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1.
Mikrobiyol Bul ; 54(1): 26-39, 2020 Jan.
Artículo en Turco | MEDLINE | ID: mdl-32050876

RESUMEN

Enterococci, which are commonly found in the environment, cause serious infections despite the absence of well-defined virulence factors and toxins. Knowing the virulence properties of enterococci is important to understand the complex pathogenic structures. In this study, we aimed to investigate the virulence factors (asa1, hyl, cylA, efa, ebp, ace, esp, gelE, sprE, fsrA, fsrB, fsrC genes, gelatinase activity, hemolysin, hydrogen peroxide and biofilm production) and antibiotic resistance of Enterococcus faecium and Enterococcus faecalis strains isolated from clinical specimens. A total of 110 enterococcus isolates which were accepted as infectious agents were included in the study. The polymerase chain reaction method was used to identify the isolates and to detect virulence genes. Characteristics of hemolysis, biofilm formation, hydrogen peroxide production and gelatinase activity were investigated by phenotypic methods. The antibiotic susceptibility test was performed with VITEK 2 automated system. E.faecalis ATCC 29212 standard strain was used as a quality control in all tests. Of the 110 enterococci isolates included in the study, 61 were identified as E.faecium and 49 as E.faecalis. The efa gene was the most frequently detected virulence gene (92.7%), followed by ace (83.6%), esp (66.4%), ebp (60.0%), cylA (50.9%), hyl (46.4%), asa1 (45.5%), gelE, sprE, fsrC (33.6%), fsrA (12.7%) and fsrB (11.8%). All genes except hyl were higher in E.faecalis isolates and the difference was statistically significant (p<0.05). Twenty-five (51%) E.faecalis and 1 (1.6%) E.faecium isolates had beta-hemolysis and the difference was statistically significant (p= 0.000). Seven (11.5%) E.faecium and 4 (8.2%) E.faecalis isolates formed biofilm, but the difference was not statistically significant (p> 0.05). Two (3.3%) E.faecium and 14 (28.6%) E.faecalis isolates exhibited gelatinase activity and the difference between the two species was statistically significant (p= 0.000). Hydrogen peroxide production was not detected in any of the isolates. The highest resistance rate was determined against ciprofloxacin (70.9%). The resistance to ampicillin was 69.1%, high level streptomycin 65.1%, high level gentamicin 39.4%, vancomycin and teicoplanin 4.5%, and linezolid 1.8%. In conclusion, our data indicated that virulence factors except hyl gene and biofilm production were higher in E.faecalis isolates but E.faecium isolates were more resistant to antibiotics. In order to prevent infection of such virulent or resistant isolates in the hospital setting, infection control measures must be followed. In vivo studies are needed for the better understanding of the virulence of enterococci.


Asunto(s)
Enterococcus faecalis , Enterococcus faecium , Infecciones por Bacterias Grampositivas , Factores de Virulencia , Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Enterococcus faecalis/efectos de los fármacos , Enterococcus faecalis/genética , Enterococcus faecalis/patogenicidad , Enterococcus faecium/efectos de los fármacos , Enterococcus faecium/genética , Enterococcus faecium/patogenicidad , Infecciones por Bacterias Grampositivas/microbiología , Humanos , Pruebas de Sensibilidad Microbiana , Factores de Virulencia/genética
2.
Gene ; 723: 144134, 2020 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-31589960

RESUMEN

Viral kinases are known to undergo autophosphorylation and also phosphorylate viral and host substrates. Viral kinases have been implicated in various diseases and are also known to acquire host kinases for mimicking cellular functions and exhibit virulence. Although substantial analyses have been reported in the literature on diversity of viral kinases, there is a gap in the understanding of sequence and structural similarity among kinases from different classes of viruses. In this study, we performed a comprehensive analysis of protein kinases encoded in viral genomes. Homology search methods have been used to identify kinases from 104,282 viral genomic datasets. Serine/threonine and tyrosine kinases are identified only in 390 viral genomes. Out of seven viral classes that are based on nature of genetic material, only viruses having double-stranded DNA and single-stranded RNA retroviruses are found to encode kinases. The 716 identified protein kinases are classified into 63 subfamilies based on their sequence similarity within each cluster, and sequence signatures have been identified for each subfamily. 11 clusters are well represented with at least 10 members in each of these clusters. Kinases from dsDNA viruses, Phycodnaviridae which infect green algae and Herpesvirales that infect vertebrates including human, form a major group. From our analysis, it has been observed that the protein kinases in viruses belonging to same taxonomic lineages form discrete clusters and the kinases encoded in alphaherpesvirus form host-specific clusters. A comprehensive sequence and structure-based analysis enabled us to identify the conserved residues or motifs in kinase catalytic domain regions across all viral kinases. Conserved sequence regions that are specific to a particular viral kinase cluster and the kinases that show close similarity to eukaryotic kinases were identified by using sequence and three-dimensional structural regions of eukaryotic kinases as reference. The regions specific to each viral kinase cluster can be used as signatures in the future in classifying uncharacterized viral kinases. We note that kinases from giant viruses Marseilleviridae have close similarity to viral oncogenes in the functional regions and in putative substrate binding regions indicating their possible role in cancer.


