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1.
World J Microbiol Biotechnol ; 35(9): 134, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31432266

RESUMO

Shiga toxin-producing Escherichia coli (STEC) are zoonotic pathogens and may induce severe diarrheagenic diseases in humans and other animals. Non-O157 STEC have been emerging as important pathogens causing outbreaks worldwide. Bacterial resistance to antimicrobials has become a global public health problem, which involves different ecological spheres, including animals. This study aimed to characterize the resistance to antimicrobials, plasmids and virulence, as well as the serotypes and phylogenetic groups in E. coli isolated from sheep in Brazil. A total of 57 isolates were obtained and showed different antimicrobial resistance profiles. Nineteen isolates presented acquired antimicrobial resistance genes (ARGs) (blaCTX-M-Gp9, qnrB, qnrS, oqxB, oqxA, tetA, tetB, tetC, sul1 and sul2) and plasmid families (F, FIA, FIB, I1, K, HI1 and ColE-like). The stx1, stx2 and ehxA virulence genes were detected by PCR, being 50 isolates (87.7%) classified as STEC. A great diversity of serotypes was detected, being O176:HNM the most predominant. Phylogenetic group E was the most prevalent, followed by B1, A and B2. To the best of our knowledge, this is the first report in the world of blaCTX-M-Gp9 (O75, O114, O100, O128ac and O176 serogroups), qnrB and oqxB genes in non-O157 STEC in healthy sheep. The results obtained in the present study call attention to the monitoring of antimicrobial-resistant non-O157 STEC harboring acquired ARGs worldwide and indicate a zoonotic risk due to the profile of virulence, resistance and serotype found.


Assuntos
Infecções por Escherichia coli/veterinária , Fezes/microbiologia , Doenças dos Ovinos/microbiologia , Escherichia coli Shiga Toxigênica/isolamento & purificação , Animais , Brasil , Infecções por Escherichia coli/microbiologia , Genes Bacterianos , Variação Genética , Genótipo , Técnicas de Genotipagem , Testes de Sensibilidade Microbiana , Filogenia , Plasmídeos/análise , Reação em Cadeia da Polimerase , Sorogrupo , Ovinos , Escherichia coli Shiga Toxigênica/efeitos dos fármacos , Escherichia coli Shiga Toxigênica/genética , Escherichia coli Shiga Toxigênica/patogenicidade , Fatores de Virulência/genética
2.
BMC Vet Res ; 15(1): 268, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31357996

RESUMO

BACKGROUND: This study investigated changes over time in the epidemiology of extended-spectrum ß-lactamase (ESBL) producing Escherichia coli within a single equine referral hospital in the UK. Faecal samples were collected from hospitalised horses in 2008 and 2017, processed using selective media and standard susceptibility laboratory methods. A novel real-time PCR with high resolution melt analysis was used to distinguish blaCTX-M-1 and blaCTX-M-15 within CTX-M-1 group. RESULTS: In 2008, 457 faecal samples from 103 horses were collected, with ESBL-producing E. coli identified in 131 samples (28.7, 95% CI 24.6-33.1). In 2017, 314 faecal samples were collected from 74 horses with ESBL-producing E. coli identified in 157 samples (50.0, 95% CI 44.5-55.5). There were 135 and 187 non-duplicate ESBL-producing isolates from 2008 and 2017, respectively. In 2008, 12.6% of isolates belonged to CTX-M-1 group, all carrying blaCTX-M-1, whilst in 2017, 94.1% of isolates were CTX-M-1 group positive and of these 39.2 and 60.8% of isolates carried blaCTX-M-1 and blaCTX-M-15, respectively. In addition, the prevalence of doxycycline, gentamicin and 3rd generation cephalosporin resistance increased significantly from 2008 to 2017 while a decreased prevalence of phenotypic resistance to potentiated sulphonamides was observed. CONCLUSIONS: The real-time PCR proved a reliable and high throughput method to distinguish between blaCTX-M-1 and blaCTX-M-15. Furthermore, its use in this study demonstrated the emergence of faecal carriage of CTX-M-15 in hospitalised horses, with an increase in prevalence of ESBL-producing E. coli as well as increased antimicrobial resistance to frequently used antimicrobials.


Assuntos
Infecções por Escherichia coli/veterinária , Fezes/microbiologia , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/microbiologia , beta-Lactamases/metabolismo , Animais , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Cavalos , Hospitais Veterinários/estatística & dados numéricos , Prevalência , Reino Unido/epidemiologia , beta-Lactamases/genética
3.
J Med Microbiol ; 68(7): 1033-1041, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31199225

