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1.
Nat Commun ; 11(1): 4915, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004811

RESUMO

A phenotype of Escherichia coli and Klebsiella pneumoniae, resistant to piperacillin/tazobactam (TZP) but susceptible to carbapenems and 3rd generation cephalosporins, has emerged. The resistance mechanism associated with this phenotype has been identified as hyperproduction of the ß-lactamase TEM. However, the mechanism of hyperproduction due to gene amplification is not well understood. Here, we report a mechanism of gene amplification due to a translocatable unit (TU) excising from an IS26-flanked pseudo-compound transposon, PTn6762, which harbours blaTEM-1B. The TU re-inserts into the chromosome adjacent to IS26 and forms a tandem array of TUs, which increases the copy number of blaTEM-1B, leading to TEM-1B hyperproduction and TZP resistance. Despite a significant increase in blaTEM-1B copy number, the TZP-resistant isolate does not incur a fitness cost compared to the TZP-susceptible ancestor. This mechanism of amplification of blaTEM-1B is an important consideration when using genomic data to predict susceptibility to TZP.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/tratamento farmacológico , Proteínas de Escherichia coli/genética , Escherichia coli/genética , beta-Lactamases/genética , Antibacterianos/uso terapêutico , Cromossomos Bacterianos/genética , Elementos de DNA Transponíveis/genética , DNA Bacteriano/genética , Quimioterapia Combinada/métodos , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Amplificação de Genes , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano/genética , Humanos , Testes de Sensibilidade Microbiana , Piperacilina/farmacologia , Piperacilina/uso terapêutico , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genética , Tazobactam/farmacologia , Tazobactam/uso terapêutico , Sequenciamento Completo do Genoma
2.
BMC Infect Dis ; 20(1): 741, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33036564

RESUMO

BACKGROUND: Cholera remains a major global health challenge. Uvira, in the Democratic Republic of the Congo (DRC), has had endemic cholera since the 1970's and has been implicated as a possible point of origin for national outbreaks. A previous study among this population, reported a case confirmation rate of 40% by rapid diagnostic test (RDT) among patients at the Uvira Cholera Treatment Centre (CTC). This study considers the prevalence and diversity of 15 enteric pathogens in suspected cholera cases seeking treatment at the Uvira CTC. METHODS: We used the Luminex xTAG® multiplex PCR to test for 15 enteric pathogens, including toxigenic strains of V. cholerae in rectal swabs preserved on Whatman FTA Elute cards. Results were interpreted on MAGPIX® and analyzed on the xTAG® Data Analysis Software. Prevalence of enteric pathogens were calculated and pathogen diversity was modelled with a Poisson regression. RESULTS: Among 269 enrolled CTC patients, PCR detected the presence of toxigenic Vibrio cholerae in 38% (103/269) of the patients, which were considered to be cholera cases. These strains were detected as the sole pathogen in 36% (37/103) of these cases. Almost half (45%) of all study participants carried multiple enteric pathogens (two or more). Enterotoxigenic Escherichia coli (36%) and Cryptosporidium (28%) were the other most common pathogens identified amongst all participants. No pathogen was detected in 16.4% of study participants. Mean number of pathogens was highest amongst boys and girls aged 1-15 years and lowest in women aged 16-81 years. Ninety-three percent of toxigenic V. cholerae strains detected by PCR were found in patients having tested positive for V. cholerae O1 by RDT. CONCLUSIONS: Our study supports previous results from DRC and other cholera endemic areas in sub-Sahara Africa with less than half of CTC admissions positive for cholera by PCR. More research is required to determine the causes of severe acute diarrhea in these low-resource, endemic areas to optimize treatment measures. TRIAL REGISTRATION: This study is part of the impact evaluation study entitled: "Impact Evaluation of Urban Water Supply Improvements on Cholera and Other Diarrheal Diseases in Uvira, Democratic Republic of Congo" registered on 10 October 2016 at clinicaltrials.gov Identification number: NCT02928341 .


Assuntos
Cólera/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium/genética , Diarreia/epidemiologia , Surtos de Doenças , Escherichia coli Enterotoxigênica/genética , Infecções por Escherichia coli/epidemiologia , Vibrio cholerae/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Cólera/microbiologia , Criptosporidiose/parasitologia , República Democrática do Congo/epidemiologia , Testes Diagnósticos de Rotina , Diarreia/microbiologia , Doenças Endêmicas , Infecções por Escherichia coli/microbiologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Prevalência , Microbiologia da Água , Adulto Jovem
3.
Vet Parasitol Reg Stud Reports ; 21: 100435, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32862896

RESUMO

Faecal specimens from 36 scouring neonatal calves from two dairy farms located in the Al Ain region of the UAE were screened with pathogen-specific antigen ELISA for Cryptosporidium parvum, Escherichia coli K99, rotavirus, and coronavirus. Additionally, faecal smears were stained with modified-acid-fast for Cryptosporidium oocysts, and the VITEK 2 system plus Gram's stain used to identify bacteria isolated from the faecal samples. Farm management practices were also evaluated during a farm visit. Of the 36 calves, 29, 13, 5, and 6 were positive for C. parvum, E. coli K99, bovine coronavirus, and rotavirus antigens respectively, while 27 were positive for Cryptosporidium oocysts. In various combinations, mixed infections were detected in 20/36 calves. This is the first report of C. parvum, E. coli K99, Salmonella spp., rotavirus, and coronavirus in ≤14-days-old scouring neonatal dairy calves from the UAE. Molecular characterization of these pathogens and nationwide epidemiological calf scour studies are recommended.