Asunto(s)
Proteínas Quinasas/química , Proteínas Quinasas/genética , Virus/clasificación , Dominio Catalítico , Biología Computacional/métodos , Bases de Datos de Proteínas , Variación Genética , Fosforilación , Filogenia , Proteínas Quinasas/metabolismo , Homología de Secuencia de Aminoácido , Proteínas Virales/química , Proteínas Virales/genética , Proteínas Virales/metabolismo , Factores de Virulencia/química , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Virus/enzimología , Virus/patogenicidad
3.
Food Microbiol ; 85: 103280, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31500706

RESUMEN

Listeria monocytogenes causes severe diseases in humans, including febrile gastroenteritis and systemic infections that has a high mortality despite antibiotic treatment. This pathogen may cause massive outbreaks associated to the consumption of contaminated food products, which highlight its importance in public health. In the last decade, L. monocytogenes has emerged as a foodborne pathogen of major importance in Chile. A previous work showed that in Chile during 2008 and 2009, L. monocytogenes serotypes 1/2a, 1/2b and 4b were the most frequently identified in food and clinical strains. Here we report the molecular characterization of L. monocytogenes strains isolated from 2008 to 2017 in the country. Our results indicate that serotypes 1/2a, 1/2b and 4b continue to be the most commonly found in food products. In addition, we identify persistent and widespread PFGE subtypes. This study reports ten years of epidemiological surveillance ofL. monocytogenes in Chile.


Asunto(s)
Monitoreo Epidemiológico , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Listeria monocytogenes/genética , Listeriosis/epidemiología , Chile/epidemiología , Recuento de Colonia Microbiana , ADN Bacteriano/genética , Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos/microbiología , Gastroenteritis/epidemiología , Gastroenteritis/microbiología , Variación Genética , Humanos , Listeria monocytogenes/patogenicidad , Productos de la Carne/microbiología , Epidemiología Molecular , Salud Pública , Serogrupo , Serotipificación , Factores de Virulencia/genética
4.
Food Microbiol ; 86: 103356, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31703863

RESUMEN

Quorum sensing (QS), bacterial cell-to-cell communication, is a gene regulatory mechanism that regulates virulence potential and biofilm formation in many pathogens. Aeromonas sobria, a common aquaculture pathogen, was isolated and identified by our laboratory from the deteriorated turbot, and its potential for virulence factors and biofilm production was regulated by QS system. In view of the interference with QS system, this study was aimed to investigate the effect of methyl anthranilate at sub-Minimum Inhibitory Concentrations (sub-MICs) on QS-regulated phenotypes in A. sobria. The results suggested that 0.5 µL/mL of methyl anthranilate evidently reduced biofilm formation (51.44%), swinging motility (74.86%), swarming motility (71.63%), protease activity (43.08%), and acyl-homoserine lactone (AHL) production. Furthermore, the real-time quantitative PCR (RT-qPCR) and in silico analysis showed that methyl anthranilate might inhibit QS system in A. sobria by interfering with the biosynthesis of AHL, as well as competitively binding with receptor protein. Therefore, our data indicated the feasibility of methyl anthranilate as a promising QS inhibitor and anti-biofilm agent for improving food safety.


Asunto(s)
Aeromonas/efectos de los fármacos , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Percepción de Quorum/efectos de los fármacos , ortoaminobenzoatos/farmacología , 4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , Aeromonas/genética , Aeromonas/fisiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Factores de Virulencia/genética , Factores de Virulencia/metabolismo
5.
Food Microbiol ; 86: 103352, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31703865

RESUMEN

Shiga toxin-producing Escherichia (E.) coli (STEC) pathogens are responsible for the outbreaks of serious diseases in humans, including haemolytic uraemic syndrome (HUS), bloody diarrhoea (BD) and diarrhoea (D), and they pose a significant public health concern. Wild ruminants are an important environmental reservoir of foodborne pathogens that can cause serious illnesses in humans and contaminate fresh products. There is a general scarcity of published data about wildlife as a reservoir of foodborne pathogens in Poland, which is why the potential epidemiological risk associated with red deer, roe deer and fallow deer as reservoirs of STEC/AE-STEC strains was evaluated in this study. The aim of the study was to investigate the prevalence of STEC strains in red deer (Cervus elaphus), roe deer (Capreolus capreolus) and fallow deer (Dama dama) populations in north-eastern Poland, and to evaluate the potential health risk associated with wild ruminants carrying STEC/AE-STEC strains. We examined 252 rectal swabs obtained from 134 roe deer (Capreolus capreolus), 97 red deer (Cervus elaphus) and 21 fallow deer (Dama dama) in north-eastern Poland. The samples were enriched in modified buffered peptone water. Polymerase chain reaction (PCR) assays were conducted to determine the virulence profile of stx1, stx2 and eae or aggR genes, to identify the subtypes of stx1 and stx2 genes, and to perform O and H serotyping. E. coli O157:H7 isolates were detected in the rectal swabs collected from 1/134 roe deer (0.75%) and 4/97 red deer (4.1%), and they were not detected in fallow deer (Dama dama). The remaining E. coli serogroups, namely O26, O103, O111 and O145 that belong to the "top five" non-O157 serogroups, were detected in 15/134 roe deer (11.19%), 18/97 red deer (18.56%) and 2/21 fallow deer (9.52%). STEC/AE-STEC strains were detected in 33 roe deer isolates (24.63%), 21 red deer isolates (21.65%) and 2 fallow deer isolates (9.52%). According to the most recent FAO/WHO report, stx2a and eae genes are the primary virulence traits associated with HUS, and these genes were identified in one roe deer isolate and one red deer isolate. Stx2 was the predominant stx gene, and it was detected in 78.79% of roe deer and in 71.43% of red deer isolates. The results of this study confirmed that red deer and roe deer in north-eastern Poland are carriers of STEC/AE-STEC strains that are potentially pathogenic for humans. This is the first report documenting the virulence of STEC/AE-STEC strains from wild ruminants in Poland.