RESUMO

PURPOSE: Enteropathogens are frequently associated with diarrheal disease. Knowledge of their etiology and epidemiology is essential for the prevention and control of the sickness. This study describes the microbiological and epidemiological features of diarrheal disease in 197 symptomatic and 223 asymptomatic under-five-year-old children from southeastern Brazil, between January 2015 and September 2016. METHODS: Isolation of Escherichia coli, Salmonella, Shigella and Campylobacter was realized by culture. E. coli strains were screened by multiplex PCR, PFGE and O:H serotyping. Antimicrobial susceptibility testing was also performed. RESULTS: Most of the 127 enteropathogens isolated were diarrheagenic E. coli (96.1 %), with predominance of several serotypes of enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAEC). Age, sex, rotavirus vaccination, recent use of antibiotics and previous contact with pets, were factors that revealed no significant effects on the probability of infection by the predominant pathogens. Even so, higher incomes could be related to a lesser chance of testing positive for EPEC. Evidence of possible EAEC clonal spread was detected, as well as genetic similarity among strains from both symptomatic and asymptomatic children. Resistance to antimicrobial agents was more pronounced among EAEC than EPEC. CONCLUSION: The occurrence of genetically similar diarrheagenic E. coli in both groups of children, likewise resistant to these agents, underscores the importance of establishing strategies for the prevention of outbreaks, especially among low-income households.


Assuntos
Diarreia/epidemiologia , Diarreia/microbiologia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/genética , Brasil/epidemiologia , Pré-Escolar , Diarreia/economia , Escherichia coli/classificação , Infecções por Escherichia coli/economia , Fezes/microbiologia , Feminino , Humanos , Renda , Lactente , Masculino
4.
BMC Infect Dis ; 19(1): 488, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31151426

RESUMO

BACKGROUND: There are limited studies focusing on liver abscess with negative microbiological cultures. This study evaluated the clinical and prognostic differences of patients with culture-negative liver abscess (CNLA) compared to those with a positive culture (CPLA) and compared these factors between K. pneumoniae liver abscess (KLA) and E. coli liver abscess (ELA). METHODS: A retrospective study of the patients who admitted with a liver abscess at two tertiary hospitals in Korea from 2012 to 2016 was performed. RESULTS: Among a total of 402 patients with liver abscess, 61.2% had positive cultures. K. pneumoniae (n = 133) was the most common cause, followed by E. coli (n = 74). Patients with CPLA were significantly older (p = 0.02) and more frequently had cholelithiasis or biliary tract disease (p = 0.001) compared to patients with CNLA. In-hospital mortality (p = 0.63) and recurrence (p = 0.77) were no different between the two groups. The length of hospital stay was significantly longer in patients with CPLA (p = 0.03) compared with those with CNLA. Subgroup analysis for patients who received 3rd generation cephalosporins empirically showed that in-hospital mortality (p = 0.18) and recurrence (p = 0.27) were not also significantly different. Cholelithiasis, or biliary tract disease (p = 0.001), liver disease (p = 0.001), malignancy (p = 0.0001), and ESBL production (p = 0.0001) were found more frequently in patients with ELA compared with those with KLA. CONCLUSIONS: The prognosis of the CNLA patients was similar to that of the CPLA patients, although the length of hospital stay was shorter in the CNLA patients. The epidemiologic and clinical characteristics of the ELA patients are somewhat different than those of the KLA patients.


Assuntos
Abscesso Hepático Piogênico/diagnóstico , Abscesso Hepático Piogênico/microbiologia , Adulto , Idoso , Doenças Biliares/diagnóstico , Doenças Biliares/epidemiologia , Doenças Biliares/microbiologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Feminino , Mortalidade Hospitalar , Hospitalização/estatística & dados numéricos , Humanos , Infecções por Klebsiella/diagnóstico , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/isolamento & purificação , Abscesso Hepático Piogênico/epidemiologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Recidiva , República da Coreia/epidemiologia , Estudos Retrospectivos , Centros de Atenção Terciária/estatística & dados numéricos
5.
Vet Res ; 50(1): 48, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221216

RESUMO

Enterotoxigenic Escherichia coli (ETEC) are an important cause of post-weaning diarrhea (PWD) in piglets. The IL-17 cytokine family is well known to play important roles in the host defense against bacterial infections at the mucosa. Previously, we reported the potential role of IL-17A in clearing an ETEC infection in piglets. IL-17C, another member of the IL-17 family, is highly expressed in the intestinal epithelium, however, its role during an ETEC infection is still unclear. In this study, we demonstrate that F4+ ETEC induce IL-17C mRNA and protein expression in intestinal tissues as well as in porcine intestinal epithelial cells (IPEC-J2). This IL-17C production is largely dependent on TLR5 signaling in IPEC-J2 cells. Both F4+ ETEC infection and exogenous IL-17C increased the expression of antimicrobial peptides and tight junction proteins, such as porcine beta-defensin (pBD)-2, claudin-1, claudin-2 and occludin in IPEC-J2 cells. Taken together, our data demonstrate that TLR5-mediated IL-17C expression in intestinal epithelial cells enhances mucosal host defense responses in a unique autocrine/paracrine manner in the intestinal epithelium against ETEC infection.