Assuntos
Doenças dos Bovinos/epidemiologia , Criptosporidiose/epidemiologia , Cryptosporidium parvum , Animais , Animais Recém-Nascidos/microbiologia , Animais Recém-Nascidos/parasitologia , Bovinos , Doenças dos Bovinos/microbiologia , Doenças dos Bovinos/parasitologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/veterinária , Coronavirus Bovino , Indústria de Laticínios , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Feminino , Masculino , Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/veterinária , Salmonelose Animal/epidemiologia , Emirados Árabes Unidos/epidemiologia
4.
BMC Infect Dis ; 20(1): 659, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32894092

RESUMO

BACKGROUND: Diarrheagenic Escherichia coli (DEC) are among the leading pathogens associated with endemic diarrhea in low income countries. Yet, few epidemiological studies have focused the contribution of enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli (EIEC) and diffusely adherent E. coli (DAEC). METHODS: We assessed the contribution of EHEC, EIEC and DAEC isolated from stool samples from a case-control study conducted in children aged < 5 years in Southern Mozambique between December 2007 and November 2012. The isolates were screened by conventional PCR targeting stx1 and stx2 (EHEC), ial and ipaH (EIEC), and daaE (DAEC) genes. RESULTS: We analyzed 297 samples from cases with less-severe diarrhea (LSD) matched to 297 controls, and 89 samples from cases with moderate-to-severe diarrhea (MSD) matched to 222 controls, collected between November 3, 2011 and November 2, 2012. DEC were more common among LSD cases (2.7%, [8/297] of cases vs. 1.3% [4/297] of controls; p = 0.243]) than in MSD cases (0%, [0/89] of cases vs. 0.4%, [1/222] of controls; p = 1.000). Detailed analysis revealed low frequency of EHEC, DAEC or EIEC and no association with diarrhea in all age strata. Although the low frequency, EIEC was predominant in LSD cases aged 24-59 months (4.1% for cases vs. 0% for controls), followed by DAEC in similar frequency for cases and controls in infants (1.9%) and lastly EHEC from one control. Analysis of a subset of samples from previous period (December 10, 2007 and October 31, 2011) showed high frequency of DEC in controls compared to MSD cases (16.2%, [25/154] vs. 11.9%, [14/118], p = 0.383, respectively). Among these, DAEC predominated, being detected in 7.7% of cases vs. 17.6% of controls aged 24-59 months, followed by EIEC in 7.7% of cases vs. 5.9% of controls for the same age category, although no association was observed. EHEC was detected in one sample from cases and two from controls. CONCLUSIONS: Our data suggests that although EHEC, DAEC and EIEC are less frequent in endemic diarrhea in rural Mozambique, attention should be given to their transmission dynamics (e.g. the role on sporadic or epidemic diarrhea) considering that the role of asymptomatic individuals as source of dissemination remains unknown.


Assuntos
Diarreia/epidemiologia , Escherichia coli Êntero-Hemorrágica/genética , Infecções por Escherichia coli/epidemiologia , Saúde da População Rural , Estudos de Casos e Controles , Pré-Escolar , Diarreia/microbiologia , Doenças Endêmicas , Escherichia coli Êntero-Hemorrágica/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Moçambique/epidemiologia , Reação em Cadeia da Polimerase , Prevalência , População Rural
5.
PLoS Biol ; 18(9): e3000856, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32941420

RESUMO

Antibiotic combination therapies are important for the efficient treatment of many types of infections, including those caused by antibiotic-resistant pathogens. Combination treatment strategies are typically used under the assumption that synergies are conserved across species and strains, even though recent results show that the combined treatment effect is determined by specific drug-strain interactions that can vary extensively and unpredictably, both between and within bacterial species. To address this problem, we present a new method in which antibiotic synergy is rapidly quantified on a case-by-case basis, allowing for improved combination therapy. The novel CombiANT methodology consists of a 3D-printed agar plate insert that produces defined diffusion landscapes of 3 antibiotics, permitting synergy quantification between all 3 antibiotic pairs with a single test. Automated image analysis yields fractional inhibitory concentration indices (FICis) with high accuracy and precision. A technical validation with 3 major pathogens, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, showed equivalent performance to checkerboard methodology, with the advantage of strongly reduced assay complexity and costs for CombiANT. A synergy screening of 10 antibiotic combinations for 12 E. coli urinary tract infection (UTI) clinical isolates illustrates the need for refined combination treatment strategies. For example, combinations of trimethoprim (TMP) + nitrofurantoin (NIT) and TMP + mecillinam (MEC) showed synergy, but only for certain individual isolates, whereas MEC + NIT combinations showed antagonistic interactions across all tested strains. These data suggest that the CombiANT methodology could allow personalized clinical synergy testing and large-scale screening. We anticipate that CombiANT will greatly facilitate clinical and basic research of antibiotic synergy.