Asunto(s)
Ciervos/microbiología , Reservorios de Enfermedades/microbiología , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Animales , Animales Salvajes/clasificación , Animales Salvajes/microbiología , Ciervos/clasificación , Reservorios de Enfermedades/clasificación , Polonia , Toxina Shiga/metabolismo , Escherichia coli Shiga-Toxigénica/clasificación , Escherichia coli Shiga-Toxigénica/genética , Escherichia coli Shiga-Toxigénica/metabolismo , Factores de Virulencia/genética , Factores de Virulencia/metabolismo
6.
Food Microbiol ; 86: 103303, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31703885

RESUMEN

Escherichia coli O157:H7 and Salmonella enterica are foodborne pathogens with major public health concern in the U.S. These pathogens utilize several virulence factors to initiate infections in humans. The antimicrobial effect of seven glucosinolate hydrolysis compounds against Salmonella and E. coli O157:H7 was investigated by the disc diffusion assay. Among the tested compounds, benzyl isothiocyanate (BIT), which exerted the highest antimicrobial activity, was evaluated for its anti-virulence properties against these pathogens. The effect of BIT on motility of Salmonella and E. coli O157:H7 and Shiga toxin production by E. coli O157:H7 was determined by the motility assay and ELISA procedure, respectively. Confocal and transmission electron microscopy (TEM) procedures were used to determine bacterial damage at the cellular level. Results revealed that sub-inhibitory concentrations (SICs) of BIT significantly inhibited the motility of both bacteria (P < 0.05). Shiga toxin production by E. coli O157:H7 was decreased by ~32% in the presence of BIT at SICs. TEM results showed the disruption of outer membrane, release of cytoplasmic contents, and cell lysis following BIT treatment. Results suggest that BIT could be potentially used to attenuate Salmonella and E. coli O157:H7 infections by reducing the virulence factors including bacterial motility and Shiga toxin production.


Asunto(s)
Antibacterianos/farmacología , Escherichia coli O157/efectos de los fármacos , Isotiocianatos/farmacología , Salmonella enterica/efectos de los fármacos , Factores de Virulencia/metabolismo , Escherichia coli O157/citología , Escherichia coli O157/genética , Escherichia coli O157/metabolismo , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Salmonella enterica/citología , Salmonella enterica/genética , Salmonella enterica/metabolismo , Toxina Shiga/metabolismo , Factores de Virulencia/antagonistas & inhibidores , Factores de Virulencia/genética
7.
Pol J Microbiol ; 68(4): 493-504, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31880893

RESUMEN

Bird fecal matter is considered a potential source of pathogenic microbes such as yeast species that contaminate the environment. Therefore, it needs to be scrutinized to assess potential environmental health risks. The aim of this study was to investigate the diversity of the yeasts in pigeon fecal droppings, their antifungal susceptibility patterns, and virulence factors. We used culturing techniques to detect the yeasts in pigeon fecal droppings. The isolates were then characterized based on colony morphologies, microscopic examinations, and biochemical reactions. The molecular identification of all yeast isolates was performed by sequencing of the amplified ITS gene. Genes encoding virulence factors CAP1, CAP59, and PLB were also detected. Antifungal susceptibility patterns were examined by the disk diffusion method. A total of 46 yeast-like isolates were recovered, and they belonged to nine different genera, namely, Cryptococcus, Saccharomyces, Rhodotorula, Candida, Meyerozyma, Cyberlindnera, Rhodosporidium, Millerozyma, and Lodderomyces. The prevalence of two genera Cryptococcus and Rhodotorula was high. None of the yeast isolates exhibited any resistance to the antifungal drugs tested; however, all pathogenic Cryptococcus species were positive for virulence determinants like urease activity, growth at 37°C, melanin production, the PLB and CAP genes. This is the first report on the molecular diversity of yeast species, particularly, Cryptococcus species and their virulence attributes in pigeon fecal droppings in Saudi Arabia.Bird fecal matter is considered a potential source of pathogenic microbes such as yeast species that contaminate the environment. Therefore, it needs to be scrutinized to assess potential environmental health risks. The aim of this study was to investigate the diversity of the yeasts in pigeon fecal droppings, their antifungal susceptibility patterns, and virulence factors. We used culturing techniques to detect the yeasts in pigeon fecal droppings. The isolates were then characterized based on colony morphologies, microscopic examinations, and biochemical reactions. The molecular identification of all yeast isolates was performed by sequencing of the amplified ITS gene. Genes encoding virulence factors CAP1, CAP59, and PLB were also detected. Antifungal susceptibility patterns were examined by the disk diffusion method. A total of 46 yeast-like isolates were recovered, and they belonged to nine different genera, namely, Cryptococcus, Saccharomyces, Rhodotorula, Candida, Meyerozyma, Cyberlindnera, Rhodosporidium, Millerozyma, and Lodderomyces. The prevalence of two genera Cryptococcus and Rhodotorula was high. None of the yeast isolates exhibited any resistance to the antifungal drugs tested; however, all pathogenic Cryptococcus species were positive for virulence determinants like urease activity, growth at 37°C, melanin production, the PLB and CAP genes. This is the first report on the molecular diversity of yeast species, particularly, Cryptococcus species and their virulence attributes in pigeon fecal droppings in Saudi Arabia.


