeguard to protect the inflammatory stem cell niche and reparative regeneration. Although playing little role in regular homeostasis, miR-34a deficiency leads to colon tumorigenesis after Citrobacter rodentium infection. miR-34a targets both immune and epithelial cells to restrain inflammation-induced stem cell proliferation. miR-34a targets Interleukin six receptor (IL-6R) and Interleukin 23 receptor (IL-23R) to suppress T helper 17 (Th17) cell differentiation and expansion, targets chemokine CCL22 to hinder Th17 cell recruitment to the colon epithelium, and targets an orphan receptor Interleukin 17 receptor D (IL-17RD) to inhibit IL-17-induced stem cell proliferation. Our study highlights the importance of microRNAs in protecting the stem cell niche during inflammation despite their lack of function in regular tissue homeostasis.


Asunto(s)
Transformación Celular Neoplásica/genética , Colon/metabolismo , Infecciones por Enterobacteriaceae/genética , Perfilación de la Expresión Génica , Inflamación/genética , MicroARNs/genética , Animales , Células Cultivadas , Citrobacter rodentium/fisiología , Colon/microbiología , Colon/patología , Infecciones por Enterobacteriaceae/microbiología , Inflamación/microbiología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Células Madre Neoplásicas/metabolismo , Receptores de Interleucina/genética , Receptores de Interleucina/metabolismo , Células Th17/metabolismo
16.
Front Immunol ; 9: 2732, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30532756

RESUMEN

HuR is an abundant RNA-binding protein acting as a post-transcriptional regulator of many RNAs including mRNAs encoding inflammatory mediators, cytokines, death signalers and cell cycle regulators. In the context of intestinal pathologies, elevated HuR is considered to enhance the stability and the translation of pro-tumorigenic mRNAs providing the rationale for its pharmacological targeting. However, HuR also possesses specific regulatory functions for innate immunity and cytokine mRNA control which can oppose intestinal inflammation and tumor promotion. Here, we aim to identify contexts of intestinal inflammation where the innate immune and the epithelial functions of HuR converge or diverge. To address this, we use a disease-oriented phenotypic approach using mice lacking HuR either in intestinal epithelia or myeloid-derived immune compartments. These mice were compared for their responses to (a) Chemically induced Colitis; (b) Colitis- associated Cancer (CAC); (c) T-cell mediated enterotoxicity; (d) Citrobacter rodentium-induced colitis; and (e) TNF-driven inflammatory bowel disease. Convergent functions of epithelial and myeloid HuR included their requirement for suppressing inflammation in chemically induced colitis and their redundancies in chronic TNF-driven IBD and microbiota control. In the other contexts however, their functions diversified. Epithelial HuR was required to protect the epithelial barrier from acute inflammatory or infectious degeneration but also to promote tumor growth. In contrast, myeloid HuR was required to suppress the beneficial inflammation for pathogen clearance and tumor suppression. This cellular dichotomy in HuR's functions was validated further in mice engineered to express ubiquitously higher levels of HuR which displayed diminished pathologic and beneficial inflammatory responses, resistance to epithelial damage yet a heightened susceptibility to CAC. Our study demonstrates that epithelial and myeloid HuR affect different cellular dynamics in the intestine that need to be carefully considered for its pharmacological exploitation and points toward potential windows for harnessing HuR functions in intestinal inflammation.


Asunto(s)
Citrobacter rodentium/inmunología , Colitis/inmunología , Proteína 1 Similar a ELAV/inmunología , Infecciones por Enterobacteriaceae/inmunología , Mucosa Intestinal/inmunología , Animales , Colitis/genética , Colitis/microbiología , Colitis/patología , Proteína 1 Similar a ELAV/genética , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Infecciones por Enterobacteriaceae/patología , Inmunidad Innata , Inflamación/genética , Inflamación/inmunología , Inflamación/microbiología , Inflamación/patología , Mucosa Intestinal/microbiología , Mucosa Intestinal/patología , Ratones , Ratones Transgénicos
17.
Nat Commun ; 9(1): 4187, 2018 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-30305622

RESUMEN

Niche-adaptation of a bacterial pathogen hinges on the ability to recognize the complexity of signals from the environment and integrate that information with the regulation of genes critical for infection. Here we report the transcriptome of the attaching and effacing pathogen Citrobacter rodentium during infection of its natural murine host. Pathogen gene expression in vivo was heavily biased towards the virulence factor repertoire and was found to be co-ordinated uniquely in response to the host. Concordantly, we identified the host-specific induction of a metabolic pathway that overlapped with the regulation of virulence. The essential type 3 secretion system and an associated suite of distinct effectors were found to be modulated co-ordinately through a unique mechanism involving metabolism of microbiota-derived 1,2-propanediol, which dictated the ability to colonize the host effectively. This study provides novel insights into how host-specific metabolic adaptation acts as a cue to fine-tune virulence.