Assuntos
Antibacterianos/administração & dosagem , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Sinergismo Farmacológico , Testes de Sensibilidade Microbiana/métodos , Algoritmos , Andinocilina/administração & dosagem , Andinocilina/farmacologia , Antibacterianos/farmacologia , Quimioterapia Combinada/métodos , Quimioterapia Combinada/normas , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Humanos , Testes de Sensibilidade Microbiana/instrumentação , Nitrofurantoína/administração & dosagem , Nitrofurantoína/farmacologia , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/isolamento & purificação , Reprodutibilidade dos Testes , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Trimetoprima/administração & dosagem , Trimetoprima/farmacologia , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia
6.
Nat Commun ; 11(1): 4035, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32788578

RESUMO

Polyphosphates are linear polymers and ubiquitous metabolites. Bacterial polyphosphates are long chains of hundreds of phosphate units. Here, we report that mouse survival of peritoneal Escherichia coli sepsis is compromised by long-chain polyphosphates, and improves with bacterial polyphosphatekinase deficiency or neutralization using recombinant exopolyphosphatase. Polyphosphate activities are chain-length dependent, impair pathogen clearance, antagonize phagocyte recruitment, diminish phagocytosis and decrease production of iNOS and cytokines. Macrophages bind and internalize polyphosphates, in which their effects are independent of P2Y1 and RAGE receptors. The M1 polarization driven by E. coli derived LPS is misdirected by polyphosphates in favor of an M2 resembling phenotype. Long-chain polyphosphates modulate the expression of more than 1800 LPS/TLR4-regulated genes in macrophages. This interference includes suppression of hundreds of type I interferon-regulated genes due to lower interferon production and responsiveness, blunted STAT1 phosphorylation and reduced MHCII expression. In conclusion, prokaryotic polyphosphates disturb multiple macrophage functions for evading host immunity.


Assuntos
Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Escherichia coli/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata , Polifosfatos/metabolismo , Animais , Apresentação do Antígeno/imunologia , Polaridade Celular , Antígenos de Histocompatibilidade Classe II/metabolismo , Interferon Tipo I/metabolismo , Lipopolissacarídeos , Macrófagos/imunologia , Macrófagos/microbiologia , Camundongos Endogâmicos C57BL , Células Mieloides/imunologia , Fenótipo , Sepse/imunologia , Análise de Sobrevida , Transcriptoma/genética
7.
N Z Med J ; 133(1519): 62-69, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32777796

RESUMO

AIM: To assess whether trimethoprim remains an appropriate empiric treatment for uncomplicated cystitis in women 15-55 years old. METHODS: General practitioners in Auckland, Nelson-Marlborough, Otago and Southland were invited to participate in this audit of current practice. Participating general practitioners were asked to submit urine to the laboratory for microscopy and culture from any woman aged 15-55 years presenting with uncomplicated cystitis. Urine samples submitted as part of the audit were identified by a "copy to" code. Data on laboratory results were extracted from the laboratory information system. RESULTS: Data were collected from June 2016 to August 2018. Four hundred and eighty-one samples were submitted, of which 340 (70.7%) met the inclusion criteria of the audit. A urinary pathogen was identified in 181 (53.2%) specimens, of which 148 (81.8%) were E. coli, 13 (7.2%) other coliforms and 20 (11.0%) Staphylococcus saprophyticus. Of the E. coli isolates, 109 of 148 (73.6%, 95% CI 66.6-80.7) were susceptible to trimethoprim, 144 of 144 (100%, 95% CI 100-100) to nitrofurantoin and 143 of 148 (96.6%, 95% CI 93.7-99.5) to cefalexin. Of the urinary pathogens, 139 of 185 (75.1%, 95% CI 68.9-81.4) were susceptible to trimethoprim, 164 of 177 tested (92.7%, 95% CI 88.8-96.5) to nitrofurantoin and 166 of 178 tested (93.3%, 95% CI 89.6-96.9) to cefalexin. Overall, a uropathogen resistant to trimethoprim was detected in 13.5%, to nitrofurantoin in 3.8%, and to cefalexin in 3.5% of samples tested. CONCLUSION: Similar rates of resistance to trimethoprim were seen in women 15-55 years old presenting with cystitis compared with unselected samples submitted from the general community. Given the high rates of resistance, trimethoprim is no longer appropriate as an empiric treatment option for cystitis in this group. Nitrofurantoin or cefalexin are appropriate alternative empiric treatment options. Given the current recommendation that a urine sample should not be submitted to the laboratory from women with uncomplicated cystitis, ongoing audits will be required to ensure that empiric treatment recommendations remain appropriate.