Assuntos
Escherichia coli Enterotoxigênica/fisiologia , Infecções por Escherichia coli/veterinária , Interleucina-17/genética , Doenças dos Suínos/genética , Receptor 5 Toll-Like/genética , Animais , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Interleucina-17/metabolismo , Mucosa Intestinal/fisiopatologia , Suínos , Doenças dos Suínos/metabolismo , Doenças dos Suínos/microbiologia , Receptor 5 Toll-Like/metabolismo
6.
Braz J Infect Dis ; 23(3): 203-206, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31228460

RESUMO

Global dissemination of mcr-like genes represents a serious threat to public health since it jeopardizes the effectiveness of colistin, an antibiotic used as a last-resort treatment against highly antibiotic-resistant bacteria. In 2017, a mcr-1-positive isolate of Escherichia coli was found in Chile for the first time. Herein we report the genetic features of this strain (UCO-457) by whole-genome sequencing (WGS) and conjugation experiments. The UCO-457 strain belonged to ST4204 and carried a 285 kb IncI2-type plasmid containing the mcr-1 gene. Moreover, this plasmid was transferred by conjugation to an E. coli J53 strain at high frequency. The isolate harbored the cma, iroN, and iss virulence genes and did carry resistance genes to trimethoprim/sulfamethoxazole and fluoroquinolones. Other antibiotic resistance determinants such as ß-lactamases-encoding genes were not detected, making the isolate highly susceptible to these antibiotics. Our results revealed that such susceptible isolates could be acting as platforms to disseminate plasmid-mediated colistin resistance. Based on this evidence, we consider that mcr-like prevalence deserves urgent attention and should be examined not only in highly resistant bacteria but also in susceptible isolates.


Assuntos
Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Antibacterianos/farmacologia , Chile , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Escherichia coli/efeitos dos fármacos , Humanos , Pacientes Ambulatoriais
7.
J Med Microbiol ; 68(6): 837-847, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31084700

RESUMO

INTRODUCTION: The last few years have seen the emergence of multi-drug resistant (MDR) Gram-negative infections, which are associated with high morbidity and mortality. The indiscriminate use of colistin has led to the development of resistance, which can be diagnosed effectively by broth microdilution. Studies from India are limited, and this study was conducted in order to determine the prevalence and risk factors associated with colistin resistance. METHODS: Urine samples from patients admitted with urinary tract infection (UTI), growing MDR Escherichia coli and Klebsiella pneumoniae, were tested for the minimum inhibitory concentration (MIC) of colistin by broth microdilution. Isolates with an MIC >2 µg ml-1 (resistant) were subjected to polymerase chain reaction (PCR) for the mcr1, mcr2 and mgrB genes. A case-control study with 21 cases (resistant) and 42 matched controls (sensitive) was designed to evaluate risk factors and outcomes (recurrent UTI, readmission and hospital stay >2 weeks). RESULTS: Two hundred and fifty MDR isolates (E. coli=142/2319 and K.pneumoniae=108/775) from 216 patients were selected from the 25 046 isolates screened. Twenty-five isolates (20 K.pneumoniae and 5 E. coli) were resistant to colistin, with a prevalence of 3.52  % in E. coli and 18.5  % in K. pneumoniae among the MDR isolates. PCR for the mcr1 and mcr2 genes was negative. Multivariate regression showed that multiple episodes of hospitalization, hospital stay >2 weeks, exposure to >three antibiotic classes and abnormality/surgery of the lower urinary tract were the significant risk factors for colistin resistance. Previous use of colistin and colistin resistance had a significant effect on all outcomes. CONCLUSIONS: K. pneumoniae show six times higher prevalence of colistin resistance than E. coli, and the emergence of resistant organisms has led to an increase in morbidity in infected patients.


Assuntos
Antibacterianos/farmacologia , Colistina/farmacologia , Infecções por Escherichia coli/epidemiologia , Escherichia coli/genética , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/genética , Infecções Urinárias/epidemiologia , Adulto , Proteínas de Bactérias/genética , Estudos de Casos e Controles , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Feminino , Humanos , Índia/epidemiologia , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia , Adulto Jovem
8.
BMC Vet Res ; 15(1): 159, 2019 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-31118039

RESUMO

BACKGROUND: Avian pathogenic Escherichia coli (APEC) is the principle cause of colibacillosis affecting poultry. The main challenge to the poultry industry is antimicrobial resistance and the emergence of multidrug resistant bacteria that threaten the safety of the food chain. Risk factors associated with emergence of antimicrobial resistance among avian pathogenic E. coli were correlated with the inappropriate use of antimicrobials along with inadequate hygienic practices, which encourages the selection pressure of antimicrobial resistant APEC. The aim of this study was to isolate, identify, serogroup and genotype APEC from broilers, assess their antibiotic resistance profile, expressed genes and the associated risk factors. RESULTS: APEC was isolated from the visceral organs of sick chickens with a prevalence of 53.4%. The most prevalent serotypes were O1, O2, O25 and O78, in percentage of 14.8, 12.6, 4.4 and 23.7%, respectively. Virulence Associated Genes; SitA, iss, iucD, iucC, astA, tsh cvi and irp2 were detected in rate of 97.4, 93.3, 75, 74, 71, 46.5, 39 and 34%, respectively and 186 (69.2%) isolates possess > 5-10 genes. The highest resistance was found against sulphamethoxazole-trimethoprim, florfenicol, amoxicillin, doxycycline and spectinomycin in percentage; 95.5, 93.7, 93.3, 92.2 and 92.2%, respectively. Sixty-eight percent of APEC isolates were found to have at least 5 out of 8 antimicrobial resistant genes. The most predominant genes were Int1 97%, tetA 78.4%, bla TEM 72.9%, Sul1 72.4%, Sul2 70.2%. Two risk factors were found to be associated with the presence of multi-drug resistant APEC in broiler chickens, with a P value ≤0.05; the use of ground water as source of drinking water and farms located in proximity to other farms. CONCLUSIONS: This study characterized the VAGs of avian pathogenic E. coli and establish their antimicrobial resistance patterns. The widespread of antimicrobial resistance of APEC isolates and detection of ARGs highlighted the need to monitor the spread of ARGs in poultry farms and the environment in Jordan. Use of ground water and closely located farms were significant risk factors associated with the presence of MDR APEC in broiler chickens in Jordan.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Infecções por Escherichia coli/veterinária , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Doenças das Aves Domésticas/microbiologia , Criação de Animais Domésticos , Animais , Galinhas , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Água Subterrânea/microbiologia , Jordânia/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Fatores de Risco
9.
mSphere ; 4(3)2019 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-31068437