Asunto(s)
Columbidae/microbiología , Heces/microbiología , Factores de Virulencia/metabolismo , Levaduras/efectos de los fármacos , Levaduras/aislamiento & purificación , Animales , Antifúngicos/farmacología , Biodiversidad , Fluconazol/farmacología , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Pruebas de Sensibilidad Microbiana , Arabia Saudita , Factores de Virulencia/genética , Levaduras/genética , Levaduras/metabolismo
8.
Pol J Microbiol ; 68(4): 541-548, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31880897

RESUMEN

Analysis of the epidemiology of Staphylococcus aureus (SA) ocular infections and virulence factors of the isolates with a special emphasis on their drug resistance, and the ability of biofilm formation. In a period from 2009 to 2013, 83 isolates of SA were prospectively collected and preserved in a multicenter laboratory-based study carried out in southern Poland. Epidemiological, phenotypic, and genotypic analyses were performed. The resistance and virulence genes were analyzed. Screening for the biofilm formation was provided. Among the materials derived from ocular infections from 456 patients, SA was found in 18.2% (n = 83) of cases (one SA isolate per one patient). Most infections were identified in the age group of over 65 years (OR 8.4 95%CI; 1.03-68.49). The majority of patients (73.4%) were hospitalized. Among the virulence and resistance genes, the most frequently detected were the lukE (72.2%, n = 60) and ermA (15.6%, n = 13) genes. A positive result of the CRA test (the ability of biofilm formation) was found in 66.2% (n = 55) of isolates. Among the strains under study, 6.0% (n = 5) had the methicillin-resistant Staphylococcus aureus phenotype, and 26.5% (n = 22) had the macrolide-lincosamide-streptogramin B phenotype. In 48 (57.8%) isolates the neomycin resistance was revealed. All isolates under study were sensitive to vancomycin. The population most susceptible to ocular SA infections consists of hospitalized patients aged 65 and more. The SA strains under study showed the increased ability to biofilm formation. In the strains tested, high susceptibility to chloramphenicol and fluoroquinolones was demonstrated. However, the high level of drug resistance to neomycin detected in this study among SA isolates and the blood-ocular barrier makes it difficult to treat ocular infections.Analysis of the epidemiology of Staphylococcus aureus (SA) ocular infections and virulence factors of the isolates with a special emphasis on their drug resistance, and the ability of biofilm formation. In a period from 2009 to 2013, 83 isolates of SA were prospectively collected and preserved in a multicenter laboratory-based study carried out in southern Poland. Epidemiological, phenotypic, and genotypic analyses were performed. The resistance and virulence genes were analyzed. Screening for the biofilm formation was provided. Among the materials derived from ocular infections from 456 patients, SA was found in 18.2% (n = 83) of cases (one SA isolate per one patient). Most infections were identified in the age group of over 65 years (OR 8.4 95%CI; 1.03-68.49). The majority of patients (73.4%) were hospitalized. Among the virulence and resistance genes, the most frequently detected were the lukE (72.2%, n = 60) and ermA (15.6%, n = 13) genes. A positive result of the CRA test (the ability of biofilm formation) was found in 66.2% (n = 55) of isolates. Among the strains under study, 6.0% (n = 5) had the methicillin-resistant Staphylococcus aureus phenotype, and 26.5% (n = 22) had the macrolide-lincosamide-streptogramin B phenotype. In 48 (57.8%) isolates the neomycin resistance was revealed. All isolates under study were sensitive to vancomycin. The population most susceptible to ocular SA infections consists of hospitalized patients aged 65 and more. The SA strains under study showed the increased ability to biofilm formation. In the strains tested, high susceptibility to chloramphenicol and fluoroquinolones was demonstrated. However, the high level of drug resistance to neomycin detected in this study among SA isolates and the blood-ocular barrier makes it difficult to treat ocular infections.


Asunto(s)
Proteínas Bacterianas/genética , Farmacorresistencia Bacteriana , Infecciones del Ojo/microbiología , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/genética , Factores de Virulencia/genética , Adolescente , Adulto , Anciano , Antibacterianos/farmacología , Proteínas Bacterianas/metabolismo , Niño , Infecciones del Ojo/epidemiología , Femenino , Humanos , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Polonia/epidemiología , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus/clasificación , Staphylococcus aureus/metabolismo , Factores de Virulencia/metabolismo , Adulto Joven
9.
Pol J Microbiol ; 68(3): 353-369, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31880881