Assuntos
Antibacterianos/uso terapêutico , Cistite , Farmacorresistência Bacteriana/efeitos dos fármacos , Prescrição Inadequada/estatística & dados numéricos , Trimetoprima/uso terapêutico , Adolescente , Adulto , Antibacterianos/farmacologia , Cistite/tratamento farmacológico , Cistite/microbiologia , Escherichia coli , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Feminino , Clínicos Gerais , Humanos , Auditoria Médica , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Nova Zelândia , Trimetoprima/farmacologia , Adulto Jovem
8.
PLoS One ; 15(8): e0232305, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785271

RESUMO

Shiga toxin-producing Escherichia coli (STEC) that cause severe disease predominantly carry the toxin gene variant stx2a. However, the role of Shiga toxin in the ruminant reservoirs of this zoonotic pathogen is poorly understood and strains that cause severe disease in humans (HUSEC) likely constitute a small and atypical subset of the overall STEC flora. The aim of this study was to investigate the presence of stx2a in samples from cattle and to isolate and characterize stx2a-positive E. coli. In nationwide surveys in Sweden and Norway samples were collected from individual cattle or from cattle herds, respectively. Samples were tested for Shiga toxin genes by real-time PCR and amplicon sequencing and stx2a-positive isolates were whole genome sequenced. Among faecal samples from Sweden, stx1 was detected in 37%, stx2 in 53% and stx2a in 5% and in skin (ear) samples in 64%, 79% and 2% respectively. In Norway, 79% of the herds were positive for stx1, 93% for stx2 and 17% for stx2a. Based on amplicon sequencing the most common stx2 types in samples from Swedish cattle were stx2a and stx2d. Multilocus sequence typing (MLST) of 39 stx2a-positive isolates collected from both countries revealed substantial diversity with 19 different sequence types. Only a few classical LEE-positive strains similar to HUSEC were found among the stx2a-positive isolates, notably a single O121:H19 and an O26:H11. Lineages known to include LEE-negative HUSEC were also recovered including, such as O113:H21 (sequence type ST-223), O130:H11 (ST-297), and O101:H33 (ST-330). We conclude that E. coli encoding stx2a in cattle are ranging from strains similar to HUSEC to unknown STEC variants. Comparison of isolates from human HUS cases to related STEC from the ruminant reservoirs can help identify combinations of virulence attributes necessary to cause HUS, as well as provide a better understanding of the routes of infection for rare and emerging pathogenic STEC.


Assuntos
Bovinos/microbiologia , Toxina Shiga II/genética , Escherichia coli Shiga Toxigênica/genética , Animais , Reservatórios de Doenças/microbiologia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Variação Genética , Genoma Bacteriano , Síndrome Hemolítico-Urêmica/epidemiologia , Síndrome Hemolítico-Urêmica/microbiologia , Humanos , Tipagem de Sequências Multilocus , Noruega/epidemiologia , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Escherichia coli Shiga Toxigênica/citologia , Escherichia coli Shiga Toxigênica/isolamento & purificação , Suécia/epidemiologia , Virulência/genética , Zoonoses/epidemiologia , Zoonoses/microbiologia
9.
PLoS One ; 15(8): e0236703, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785284

RESUMO

Travelers' diarrhea (TD) is the most prevalent illness encountered by deployed military personnel and has a major impact on military operations, from reduced job performance to lost duty days. Frequently, the etiology of TD is unknown and, with underreporting of cases, it is difficult to accurately assess its impact. An increasing number of ailments include an altered or aberrant gut microbiome. To better understand the relationships between long-term deployments and TD, we studied military personnel during two nine-month deployment cycles in 2015-2016 to Honduras. To collect data on the prevalence of diarrhea and impact on duty, a total of 1173 personnel completed questionnaires at the end of their deployment. 56.7% reported reduced performance and 21.1% reported lost duty days. We conducted a passive surveillance study of all cases of diarrhea reporting to the medical unit with 152 total cases and a similar pattern of etiology. Enteroaggregative E. coli (EAEC, 52/152), enterotoxigenic E. coli (ETEC, 50/152), and enteropathogenic E. coli (EPEC, 35/152) were the most prevalent pathogens detected. An active longitudinal surveillance of 67 subjects also identified diarrheagenic E. coli as the primary etiology (7/16 EPEC, 7/16 EAEC, and 6/16 ETEC). Eleven subjects were recruited into a nested longitudinal substudy to examine gut microbiome changes associated with deployment. A 16S rRNA amplicon survey of fecal samples showed differentially abundant baseline taxa for subjects who contracted TD versus those who did not, as well as detection of taxa positively associated with self-reported gastrointestinal distress. Disrupted microbiota was also qualitatively observable for weeks preceding and following the incidents of TD. These findings illustrate the complex etiology of diarrhea amongst military personnel in deployed settings and its impacts on job performance. Potential factors of resistance or susceptibility can provide a foundation for future clinical trials to evaluate prevention and treatment strategies.