RESUMO

Whole-genome sequencing of trimethoprim-resistant Escherichia coli strains MF2165 and PF9285 from healthy Swiss fattening calves revealed a so far uncharacterized dihydrofolate reductase gene, dfrA35 Functionality and association with trimethoprim resistance were demonstrated by cloning and expressing dfrA35 in E. coli The DfrA35 protein showed the closest amino acid identity (49.4%) to DfrA20 from Pasteurella multocida and to the Dfr determinants DfrG (41.2%), DfrD (40.8%), and DfrK (40.0%) found in Gram-positive bacteria. The dfrA35 gene was integrated within a florfenicol/chloramphenicol-sulfonamide resistance ISCR2 element (floR-ISCR2-dfrA35-sul2) next to a Tn21-like transposon that contained genes with resistance to sulfonamides (sul1), streptomycin (aadA1), gentamicin/tobramycin/kanamycin (aadB), and quaternary ammonium compounds (qacEΔ1). A search of GenBank databases revealed that dfrA35 was present in 26 other E. coli strains from different origins as well as in Acinetobacter IMPORTANCE The presence of dfrA35 associated with ISCR2 in Escherichia coli from animals, as well as its presence in other E. coli strains from different sources and countries and in Acinetobacter, highlights the global spread of this gene and its potential for further dissemination. The genetic link of ISCR2-dfrA35 with other antibiotic and disinfectant resistance genes showed that multidrug-resistant E. coli may be selected and maintained by the use of either one of several antimicrobials.


Assuntos
Antibacterianos/farmacologia , Proteínas de Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Tetra-Hidrofolato Desidrogenase/genética , Resistência a Trimetoprima/genética , Trimetoprima/farmacologia , Fatores Etários , Animais , Bovinos , Escherichia coli/genética , Infecções por Escherichia coli/microbiologia
10.
J Med Microbiol ; 68(6): 940-951, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31107199

RESUMO

PURPOSE: This study aimed to characterize 82 atypical enteropathogenic Escherichia coli (aEPEC) isolates, obtained from patients with diarrhea in Brazil, regarding their adherence patterns on HeLa cells and attaching and effacing (AE) lesion pathways. METHODOLOGY: The adherence and fluorescence-actin staining (FAS) assays were performed using HeLa cells. AE lesion pathways were determined through the detection of tyrosine residue 474 (Y474) phosphorylation in the Tir protein, after its translocation to host cells, and by PCR assays for tir genotyping and detection of Tir-cytoskeleton coupling protein (tccP) genes. RESULTS: Regarding the adherence pattern, determined in the presence of d-mannose, 12 isolates (14.6 %) showed the localized adherence (LA)-like pattern, 3 (3.7  %) the aggregative adherence pattern and 4 (4.9  %) a hybrid LA/diffuse adherence pattern. In addition, 36 (43.9  %) isolates displayed an undefined adherence, and 26 (31.7  %) were non-adherent (NA), while one (1.2 %) caused cell detachment. Among the 26 NA aEPEC isolates, 11 showed a type 1 pilus-dependent adherence in assays performed without d-mannose, while 15 remained NA. Forty-eight (58.5 %) aEPEC were able to trigger F-actin accumulation underneath adherent bacteria (FAS-positive), which is an important feature of AE lesions. The majority (58.3 %) of these used the Tir-Nck pathway, while 39.6  % may use both Tir-Nck and Tir-TccP pathways to induce AE lesions. CONCLUSION: Our results reveal the diversity of strategies used by aEPEC isolates to interact with and damage epithelial host cells, thereby causing diarrheal diseases.