RESUMEN

Listeria monocytogenes is the etiological factor of listeriosis. The main source of these organisms is food, including dairy products. The aim was to determine the multiple correlations between the drug susceptibility, virulence genes (VGs), and biofilm formation on silicone teat cups of milk-borne and human L. monocytogenes strains. The spread of L. monocytogenes via contaminated teat rubbers was assessed. The L. monocytogenes strains recovered from milk (18), human blood (10), and the reference strain ATCC®19111™ were used in the study. Penicillin resistance was the most prevalent resistance in the milk isolates (n=8; 44.4%), whereas among clinical strains erythromycin resistance was predominating - (n=6; 60%). The most frequent VGs among strains isolated from milk were hlyA (100%) and plcB (100%) whereas in strains isolated from blood - hlyA (100%) and prfA (90%). All tested VGs were present in 50% of blood isolates and 11% of milk-borne strains. The strains isolated from milk formed a significantly stronger biofilm. The strains with more numerous virulence genes were resistant to more antibiotics and formed a stronger biofilm. It was shown that contaminated teat cups might contribute to the transmission of L. monocytogenes in the herd. It seems reasonable to monitor the occurrence of L. monocytogenes biofilm in a dairy processing environment.Listeria monocytogenes is the etiological factor of listeriosis. The main source of these organisms is food, including dairy products. The aim was to determine the multiple correlations between the drug susceptibility, virulence genes (VGs), and biofilm formation on silicone teat cups of milk-borne and human L. monocytogenes strains. The spread of L. monocytogenes via contaminated teat rubbers was assessed. The L. monocytogenes strains recovered from milk (18), human blood (10), and the reference strain ATCC®19111™ were used in the study. Penicillin resistance was the most prevalent resistance in the milk isolates (n=8; 44.4%), whereas among clinical strains erythromycin resistance was predominating ­ (n=6; 60%). The most frequent VGs among strains isolated from milk were hlyA (100%) and plcB (100%) whereas in strains isolated from blood ­ hlyA (100%) and prfA (90%). All tested VGs were present in 50% of blood isolates and 11% of milk-borne strains. The strains isolated from milk formed a significantly stronger biofilm. The strains with more numerous virulence genes were resistant to more antibiotics and formed a stronger biofilm. It was shown that contaminated teat cups might contribute to the transmission of L. monocytogenes in the herd. It seems reasonable to monitor the occurrence of L. monocytogenes biofilm in a dairy processing environment.


Asunto(s)
Sangre/microbiología , Listeria monocytogenes/aislamiento & purificación , Listeriosis/microbiología , Leche/microbiología , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Biopelículas , Bovinos , Humanos , Listeria monocytogenes/clasificación , Listeria monocytogenes/genética , Listeria monocytogenes/fisiología , Listeriosis/transmisión , Filogenia , Factores de Virulencia/genética , Factores de Virulencia/metabolismo
10.
Yi Chuan ; 41(12): 1138-1147, 2019 Dec 20.
Artículo en Chino | MEDLINE | ID: mdl-31857285

RESUMEN

Pathogenic Escherichia coli (E. coli) is the most common pathogen causing urinary tract infection in animals. We investigated the antibiotic resistance and virulence genes of pathogenic E. coli CCHTP derived from urine with occult blood of the giant panda by whole genome sequencing. The flanking sequencing of resistance and virulence genes in genomic islands were also analyzed. Our results demonstrate that E. coli CCHTP contains different families of antibiotic resistance genes, most of which are efflux pump related genes, including multiple drug resistance efflux pump genes mdfA, emrE, and mdtN. A total of 166 virulence factors and 563 virulence genes were identified, and the most virulence factors and related genes are involved in host cell attachment and invasion processes. Furthermore, sequence analysis of 19 genomic islands revealed that antibiotic and virulence genes are associated with mobile genetic elements (transposon and insertion sequence) in GIs011 and GIs017. These structures can mediate horizontal transfer of antibiotic and virulence genes. Our work described the distribution of antibiotic resistance genes and virulence genes in E. coli CCHTP, which may provide an important guidance for treatment and rational drug use of E. coli CCHTP infection in the giant panda.


Asunto(s)
Farmacorresistencia Bacteriana , Proteínas de Escherichia coli , Escherichia coli , Orina , Ursidae , Animales , Farmacorresistencia Bacteriana/genética , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Genoma Bacteriano , Orina/microbiología , Ursidae/microbiología , Virulencia/genética , Factores de Virulencia/genética , Secuenciación Completa del Genoma
11.
World J Microbiol Biotechnol ; 35(12): 191, 2019 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-31768723