Assuntos
Diarreia/epidemiologia , Disenteria/epidemiologia , Escherichia coli Enteropatogênica/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Adulto , Diarreia/genética , Diarreia/microbiologia , Disenteria/genética , Disenteria/microbiologia , Disenteria/patologia , Escherichia coli Enteropatogênica/genética , Escherichia coli Enteropatogênica/patogenicidade , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/genética , Honduras/epidemiologia , Humanos , Masculino , Militares , RNA Ribossômico 16S/genética , Fatores de Risco , Viagem , Doença Relacionada a Viagens
10.
PLoS Pathog ; 16(8): e1008776, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32845938

RESUMO

Enteroaggregative Escherichia coli (EAEC) is a diarrheagenic pathotype associated with traveler's diarrhea, foodborne outbreaks and sporadic diarrhea in industrialized and developing countries. Regulation of virulence in EAEC is mediated by AggR and its negative regulator Aar. Together, they control the expression of at least 210 genes. On the other hand, we observed that about one third of Aar-regulated genes are related to metabolism and transport. In this study we show the AggR/Aar duo controls the metabolism of lipids. Accordingly, we show that AatD, encoded in the AggR-regulated aat operon (aatPABCD) is an N-acyltransferase structurally similar to the essential Apolipoprotein N-acyltransferase Lnt and is required for the acylation of Aap (anti-aggregation protein). Deletion of aatD impairs post-translational modification of Aap and causes its accumulation in the bacterial periplasm. trans-complementation of 042aatD mutant with the AatD homolog of ETEC or with the N-acyltransferase Lnt reestablished translocation of Aap. Site-directed mutagenesis of the E207 residue in the putative acyltransferase catalytic triad disrupted the activity of AatD and caused accumulation of Aap in the periplasm due to reduced translocation of Aap at the bacterial surface. Furthermore, Mass spectroscopy revealed that Aap is acylated in a putative lipobox at the N-terminal of the mature protein, implying that Aap is a lipoprotein. Lastly, deletion of aatD impairs bacterial colonization of the streptomycin-treated mouse model. Our findings unveiled a novel N-acyltransferase family associated with bacterial virulence, and that is tightly regulated by AraC/XylS regulators in the order Enterobacterales.


Assuntos
Acetiltransferases/metabolismo , Fator de Transcrição AraC/metabolismo , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , Escherichia coli/patogenicidade , Regulação Bacteriana da Expressão Gênica , Acetiltransferases/genética , Acilação , Animais , Fator de Transcrição AraC/química , Fator de Transcrição AraC/genética , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Óperon , Filogenia , Conformação Proteica , Virulência
11.
PLoS Pathog ; 16(8): e1008856, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32845936

RESUMO

Copper and superoxide are used by the phagocytes to kill bacteria. Copper is a host effector encountered by uropathogenic Escherichia coli (UPEC) during urinary tract infection in a non-human primate model, and in humans. UPEC is exposed to higher levels of copper in the gut prior to entering the urinary tract. Effects of pre-exposure to copper on bacterial killing by superoxide has not been reported. We hypothesized that copper-replete E. coli is more sensitive to killing by superoxide in vitro, and in activated macrophages. We utilized wild-type UPEC strain CFT073, and its isogenic mutants lacking copper efflux systems, superoxide dismutases (SODs), regulators of a superoxide dismutase, and complemented mutants to address this question. Surprisingly, our results reveal that copper protects UPEC against killing by superoxide in vitro. This copper-dependent protection was amplified in the mutants lacking copper efflux systems. Increased levels of copper and manganese were detected in UPEC exposed to sublethal concentration of copper. Copper activated the transcription of sodA in a SoxR- and SoxS-dependent manner resulting in enhanced levels of SodA activity. Importantly, pre-exposure to copper increased the survival of UPEC within RAW264.7 and bone marrow-derived murine macrophages. Loss of SodA, but not SodB or SodC, in UPEC obliterated copper-dependent protection from superoxide in vitro, and from killing within macrophages. Collectively, our results suggest a model in which sublethal levels of copper trigger the activation of SodA and SodC through independent mechanisms that converge to promote the survival of UPEC from killing by superoxide. A major implication of our findings is that bacteria colonizing copper-rich milieus are primed for efficient detoxification of superoxide.


Assuntos
Cobre/farmacologia , Infecções por Escherichia coli/tratamento farmacológico , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Superóxidos/toxicidade , Infecções Urinárias/tratamento farmacológico , Escherichia coli Uropatogênica/efeitos dos fármacos , Animais , Infecções por Escherichia coli/induzido quimicamente , Infecções por Escherichia coli/microbiologia , Feminino , Regulação Bacteriana da Expressão Gênica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Superóxido Dismutase/genética , Infecções Urinárias/induzido quimicamente , Infecções Urinárias/microbiologia
12.
Medicine (Baltimore) ; 99(28): e21113, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32664134

RESUMO

RATIONALE: Emphysematous osteomyelitis is a rare disease caused by gas-forming bacteria. But only 45 cases have been reported in the literature since then. PATIENT CONCERNS: A 72-year-old female presented to our hospital with severe lower back pain that aggravated 4 days ago. DIAGNOSES: Computed tomography (CT) revealed intraosseous mottled air in the T12 and L1 vertebral bodies and epidural space. The enhanced T1 and T2 magnetic resonance imaging scans showed heterogeneous signal intensity of vertebral bodies, suggestive of emphysematous osteomyelitis. INTERVENTIONS: Surgery was performed to identify culture strains and to remove emphysematous lesions of the vertebral body using extensive transpedicular irrigation. OUTCOMES: Escherichia coli (E coli) was identified in the surgical specimen, and intravenous antibiotic therapy was continued with cefotaxime. The patient had a significant decrease in lower back pain after the surgery and the final CT scan before discharge revealed significantly decreased air at T12 and L1 vertebral bodies and no air density in the epidural space. LESSONS: We present a patient diagnosed with emphysematous osteomyelitis in vertebral bodies caused by E coli and successfully treated with surgical intervention.