Assuntos
Aderência Bacteriana , Escherichia coli Enteropatogênica/fisiologia , Infecções por Escherichia coli/microbiologia , Interações Hospedeiro-Patógeno , Actinas/metabolismo , Diarreia/microbiologia , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/isolamento & purificação , Células Epiteliais/microbiologia , Proteínas de Escherichia coli/metabolismo , Fímbrias Bacterianas/metabolismo , Genótipo , Células HeLa , Humanos , Fenótipo , Fosforilação , Receptores de Superfície Celular/metabolismo
11.
Vet Res ; 50(1): 40, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31126325

RESUMO

Systemic infections caused by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide and are also potentially threatening to human health. Pathogens must be able to precisely modulate gene expression to facilitate their survival and the successful infection. The Cpx two-component signal transduction system (TCS) regulates surface structure assembly and virulence factors implicated in Gram-negative bacterial pathogenesis. However, the roles of the Cpx TCS in bacterial fitness and pathogenesis during APEC infection are not completely understood. Here, we show that the Cpx TCS response regulator CpxR is critical to the survival and virulence of APEC. Inactivation of cpxR leads to significant defects in the interbacterial competition activity, invasion and survival of APEC in vitro and in vivo. Moreover, activation of CpxR positive regulates the expression of the APEC type VI secretion system 2 (T6SS2). Further investigations revealed that phosphorylated CpxR directly bound to the T6SS2 hcp2B promoter region. Taken together, our results demonstrated that CpxR contributes to the pathogensis of APEC at least through directly regulating the expression and function of T6SS2. This study broadens understanding of the regulatory effect of Cpx TCS, thus elucidating the mechanisms through which Cpx TCS involved in bacterial virulence.


Assuntos
Proteínas de Bactérias/metabolismo , Infecções por Escherichia coli/veterinária , Escherichia coli/patogenicidade , Regulação Bacteriana da Expressão Gênica/fisiologia , Doenças das Aves Domésticas/microbiologia , Animais , Aderência Bacteriana , Proteínas de Bactérias/genética , Patos , Ensaio de Desvio de Mobilidade Eletroforética , Infecções por Escherichia coli/microbiologia , Mutação , Regiões Promotoras Genéticas , Virulência , beta-Galactosidase/metabolismo
12.
Malawi Med J ; 31(1): 12-18, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-31143391

RESUMO

Introduction: In Malawi, EcoSan sludge from ecological sanitation (EcoSan) latrines has been found to contain helminths, Salmonella and E. coli above WHO recommended levels making sludge unsuitable for direct handling and use on food crops. This research investigated survival of pathogens in EcoSan sludge with time after sealing the pit. Method: An observational longitudinal follow-up study was conducted where EcoSan latrines were followed from August 2015 to July 2016 in Blantyre and Chikwawa in Southern Malawi. The study enrolled 51 latrines in total with 35 latrines [13 fossa alterna (FAs) and 22 urine diverting dry latrines (UDDLs)] remaining at the end of study. Samples were collected five times from each latrine and examined for helminths, Salmonella and E. coli in the laboratory. Poisson regression was employed to assess factors that significantly contribute to pathogen die off at p<0.05. Results: Average concentrations of all pathogens investigated reduced over 12-month follow-up period except for Salmonella which increased. A. lumbricoides, increased to 2.3 viable eggs during the second sampling and decreased to 0.4 viable eggs per gram after 12 months of follow-up. Time was the only consistent predictor for concentration of helminths. Type of latrine and location were not significant predictors of helminths concentration (p>0.05). However, Salmonella and E. coli colonies were significantly higher in UDDLs (Blantyre) than FAs (Chikwawa) (p<0.05). Conclusion: Pathogen concentration was highest after recommended six months of storage posing a public health risk to those handling and using it for agriculture purposes. It is therefore recommended that the current guidelines be reviewed to suit Malawi context. A storage period of one year or more is recommended.


Assuntos
Infecções por Escherichia coli/epidemiologia , Helmintíase/epidemiologia , Saúde Pública , Saneamento/métodos , Esgotos/análise , Toaletes/estatística & dados numéricos , Animais , Escherichia coli/fisiologia , Infecções por Escherichia coli/microbiologia , Seguimentos , Helmintíase/parasitologia , Helmintos/fisiologia , Humanos , Estudos Longitudinais , Malaui/epidemiologia
13.
Vet Res ; 50(1): 31, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31046828

RESUMO

Avian pathogenic Escherichia coli (APEC) is a facultative intracellular pathogen, and intracellular persistence in macrophages is essential for APEC extraintestinal dissemination. Until now, there is still no systematic interpretation of APEC intracellular proliferation. Intracellular survival factors, especially involved in pathometabolism, need to be further revealed. Acetate plays critical roles in supporting energy homeostasis and acts as a metabolic signal in the inflammatory response of eukaryotes. In this study, we identified that APEC acs-yjcH-actP operon, encoding acetate assimilation system, presented the host-induced transcription during its proliferation in macrophages. Our result showed that this acetate assimilation system acted as a novel intracellular survival factor to promote APEC replication within macrophages. Furthermore, deletion of acs-yjcH-actP operon in APEC decreased its cytotoxic level to macrophages. qRT-PCR results showed that the production of pro-inflammatory cytokines (IL-1ß, IL-6, IL-8, IL-12ß, and TNF-α) and iNOS in FY26∆acs-yjcH-actP infected macrophages were obviously down-regulated compared to that in wild-type FY26 infected cells. Deletion of actP/yjcH/acs genes attenuated APEC virulence and colonization capability in avian lungs in vivo for colibacillosis infection models. And acetate assimilation system acted as a virulence factor and conferred a fitness advantage during APEC early colonization. Taken together, our research unravelled the metabolic requirement of APEC intracellular survival/replication within macrophages, and acetate metabolic requirement acted as an important strategy of APEC pathometabolism. The intracellular acetate consumption during facultative intracellular bacteria replication within macrophages promoted immunomodulatory disorders, resulting in excessively pro-inflammatory responses of host macrophages.