Asunto(s)
Sistemas de Secreción Bacterianos , Citrobacter rodentium/metabolismo , Infecciones por Enterobacteriaceae/microbiología , Interacciones Huésped-Patógeno , Animales , Adhesión Bacteriana , Citrobacter rodentium/genética , Citrobacter rodentium/patogenicidad , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/patología , Regulación Bacteriana de la Expresión Génica , Células HeLa , Interacciones Huésped-Patógeno/genética , Humanos , Metabolómica , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Propilenglicol/metabolismo , Análisis de Secuencia de ARN , Transcriptoma/genética , Virulencia/genética , Factores de Virulencia/metabolismo
18.
PLoS Pathog ; 14(8): e1007272, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30169545

RESUMEN

Edwardsiella piscicida is a leading fish pathogen that causes significant economic loses in the aquaculture industry. The pathogen depends on type III and type VI secretion systems (T3/T6SS) for growth and virulence in fish and the expression of both systems is controlled by the EsrB transcription activator. Here, we performed a Tn-seq-based screen to uncover factors that govern esrB expression. Unexpectedly, we discovered that RpoS antagonizes esrB expression and thereby inhibits production of E. piscicida's T3/T6SS. Using in vitro transcription assays, we showed that RpoS can block RpoD-mediated transcription of esrB. ChIP-seq- and RNA-seq-based profiling, as well as mutational and biochemical analyses revealed that RpoS-repressed promoters contain a -6G in their respective discriminator sequences; moreover, this -6G proved critical for RpoS to inhibit esrB expression. Mutation of the RpoS R99 residue, an amino acid that molecular modeling predicts interacts with -6G in the esrB discriminator, abolished RpoS' capacity for repression. In a turbot model, an rpoS deletion mutant was attenuated early but not late in infection, whereas a mutant expressing RpoSR99A exhibited elevated fitness throughout the infection period. Collectively, these findings deepen our understanding of how RpoS can inhibit gene expression and demonstrate the temporal variation in the requirement for this sigma factor during infection.


Asunto(s)
Proteínas Bacterianas/fisiología , Edwardsiella/genética , Edwardsiella/patogenicidad , Enfermedades de los Peces , Regiones Promotoras Genéticas/genética , Factor sigma/fisiología , Virulencia/genética , Animales , Acuicultura , Proteínas Bacterianas/metabolismo , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/microbiología , Enfermedades de los Peces/genética , Enfermedades de los Peces/microbiología , Peces Planos , Regulación Bacteriana de la Expresión Génica , Unión Proteica , Factor sigma/metabolismo
19.
Diagn Microbiol Infect Dis ; 92(1): 1-7, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29983286

RESUMEN

As carbapenemase-producing Enterobacteriaceae (CPE) and extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E) are becoming a major public health issue, there is an urgent need for accurate and fast diagnostic tests. The ELITe InGenius is a fully automated sample-to-result system designed for the extraction and detection by multiplex real-time polymerase chain reaction of carbapenemases KPC, NDM, VIM, IMP, and OXA-48-like variants and CTX-M group 1 and 9-producers from diverse sample matrices such as colonies, positive blood cultures, and rectal swabs. CRE and ESBL ELITe MGB® kits were evaluated on 153 cultured colonies of enterobacterial isolates with characterized ß-lactamase content, on 30 spiked blood cultures, and the CRE kit was also evaluated on 53 clinical rectal swabs collected prospectively during a 3-month period and 10 spiked rectal swabs. CRE ELITe MGB® kit's performances reached 100% sensitivity and 100% specificity, while for the ESBL ELITe kit, 100% sensitivity and 96.6% specificity were observed, with a sample to result of less than 3 h and a total percentage of agreement with expected results of 99.6% (255/256).


Asunto(s)
Proteínas Bacterianas/genética , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Pruebas Diagnósticas de Rutina/métodos , beta-Lactamasas/genética , Técnicas Bacteriológicas/métodos , Infecciones por Enterobacteriaceae/genética , Humanos , Pruebas de Sensibilidad Microbiana/métodos , Estudios Prospectivos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Sensibilidad y Especificidad
20.
Mol Genet Genomics ; 293(6): 1453-1467, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30027301

RESUMEN

For many pathogenic members of the Enterobacterales, siderophores play an important role in virulence, yet the siderophores of the host-associating members of the genus Pantoea remain unexplored. We conducted a genome-wide survey of environmental and host-associating strains of Pantoea to identify known and candidate siderophore biosynthetic clusters. Our analysis identified three clusters homologous to those of enterobactin, desferrioxamine, and aerobactin that were prevalent among Pantoea species. Using both phylogenetic and comparative genomic approaches, we demonstrate that the enterobactin-like cluster was present in the common ancestor of all Pantoea, with evidence for three independent losses of the cluster in P. eucalypti, P. eucrina, and the P. ananatis-P. stewartii lineage. The desferrioxamine biosynthetic cluster, previously described and characterized in Pantoea, was horizontally acquired from its close relative Erwinia, with phylogenetic evidence that these transfer events were ancient and occurred between ancestral lineages. The aerobactin cluster was identified in three host-associating species groups, P. septica, P. ananatis, and P. stewartii, with strong evidence for horizontal acquisition from human-pathogenic members of the Enterobacterales. Our work identifies and describes the key siderophore clusters in Pantoea, shows three distinct evolutionary processes driving their diversification, and provides a foundation for exploring the roles that these siderophores may play in human opportunistic infections.


Asunto(s)
Infecciones por Enterobacteriaceae/genética , Interacción Gen-Ambiente , Interacciones Huésped-Patógeno/genética , Pantoea/genética , Sideróforos/biosíntesis , Sideróforos/genética , Animales , Vías Biosintéticas/genética , Deferoxamina/metabolismo , Infecciones por Enterobacteriaceae/microbiología , Evolución Molecular , Transferencia de Gen Horizontal , Especificidad del Huésped/genética , Humanos , Familia de Multigenes , Filogenia , Virulencia
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