Assuntos
Enfisema/diagnóstico , Infecções por Escherichia coli/diagnóstico , Vértebras Lombares , Osteomielite/diagnóstico , Doenças da Coluna Vertebral/diagnóstico , Vértebras Torácicas , Idoso , Enfisema/etiologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/microbiologia , Feminino , Humanos , Imagem por Ressonância Magnética , Osteomielite/complicações , Doenças Raras , Doenças da Coluna Vertebral/complicações , Tomografia Computadorizada por Raios X
13.
BMC Infect Dis ; 20(1): 453, 2020 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-32600258

RESUMO

INTRODUCTION: Uropathogenic E. coli is the leading cause of Urinary tract infections (UTIs), contributing to 80-90% of all community-acquired and 30-50% of all hospital-acquired UTIs. Biofilm forming Uropathogenic E. coli are associated with persistent and chronic inflammation leading to complicated and or recurrent UTIs. Biofilms provide an environment for poor antibiotic penetration and horizontal transfer of virulence genes which favors the development of Multidrug-resistant organisms (MDRO). Understanding biofilm formation and antimicrobial resistance determinants of Uropathogenic E. coli strains will provide insight into the development of treatment options for biofilm-associated UTIs. The aim of this study was to determine the biofilm forming capability, presence of virulence genes and antimicrobial susceptibility pattern of Uropathogenic E. coli isolates in Uganda. METHODS: This was a cross-sectional study carried in the Clinical Microbiology and Molecular biology laboratories at the Department of Medical Microbiology, Makerere University College of Health Sciences. We randomly selected 200 Uropathogenic E. coli clinical isolates among the stored isolates collected between January 2018 and December 2018 that had significant bacteriuria (> 105 CFU). All isolates were subjected to biofilm detection using the Congo Red Agar method and Antimicrobial susceptibility testing was performed using the Kirby disk diffusion method. The isolates were later subjected PCR for the detection of Urovirulence genes namely; Pap, Fim, Sfa, Afa, Hly and Cnf, using commercially designed primers. RESULTS: In this study, 62.5% (125/200) were positive biofilm formers and 78% (156/200) of these were multi-drug resistant (MDR). The isolates were most resistant to Trimethoprim sulphamethoxazole and Amoxicillin (93%) followed by gentamycin (87%) and the least was imipenem (0.5%). Fim was the most prevalent Urovirulence gene (53.5%) followed by Pap (21%), Sfa (13%), Afa (8%), Cnf (5.5%) and Hyl (0%). CONCLUSIONS: We demonstrate a high prevalence of biofilm-forming Uropathogenic E. coli strains that are highly associated with the MDR phenotype. We recommend routine surveillance of antimicrobial resistance and biofilm formation to understand the antibiotics suitable in the management of biofilm-associated UTIs.


Assuntos
Antibacterianos/uso terapêutico , Biofilmes/crescimento & desenvolvimento , Infecções por Escherichia coli/epidemiologia , Infecções Urinárias/epidemiologia , Escherichia coli Uropatogênica/genética , Escherichia coli Uropatogênica/patogenicidade , Estudos Transversais , Farmacorresistência Bacteriana Múltipla/genética , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Fenótipo , Reação em Cadeia da Polimerase , Prevalência , Uganda/epidemiologia , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia , Escherichia coli Uropatogênica/efeitos dos fármacos , Escherichia coli Uropatogênica/isolamento & purificação , Virulência/genética , Fatores de Virulência/genética
14.
Nat Commun ; 11(1): 2803, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32499566

RESUMO

Host-associated reservoirs account for the majority of recurrent and oftentimes recalcitrant infections. Previous studies established that uropathogenic E. coli - the primary cause of urinary tract infections (UTIs) - can adhere to vaginal epithelial cells preceding UTI. Here, we demonstrate that diverse urinary E. coli isolates not only adhere to, but also invade vaginal cells. Intracellular colonization of the vaginal epithelium is detected in acute and chronic murine UTI models indicating the ability of E. coli to reside in the vagina following UTI. Conversely, in a vaginal colonization model, E. coli are detected inside vaginal cells and the urinary tract, indicating that vaginal colonization can seed the bladder. More critically, bacteria are identified inside vaginal cells from clinical samples from women with a history of recurrent UTI. These findings suggest that E. coli can establish a vaginal intracellular reservoir, where it may reside safely from extracellular stressors prior to causing an ascending infection.