Assuntos
Acetatos/metabolismo , Doenças das Aves/microbiologia , Infecções por Escherichia coli/veterinária , Escherichia coli/metabolismo , Macrófagos/microbiologia , Animais , Linhagem Celular , Galinhas , Citocinas/metabolismo , Patos/microbiologia , Ensaio de Imunoadsorção Enzimática , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/fisiologia , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Doenças das Aves Domésticas/microbiologia , Reação em Cadeia da Polimerase em Tempo Real
14.
Environ Pollut ; 251: 619-627, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31108295

RESUMO

Antibiotic resistance among gram-negative bacteria is increasingly becoming a problem of global concern. Particularly problematic is the emergence of resistance to last-resort antibiotics such as carbapenems and colistin. The increasing number of reports on the plasmid-mediated colistin resistance gene mcr-1 in isolates worldwide is raising concerns for the future usefulness of this class of antibiotics. Dissemination of mcr-1 is believed to have originated mainly from animal breeding, however, the role of the environment as a transmission source is not yet fully understood. In the current study, 89 extended-spectrum ß-lactamase-producing Escherichia coli isolated from 231 samples from different environmental sources in 12 villages in a rural area of Shandong, China, were screened for mcr-1. 17 (19.1%) mcr-1-positive isolates were found from different environmental sources, aggregated in 6 villages. Plasmids of three different Inc-groups carrying mcr-1 were confirmed, indicating that the widespread geographical distribution of mcr-1 in the local area is due to a number of different plasmids. Additionally, almost a third (29.4%) of the isolates carried virulence factors associated to intestinal pathogenic E. coli. These results illustrate the high complexity of the transmission patterns of mcr-1 among different environmental matrices on a local scale and the potential for the environment to facilitate dissemination and emergence of antibiotic-resistant and virulent strains of bacteria.


Assuntos
Portador Sadio/microbiologia , Microbiologia Ambiental , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Escherichia coli/isolamento & purificação , beta-Lactamases/biossíntese , Animais , Antibacterianos/farmacologia , Portador Sadio/epidemiologia , China , Conjugação Genética , Farmacorresistência Bacteriana/genética , Microbiologia Ambiental/normas , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Infecções por Escherichia coli/epidemiologia , Genes Bacterianos , Humanos , Sequenciamento Completo do Genoma
15.
Res Vet Sci ; 124: 426-432, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31082572

RESUMO

Having sensitive serum biomarkers able to determine the structural changes of the small intestine suffering from bacterial digestive diseases could be a valuable tool particularly in piglets at weaning, when intestinal infections are highly prevalent. We evaluated the usefulness of three inflammatory and gut-wall-integrity biomarkers to assess the degree of intestinal histo-morphological damage in piglets. Piglets were orally challenged with Salmonella Typhimurium or enterotoxigenic Escherichia coli (ETEC) to get a variable range of response according to individual variability. Forty-eight piglets were challenged with Salmonella Typhimurium and seventy-two with enterotoxigenic Escherichia coli K88. Clinical signs and faecal score were recorded. At Days 4 and 8 post-inoculation, blood was sampled, animals euthanised and distal ileum dissected. Morphological measures were obtained from the gut tissue, and serum tumour necrosis factor-alpha (TNF-α), pig major acute-phase protein (Pig-MAP) and intestinal fatty acid-binding protein (I-FABP) were determined. Animals developed mild-to-severe diarrhoea after the challenge. When analysing the complete set of analytical results, a high correlation was found among the three serum biomarkers. The most representative morphological indicator was the villus:crypt ratio (V:C), which showed a strong negative correlation with all three biomarkers. Regression analyses between faecal score and the previous variable showed linear relations. When the range of V:C was analysed, based on the quartile distribution of each serum variable, a marked increase in their concentration was observed with greater villus damage. Summarising, the combination of I-FABP, Pig-MAP and TNF-α may be useful for determining the intestinal injury degree and barrier integrity in recently weaned pigs.


Assuntos
Proteínas da Fase Aguda/metabolismo , Infecções por Escherichia coli/veterinária , Proteínas de Ligação a Ácido Graxo/metabolismo , Salmonelose Animal/fisiopatologia , Doenças dos Suínos/fisiopatologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Biomarcadores/metabolismo , Diarreia/microbiologia , Diarreia/fisiopatologia , Modelos Animais de Doenças , Escherichia coli Enterotoxigênica/fisiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/fisiopatologia , Intestinos/microbiologia , Masculino , Salmonelose Animal/microbiologia , Salmonella typhimurium/fisiologia , Sus scrofa , Suínos , Doenças dos Suínos/microbiologia , Desmame
16.
Adv Clin Exp Med ; 28(7): 919-925, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31066244