RESUMEN

Serratia marcescens is an opportunistic human pathogen causing nosocomial infections and displays expanded resistance towards the conventional antibiotics. In S. marcescens, quorum sensing (QS) mechanism coordinates the population-dependent behaviors and regulates the virulence factors production. Photodynamic inactivation (PDI) is a promising alternative for the treatment of infections caused by drug resistant bacteria. Although PDI should be applied at lethal doses, it is possible that during PDI treatment, pathogens encounter sub-lethal doses of PDI (sPDI). sPDI cannot kill microorganisms, but it can considerably influence the microbial virulence. So, in this study, the effect of methylene blue (MB)-mediated PDI on QS-mediated virulence factor production and biofilm formation of S. marcescens at lethal and sub-lethal doses was evaluated. The biofilm formation and virulence factor production of S. marcescens ATCC 13,880 and S. marcescens Sm2 were assessed before and after PDI treatment. Besides, the effect of lethal and sub-lethal PDI on expression of bsmA and bsmB (Biofilm maturation), fimA and fimC (Major fimbrial protein), flhD (Regulator of flagellar mediated swarming and swimming motility) and swrR (AHL-dependent regulator) genes were evaluated by quantitative real time polymerase chain reaction. Lethal and sub-lethal PDI resulted in a significant decrease in biofilm formation, swimming/swarming motility, and pigment and hemolysin production ability of S. marcescens strains. bsmA, bsmB, flhD and swrR genes were down-regulated after PDI treatments. In conclusion, QS-mediated virulence factor production and biofilm formation ability of the two studied S. marcescens strains decreased after both lethal and sub-lethal PDI.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Fotoquimioterapia/métodos , Percepción de Quorum/efectos de la radiación , Serratia marcescens/efectos de la radiación , Factores de Virulencia/metabolismo , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Relación Dosis-Respuesta a Droga , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos/genética , Proteínas Hemolisinas/metabolismo , Azul de Metileno/metabolismo , Microscopía Electrónica de Rastreo , Prodigiosina/metabolismo , Serratia marcescens/genética , Serratia marcescens/metabolismo , Factores de Virulencia/genética
12.
BMC Infect Dis ; 19(1): 928, 2019 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-31684890

RESUMEN

BACKGROUND: Endemic presence of Klebsiella pneumoniae resistant to carbapenem in Italy has been due principally to the clonal expansion of CC258 isolates; however, recent studies suggest an ongoing epidemiological change in this geographical area. METHODS: 50 K. pneumoniae strains, 25 carbapenem-resistant (CR-Kp) and 25 susceptible (CS-Kp), collected from march 2014 to march 2016 at the Laboratory of Bacteriology of the Paolo Giaccone Polyclinic University hospital of Palermo, Italy, were characterized for antibiotic susceptibility and fully sequenced by next generation sequencing (NGS) for the in silico analysis of resistome, virulome, multi-locus sequence typing (MLST) and core single nucleotide polymorphism (SNP) genotypes RESULTS: MLST in silico analysis of CR-Kp showed that 52% of isolates belonged to CC258, followed by ST395 (12%), ST307 (12%), ST392 (8%), ST348 (8%), ST405 (4%) and ST101 (4%). In the CS-Kp group, the most represented isolate was ST405 (20%), followed by ST392 and ST15 (12%), ST395, ST307 and ST1727 (8%). The in silico ß-lactamase analysis of the CR-Kp group showed that the most detected gene was blaSHV (100%), followed by blaTEM (92%), blaKPC (88%), blaOXA (88%) and blaCTX-M (32%). The virulome analysis detected mrk operon in all studied isolates, and wzi-2 was found in three CR-Kp isolates (12%). Furthermore, the distribution of virulence genes encoding for the yersiniabactin system, its receptor fyuA and the aerobactin system did not show significant distribution differences between CR-Kp and CS-Kp, whereas the Klebsiella ferrous iron uptake system (kfuA, kfuB and kfuC genes), the two-component system kvgAS and the microcin E495 were significantly (p < 0.05) prevalent in the CS-Kp group compared to the CR-Kp group. Core SNP genotyping, correlating with the MLST data, allowed greater strain tracking and discrimination than MLST analysis. CONCLUSIONS: Our data support the idea that an epidemiological change is ongoing in the Palermo area (Sicily, Italy). In addition, our analysis revealed the co-existence of antibiotic resistance and virulence factors in CR-Kp isolates; this characteristic should be considered for future genomic surveillance studies.


Asunto(s)
Farmacorresistencia Bacteriana/genética , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/genética , Factores de Virulencia/genética , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Técnicas de Tipificación Bacteriana , Carbapenémicos/farmacología , Farmacorresistencia Bacteriana/efectos de los fármacos , Genotipo , Humanos , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae/clasificación , Klebsiella pneumoniae/aislamiento & purificación , Persona de Mediana Edad , Tipificación de Secuencias Multilocus , Filogenia , Polimorfismo de Nucleótido Simple , Sicilia , beta-Lactamasas/genética
13.
J Agric Food Chem ; 67(48): 13195-13211, 2019 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-31702908

RESUMEN

The increase in the incidence of antibiotic-resistant Staphylococcus aureus (S. aureus) associated infections necessitates the urgent development of novel therapeutic strategies and antibacterial drugs. Antivirulence strategy is an especially compelling alternative strategy due to its low selective pressure for the development of drug resistance in bacteria. Plants and microorganisms are not only important food and medicinal resources but also serve as sources for the discovery of natural products that target bacterial virulence factors. This review discusses the mechanisms of the major virulence factors of S. aureus, including the accessory gene regulator quorum-sensing system, bacterial biofilm formation, α-hemolysin, sortase A, and staphyloxanthin. We also provide an overview of natural products isolated from plants and microorganisms with activity against the major virulence factors of S. aureus and their adjuvant effects on existing antibiotics to overcome antibiotic-resistant S. aureus. Finally, the limitations and solutions of these antivirulence compounds are discussed, which will help in the development of novel antibacterial drugs against antibiotic-resistant S. aureus.