Assuntos
Células Epiteliais/microbiologia , Escherichia coli Uropatogênica/patogenicidade , Vagina/microbiologia , Animais , Aderência Bacteriana , Infecções por Escherichia coli/microbiologia , Feminino , Camundongos , Camundongos Endogâmicos C3H , Microscopia de Fluorescência , Fagocitose , Bexiga Urinária/microbiologia , Sistema Urinário/microbiologia , Infecções Urinárias/microbiologia , Vagina/citologia
15.
PLoS One ; 15(6): e0235294, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32598400

RESUMO

Drosophila melanogaster's blood cells (hemocytes) play essential roles in wound healing and are involved in clearing microbial infections. Here, we report the transcriptional changes of larval plasmatocytes after clean injury or infection with the Gram-negative bacterium Escherichia coli or the Gram-positive bacterium Staphylococcus aureus compared to hemocytes recovered from unchallenged larvae via RNA-Sequencing. This study reveals 676 differentially expressed genes (DEGs) in hemocytes from clean injury samples compared to unchallenged samples, and 235 and 184 DEGs in E. coli and S. aureus samples respectively compared to clean injury samples. The clean injury samples showed enriched DEGs for immunity, clotting, cytoskeleton, cell migration, hemocyte differentiation, and indicated a metabolic reprogramming to aerobic glycolysis, a well-defined metabolic adaptation observed in mammalian macrophages. Microbial infections trigger significant transcription of immune genes, with significant differences between the E. coli and S. aureus samples suggesting that hemocytes have the ability to engage various programs upon infection. Collectively, our data bring new insights on Drosophila hemocyte function and open the route to post-genomic functional analysis of the cellular immune response.


Assuntos
Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Infecções por Escherichia coli/complicações , Hemócitos/metabolismo , Sepse/genética , Infecções Estafilocócicas/complicações , Infecção dos Ferimentos/genética , Animais , Drosophila melanogaster/crescimento & desenvolvimento , Drosophila melanogaster/microbiologia , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Feminino , Hemócitos/microbiologia , Incidência , Larva/genética , Larva/microbiologia , Masculino , RNA-Seq/métodos , Sepse/epidemiologia , Sepse/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Infecção dos Ferimentos/epidemiologia , Infecção dos Ferimentos/microbiologia
16.
PLoS One ; 15(6): e0233315, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32484827

RESUMO

Integrons play a major role in the evolution and spread of antimicrobial resistance in human pathogens, including Escherichia coli. This study describes the occurrence of class 1 integrons in human pathogenic E. coli, in three isolate collections involving three periods from the last 100 years (i) the Murray collection (n = 58 bacteria isolated from the 1910s to 1940s); (ii) the E. coli reference (ECOR) collection (n = 37 isolates mainly from the 1980s); and (iii) a recently assembled collection (n = 88 isolates obtained in 2016). High-quality whole genome sequences (WGSs) were available for all isolates. Integrons were detected in the WGSs with the program IntegronFinder and the results compared with three established methods: (i) polymerase chain reaction detection of the integrase gene; (ii) BLAST searching using draft genomes; and (iii) mapping of short reads. No integrons were found in any of the Murray Collection isolates; however, integrons were present in 3% of the isolates from ECOR collection, assembled in the 1980s, and 26% of the isolates from the 2010s. Similarly, antimicrobial resistance determinants were not present in the Murray Collection isolates, whereas they were present in 19% of the ECOR Collection isolates and in 55% of the isolates obtained in during the 2010s.


Assuntos
Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Integrons/genética , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/patogenicidade , Infecções por Escherichia coli/genética , Infecções por Escherichia coli/história , Infecções por Escherichia coli/microbiologia , História do Século XX , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase
17.
PLoS One ; 15(6): e0234438, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32525945

RESUMO

Shiga toxin-producing Escherichia coli (STECs) contamination of produce, as a result of contact with ruminant fecal material, has been associated with serious foodborne illness. Bacteriophages (phages) that infect STECs have primarily been reported to be of cattle origin. However, they likely exist in other environments or in animals that share habitats with cattle, such as goats. To explore the presence and diversity of phages specific to STEC O157 and the top six non-O157 STECs in goat-associated environments, environmental samples consisting of feces (goat and cattle) and soil samples were collected monthly for six months from an organic produce farm. A variety of phages belonging to the Myoviridae, Siphoviridae, and Podoviridae families were isolated from all goat fecal and half of the soil samples. The most commonly isolated phages belonged to Myoviridae and were lytic against STEC O103. The isolated phages had different host ranges, but collectively, showed lytic activity against O157 and the top six non-O157 STEC strains excluding O121. Two non-O157 STECs (O174: H21 and O-antigen-negative: H18) were isolated from soil and cattle feces, respectively. Although prior studies have reported that goats shed STEC into the environment, the findings of the current study suggest that goat feces may also contain lytic STEC-specific phages. The phages of goat origin have the capacity to infect STECs implicated in causing foodborne outbreaks, making them potential candidates for biocontrol pending additional characterization steps. Further work is needed to determine if the addition of goats to the farm environment could potentially reduce the presence of STECs.