RESUMO

BACKGROUND: The relationship of diffusely adherent Escherichia coli (DAEC) with pediatric inflammatory bowel disease (IBD) has not been previously studied. Diffusely adherent E. coli are a common cause of long-lasting childhood diarrhea and we postulated that they may induce inflammation of the intestinal mucosa, contributing to the development of IBD in susceptible children. OBJECTIVES: The aim of the study was to investigate the relationship between DAEC and pediatric IBD, including Crohn's disease (CD) and ulcerative colitis (UC). Diffusely adherent E. coli isolates were also assessed regarding their pathogenicity. MATERIAL AND METHODS: Diffusely adherent E. coli were screened among 130 E. coli strains isolated from intestinal biopsy specimens from 26 children with IBD using polymerase chain reaction (PCR) with primers specific to the pathotype and adherence assays to HEp-2 cells. Diffusely adherent E. coli were further analyzed for their ability to adhere to and invade polarized Caco-2 cells. The immunomodulatory effect of DAEC on the secretion of tumor necrosis factor α (TNF-α) by human monocyte-derived macrophages (MDM) was assessed using an immunoenzymatic assay. RESULTS: Diffusely adherent E. coli were recovered from 18 (69.2%) of the 26 intestinal biopsy specimens from both CD and UC patients. Most DAEC isolates carried AfaE3 adhesin, adhered to and were internalized by Caco-2 cells, and induced secretion of elevated levels of TNF-α. CONCLUSIONS: The study demonstrated the internalization of DAEC by intestinal epithelial cells and their ability to induce secretion of increased level of TNF-α in a Caco-2/macrophage compartmentalized culture. This indicated that the pathovar should be considered a pathobiont inducing inflammation of the intestinal mucosa in pediatric patients with IBD.


Assuntos
Aderência Bacteriana , Moléculas de Adesão Celular/metabolismo , Colite Ulcerativa/microbiologia , Doença de Crohn/microbiologia , Infecções por Escherichia coli/epidemiologia , Escherichia coli/isolamento & purificação , Doenças Inflamatórias Intestinais/microbiologia , Mucosa Intestinal/microbiologia , Adesinas de Escherichia coli , Células CACO-2 , Moléculas de Adesão Celular/genética , Criança , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/imunologia , Doença de Crohn/epidemiologia , Doença de Crohn/imunologia , Escherichia coli/genética , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Humanos , Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/imunologia , Mucosa Intestinal/imunologia , Polônia/epidemiologia , Prevalência
17.
Emerg Microbes Infect ; 8(1): 734-748, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31130074

RESUMO

Many pathogens infect hosts through various immune evasion strategies. However, the molecular mechanisms by which pathogen proteins modulate and evade the host immune response remain unclear. Enterohemorrhagic Escherichia coli (EHEC) is a pathological strain that can induce mitogen-activated protein (MAP) kinase (Erk, Jnk and p38 MAPK) and NF-κB pathway activation and proinflammatory cytokine production, which then causes diarrheal diseases such as hemorrhagic colitis and hemolytic uremic syndrome. Transforming growth factor ß-activated kinase-1 (TAK1) is a key regulator involved in distinct innate immune signalling pathways. Here we report that EHEC translocated intimin receptor (Tir) protein inhibits the expression of EHEC-induced proinflammatory cytokines by interacting with the host tyrosine phosphatase SHP-1, which is dependent on the phosphorylation of immunoreceptor tyrosine-based inhibition motifs (ITIMs). Mechanistically, the association of EHEC Tir with SHP-1 facilitated the recruitment of SHP-1 to TAK1 and inhibited TAK1 phosphorylation, which then negatively regulated K63-linked polyubiquitination of TAK1 and downstream signal transduction. Taken together, these results suggest that EHEC Tir negatively regulates proinflammatory responses by inhibiting the activation of TAK1, which is essential for immune evasion and could be a potential target for the treatment of bacterial infection.


Assuntos
Escherichia coli Êntero-Hemorrágica/patogenicidade , Infecções por Escherichia coli/fisiopatologia , Proteínas de Escherichia coli/metabolismo , Interações Hospedeiro-Patógeno , Evasão da Resposta Imune , MAP Quinase Quinase Quinases/antagonistas & inibidores , Receptores de Superfície Celular/metabolismo , Fatores de Virulência/metabolismo , Animais , Infecções por Escherichia coli/microbiologia , Células HEK293 , Humanos , Macrófagos Peritoneais , Camundongos , Camundongos Endogâmicos C57BL , Ligação Proteica , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Células RAW 264.7
18.
Int J Food Microbiol ; 304: 1-10, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31146052