Asunto(s)
Antibacterianos/farmacología , Proteínas Bacterianas/antagonistas & inhibidores , Productos Biológicos/farmacología , Farmacorresistencia Bacteriana , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Factores de Virulencia/antagonistas & inhibidores , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Humanos , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Factores de Virulencia/genética , Factores de Virulencia/metabolismo
14.
Mol Plant Microbe Interact ; 32(12): 1577-1580, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31618137

RESUMEN

The Xanthomonas genus, comprises more than 30 species of gram-negative bacteria, most of which are pathogens of plants with high economic value, such as rice, common bean, and maize. Transcription activator-like effectors (TALEs), which act by regulating the host gene expression, are some of the major virulence factors of these bacteria. We present a novel tool to identify TALE genes in the genome of Xanthomonas strains and their respective targets. The analysis of the results obtained by TargeTALE in a proof-of-concept validation demonstrate that, at optimum setting, approximately 93% of the predicted target genes with available expression data were confirmed as upregulated during the infection, indicating that the tool might be useful for researchers in the field.


Asunto(s)
Genoma Bacteriano , Efectores Tipo Activadores de la Transcripción , Xanthomonas , Proteínas Bacterianas/genética , Interacciones Huésped-Patógeno/genética , Oryza/microbiología , Efectores Tipo Activadores de la Transcripción/genética , Factores de Virulencia/genética , Xanthomonas/genética
15.
Infect Immun ; 88(1)2019 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-31636136

RESUMEN

Streptococcus equi subsp. zooepidemicus is an important pathogen in horses that causes severe diseases such as pneumonia and abortion. Furthermore, it is a zoonotic agent, and contact with horses is a known risk factor. In this study, we investigated the working hypothesis that the zoonotic potential varies among S. equi subsp. zooepidemicus strains in association with differences in M-like protein-mediated binding of host plasma proteins. We demonstrate via in-frame deletion mutagenesis of two different S. equi subsp. zooepidemicus strains that the M-like protein SzM is crucial for the binding of fibrinogen to the bacterial surface and for survival in equine and human blood. S. equi subsp. zooepidemicus isolates of equine and human origins were compared with regard to SzM sequences and binding of equine and human fibrinogens. The N-terminal 216 amino acids of the mature SzM were found to exhibit a high degree of diversity, but the majority of human isolates grouped in three distinct SzM clusters. Plasma protein absorption assays and flow cytometry analysis revealed that pronounced binding of human fibrinogen is a common phenotype of human S. equi subsp. zooepidemicus isolates but much less so in equine S. equi subsp. zooepidemicus isolates. Furthermore, binding of human fibrinogen is associated with specific SzM types. These results suggest that SzM-mediated binding of human fibrinogen is an important virulence mechanism of zoonotic S. equi subsp. zooepidemicus isolates.


Asunto(s)
Antígenos Bacterianos/metabolismo , Proteínas de la Membrana Bacteriana Externa/metabolismo , Proteínas Portadoras/metabolismo , Fibrinógeno/metabolismo , Interacciones Huésped-Patógeno , Streptococcus equi/metabolismo , Factores de Virulencia/metabolismo , Animales , Antígenos Bacterianos/clasificación , Antígenos Bacterianos/genética , Proteínas de la Membrana Bacteriana Externa/clasificación , Proteínas de la Membrana Bacteriana Externa/genética , Proteínas Portadoras/clasificación , Proteínas Portadoras/genética , Análisis por Conglomerados , Variación Genética , Caballos , Humanos , Fenotipo , Unión Proteica , Homología de Secuencia , Factores de Virulencia/clasificación , Factores de Virulencia/genética
16.
Infect Immun ; 88(1)2019 12 17.
Artículo en Inglés | MEDLINE | ID: mdl-31636137

RESUMEN

Mycobacterium tuberculosis Rv3775 (LipE) was annotated as a putative lipase. However, its lipase activity has never been characterized, and its precise role in tuberculosis (TB) pathogenesis has not been thoroughly studied to date. We overexpressed and purified the recombinant LipE (rLipE) protein and demonstrated that LipE has a lipase/esterase activity. rLipE prefers medium-chain ester substrates, with the maximal activity on hexanoate. Its activity is the highest at 40°C and pH 9. We determined that rLipE hydrolyzes trioctanoate. Using site-directed mutagenesis, we confirmed that the predicted putative activity triad residues Ser97, Gly342, and His363 are essential for the lipase activity of rLipE. The expression of the lipE gene was induced under stressed conditions mimicking M. tuberculosis' intracellular niche. The gene-disrupting mutation of lipE led to significantly reduced bacterial growth inside THP-1 cells and human peripheral blood mononuclear cell-derived macrophages and attenuated M. tuberculosis infection in mice (with ∼8-fold bacterial load reduction in mouse lungs). Our data suggest that LipE functions as a lipase and is important for M. tuberculosis intracellular growth and in vivo infection.