Assuntos
Bacteriófagos/isolamento & purificação , Fezes/virologia , Cabras/microbiologia , Escherichia coli Shiga Toxigênica/virologia , Criação de Animais Domésticos/métodos , Animais , Bacteriófagos/genética , California , Bovinos/microbiologia , DNA Viral/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Fazendas , Alimentos Orgânicos/microbiologia , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Microbiologia do Solo
18.
PLoS One ; 15(6): e0233704, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32516308

RESUMO

BACKGROUND: The pathogenic spectrum of bloodstream infections (BSIs) varies across regions. Monitoring the pathogenic profile and antimicrobial resistance is a prerequisite for effective therapy, infection control and for strategies aimed to counter antimicrobial resistance. The pathogenic spectrum of BSIs in blood cultures was analysed, focusing on the resistance patterns of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae, in Aljouf region. METHODS: This descriptive cross-sectional study analysed the culture reports of all non-duplicate blood samples collected from January 1 to December 31, 2019. Antibiograms of A. baumannii, E. coli, and K. pneumoniae were analysed for antibiotic resistance. The frequency and percentages of multi-drug, extensively-drug, pan-drug and carbapenem resistance were calculated. RESULTS: Of the 222 bloodstream infections, 62.2% and 36.4% were caused by gram-negative and gram-positive bacteria, respectively. Most BSIs occurred in patients aged ≥60 years (59.5%). Among the 103 isolates of the studied Gram-negative bacteria (GNB), 47.6%, 38.8%, and 2.9% were multi-drug, extensively drug and pan-drug resistant respectively. 46% of K. pneumoniae isolates were carbapenemase producers. Resistance to gentamycin, 1st-4th generation cephalosporins, and carbapenems was observed for A. baumannii. More than 70% of E. coli isolates were resistant to 3rd- and 4th-generation cephalosporins. Klebsiella pneumoniae presented a resistance rate of >60% to imipenems. CONCLUSIONS: Gram-negative bacteria dominate BSIs, with carbapenem-resistant K. pneumoniae most frequently detected in this region. Resistant GNB infections make it challenging to treat geriatric patients. Regional variations in antimicrobial resistance should be continually monitored.


Assuntos
Antibacterianos/farmacologia , Bacteriemia/microbiologia , Carbapenêmicos/farmacologia , Infecções por Klebsiella/epidemiologia , Klebsiella pneumoniae/isolamento & purificação , Infecções por Acinetobacter/sangue , Infecções por Acinetobacter/tratamento farmacológico , Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/isolamento & purificação , Adulto , Antibacterianos/uso terapêutico , Bacteriemia/sangue , Bacteriemia/tratamento farmacológico , Bacteriemia/epidemiologia , Carbapenêmicos/uso terapêutico , Estudos Transversais , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Feminino , Humanos , Infecções por Klebsiella/sangue , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Arábia Saudita , Adulto Jovem
19.
J Med Microbiol ; 69(5): 685-688, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32375948

RESUMO

Carbapenem resistance in Enterobacteriaceae has become an increasingly worrying threat. So far, no epidemiological data regarding NDM-producing enterobacterial isolates has been available on these strains in West Africa. The aim of this study was to seek for carbapenemase-producing Enterobacteriaceae clinical strains isolated in Bamako Teaching Hospital in Mali. Of 50 strains isolated between May 2016 and September 2016, we found a ST448 E. coli harbouring an IncX3 plasmid with bla NDM-5 embedded in the ΔISAba125-ble MBL structure. This study reports the first description of NDM-5 in Mali isolated in an undescribed ST E. coli in West Africa.


Assuntos
Infecções por Escherichia coli/microbiologia , Escherichia coli/genética , beta-Lactamases/genética , Escherichia coli/classificação , Escherichia coli/isolamento & purificação , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , beta-Lactamases/biossíntese
20.
BMC Infect Dis ; 20(1): 342, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32404129

RESUMO

BACKGROUND: Purulent pericarditis is an infectious disease, frequently caused by gram-positive bacteria, that is rarely observed in healthy individuals, and is often associated with predisposing conditions. CASE PRESENTATION: Here, we present the case of an Escherichia coli post-surgical localized purulent pericarditis complicated by transient constrictive pericarditis and its diagnostic and therapeutic management. CONCLUSIONS: Our case report focuses on the importance of imaging-guided treatment of purulent pericardial diseases, in particular on the emerging role of 18 F-labelled 2-fluoro-2-deoxy-D-glucose Positron Emission Tomography/Computed Tomography in pericardial diseases and on the management of transient constrictive pericarditis, often seen after thoracic surgery.


Assuntos
Abscesso/complicações , Estenose da Valva Aórtica/cirurgia , Infecções por Escherichia coli/complicações , Escherichia coli/isolamento & purificação , Pericardite Constritiva/diagnóstico por imagem , Pericardite Constritiva/microbiologia , Infecções Relacionadas à Prótese/complicações , Abscesso/tratamento farmacológico , Antibacterianos/uso terapêutico , Colchicina/uso terapêutico , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Fluordesoxiglucose F18 , Seguimentos , Supressores da Gota/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Pericardite Constritiva/tratamento farmacológico , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Infecções Relacionadas à Prótese/microbiologia , Resultado do Tratamento
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