RESUMO

Water contamination by pathogenic bacteria is a global public health problem. Contamination of surface water utilized to irrigate food products, or for human consumption, causes outbreaks of foodborne and waterborne disease. Of these, those caused by diarrheagenic Escherichia coli (DEC) strains present substantial morbidity and mortality. The aim of this study was, therefore, to investigate the microbiological quality of surface water and the presence of DEC strains in different water bodies. A total of 472 water samples were collected from irrigation canal, dam, river, and dike water bodies from January through December 2015 in Sinaloa, a State located in Northwestern Mexico. Our studies demonstrated that 47.0% (222/472) of samples contained thermotolerant coliforms above permissive levels whereas E. coli strains were isolated from 43.6% (206/472). Among these E. coli isolates, DEC strains were identified in 14% (29/206) of samples including in irrigation canal (26/29) and river water (3/29) collected from the northern (83%) and central area (17%). Isolated DEC strains were classified as enteroaggregative E. coli (EAEC) 34.4% (10/29), enteropathogenic E. coli (EPEC) 31.0% (9/29), diffuse adherent E. coli (DAEC) 27.5% (8/29), and enterotoxigenic E. coli (ETEC) 6.8% (2/29). Moreover, 90% of isolated DEC strains exhibited resistance to at least one commonly prescribed antibiotic in Mexico whereas 17% were multi-drug resistant. In conclusion, the presence of DEC strains in surface water represents a potential source for human infection, and thus routine monitoring of DEC in surface water and other indirect affected areas should be considered at northwestern Mexico.


Assuntos
Irrigação Agrícola/métodos , Escherichia coli Enteropatogênica/isolamento & purificação , Escherichia coli Enterotoxigênica/isolamento & purificação , Rios/microbiologia , Qualidade da Água , Antibacterianos/farmacologia , Diarreia/microbiologia , Farmacorresistência Bacteriana Múltipla , Escherichia coli Enteropatogênica/efeitos dos fármacos , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Doenças Transmitidas por Alimentos/microbiologia , Humanos , México/epidemiologia , Água , Microbiologia da Água , Doenças Transmitidas pela Água/microbiologia
19.
MBio ; 10(2)2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015329

RESUMO

Escherichia coli is a major cause of bloodstream and urinary tract infections globally. The wide dissemination of multidrug-resistant (MDR) strains of extraintestinal pathogenic E. coli (ExPEC) poses a rapidly increasing public health burden due to narrowed treatment options and increased risk of failure to clear an infection. Here, we present a detailed population genomic analysis of the ExPEC ST131 clone, in which we seek explanations for its success as an emerging pathogenic strain beyond the acquisition of antimicrobial resistance (AMR) genes. We show evidence for evolution toward separate ecological niches for the main clades of ST131 and differential evolution of anaerobic metabolism, key colonization, and virulence factors. We further demonstrate that negative frequency-dependent selection acting across accessory loci is a major mechanism that has shaped the population evolution of this pathogen.IMPORTANCE Infections with multidrug-resistant (MDR) strains of Escherichia coli are a significant global public health concern. To combat these pathogens, we need a deeper understanding of how they evolved from their background populations. By understanding the processes that underpin their emergence, we can design new strategies to limit evolution of new clones and combat existing clones. By combining population genomics with modelling approaches, we show that dominant MDR clones of E. coli are under the influence of negative frequency-dependent selection, preventing them from rising to fixation in a population. Furthermore, we show that this selection acts on genes involved in anaerobic metabolism, suggesting that this key trait, and the ability to colonize human intestinal tracts, is a key step in the evolution of MDR clones of E. coli.


Assuntos
Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/microbiologia , Evolução Molecular , Escherichia coli Extraintestinal Patogênica/patogenicidade , Variação Genética , Seleção Genética , Fatores de Virulência/metabolismo , Escherichia coli Extraintestinal Patogênica/efeitos dos fármacos , Escherichia coli Extraintestinal Patogênica/genética , Genótipo , Humanos , Fatores de Virulência/genética
20.
J Microbiol Biotechnol ; 29(3): 465-472, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30939632

RESUMO

Several reports describe antimicrobial-resistance transfer among children and the community in outbreak situations, but transfer between a child and a caregiver has not been examined in child care facilities under normal circumstances. We investigated the transfer of antimicrobialresistance genes, resistant bacteria, or both among healthy children and teachers. From 2007 to 2009, 104 Escherichia coli isolates were obtained from four teachers and 38 children in a child care center. Twenty-six cephem-resistant isolates were obtained from children in 2007 and 2008. In 2009, cephem-resistant isolates were detected in children as well as a teacher. Nalidixic acid-resistant isolates from the same teacher for 3 years showed low similarity (<50%) to each other. However, an isolate from a teacher in 2007 and another from a child in 2008 showed high similarity (87%). Pulsed-field gel electrophoresis revealed 100% similarity for four isolates in 2007 and one isolate in 2008, and also similarity among seven isolates carrying the virulence gene (CNF1). This study yielded the following findings: (1) a gene for extended-spectrum ß-lactamase was transferred from a child to other children and a teacher; (2) a nalidixic acid-resistant isolate was transferred from a teacher to a child; and (3) a virulent bacterium was transferred between children.


Assuntos
Cuidado da Criança , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Transferência Genética Horizontal , Antibacterianos/farmacologia , Toxinas Bacterianas/genética , Pré-Escolar , Eletroforese em Gel de Campo Pulsado/métodos , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Fezes/microbiologia , Humanos , Lactente , Testes de Sensibilidade Microbiana , Mutação , Reação em Cadeia da Polimerase/métodos , Quinolonas/farmacologia , República da Coreia , Virulência/genética , beta-Lactamases/genética
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