Asunto(s)
Esterasas/metabolismo , Lipasa/metabolismo , Mycobacterium tuberculosis/enzimología , Mycobacterium tuberculosis/crecimiento & desarrollo , Tuberculosis/microbiología , Factores de Virulencia/metabolismo , Animales , Análisis Mutacional de ADN , Modelos Animales de Enfermedad , Estabilidad de Enzimas , Esterasas/deficiencia , Esterasas/genética , Humanos , Concentración de Iones de Hidrógeno , Cinética , Lipasa/deficiencia , Lipasa/genética , Ratones , Modelos Teóricos , Mutagénesis Sitio-Dirigida , Células THP-1 , Temperatura Ambiental , Factores de Virulencia/genética
17.
BMC Infect Dis ; 19(1): 873, 2019 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-31640587

RESUMEN

BACKGROUND: There have been no reports regarding the molecular characteristics, virulence features, and antibiotic resistance profiles of Staphylococcus aureus (S. aureus) from Hainan, the southernmost province of China. METHODS: Two hundred twenty-seven S. aureus isolates, consisting of 76 methicillin-resistant S. aureus (MRSA) and 151 methicillin-susceptible S. aureus (MSSA), were collected in 2013-2014 and 2018-2019 in Hainan, and investigated for their molecular characteristics, virulence genes, antibiotic resistance profiles and main antibiotic resistance genes. RESULTS: Forty sequence types (STs) including three new STs (ST5489, ST5492 and ST5493), and 79 Staphylococcal protein A (spa) types were identified based on multilocus sequence typing (MLST) and spa typing, respectively. ST398 (14.1%, 32/227) was found to be the most prevalent, and the prevalence of ST398-MSSA increased significantly from 2013 to 2014 (5.5%, 5/91) to 2018-2019 (18.4%, 25/136). Seventy-six MRSA isolates were subject to staphylococcus chromosomal cassette mec (SCCmec) typing. SCCmec-IVa was the predominant SCCmec type, and specifically, ST45-SCCmec IVa, an infrequent type in mainland China, was predominant in S. aureus from Hainan. The antibiotic resistance profiles and antibiotic resistance genes of S. aureus show distinctive features in Hainan. The resistant rates of the MRSA isolates to a variety of antibiotics were significantly higher than those of the MSSA isolates. The predominant erythromycin and tetracycline resistance genes were ermC (90.1%, 100/111) and tetK (91.8%, 78/85), respectively. Eleven virulence genes, including the Panton-Valentine leukocidin (pvl) and eta, were determined, and the frequency of eta and pvl were found to be 57.3 and 47.6%. Such high prevalence has never been seen in mainland China before. CONCLUSION: S. aureus isolates in Hainan have unique molecular characteristics, virulence gene and antibiotic resistance profiles, and main antibiotic resistance genes which may be associated with the special geographical location of Hainan and local trends in antibiotic use.


Asunto(s)
Farmacorresistencia Bacteriana/genética , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidad , Factores de Virulencia/genética , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Toxinas Bacterianas/genética , China , Farmacorresistencia Bacteriana/efectos de los fármacos , Exotoxinas/genética , Humanos , Leucocidinas/genética , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Staphylococcus aureus Resistente a Meticilina/patogenicidad , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/aislamiento & purificación , Virulencia/genética
18.
PLoS Genet ; 15(10): e1008223, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31626626

RESUMEN

Filamentous fungi rapidly evolve in response to environmental selection pressures in part due to their genomic plasticity. Parastagonospora nodorum, a fungal pathogen of wheat and causal agent of septoria nodorum blotch, responds to selection pressure exerted by its host, influencing the gain, loss, or functional diversification of virulence determinants, known as effector genes. Whole genome resequencing of 197 P. nodorum isolates collected from spring, durum, and winter wheat production regions of the United States enabled the examination of effector diversity and genomic regions under selection specific to geographically discrete populations. 1,026,859 SNPs/InDels were used to identify novel loci, as well as SnToxA and SnTox3 as factors in disease. Genes displaying presence/absence variation, predicted effector genes, and genes localized on an accessory chromosome had significantly higher pN/pS ratios, indicating a higher rate of sequence evolution. Population structure analyses indicated two P. nodorum populations corresponding to the Upper Midwest (Population 1) and Southern/Eastern United States (Population 2). Prevalence of SnToxA varied greatly between the two populations which correlated with presence of the host sensitivity gene Tsn1 in the most prevalent cultivars in the corresponding regions. Additionally, 12 and 5 candidate effector genes were observed to be under diversifying selection among isolates from Population 1 and 2, respectively, but under purifying selection or neutrally evolving in the opposite population. Selective sweep analysis revealed 10 and 19 regions that had recently undergone positive selection in Population 1 and 2, respectively, involving 92 genes in total. When comparing genes with and without presence/absence variation, those genes exhibiting this variation were significantly closer to transposable elements. Taken together, these results indicate that P. nodorum is rapidly adapting to distinct selection pressures unique to spring and winter wheat production regions by rapid adaptive evolution and various routes of genomic diversification, potentially facilitated through transposable element activity.


Asunto(s)
Ascomicetos/genética , Hongos/genética , Enfermedades de las Plantas/genética , Selección Genética/genética , Triticum/microbiología , Aclimatación/genética , Ascomicetos/patogenicidad , Evolución Molecular , Proteínas Fúngicas/genética , Hongos/patogenicidad , Genética de Población , Genómica , Interacciones Huésped-Patógeno/genética , Enfermedades de las Plantas/microbiología , Polimorfismo de Nucleótido Simple/genética , Sitios de Carácter Cuantitativo/genética , Triticum/genética , Triticum/crecimiento & desarrollo , Factores de Virulencia/genética
19.
Infect Immun ; 87(12)2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31591169

RESUMEN

As a strict human pathogen, Streptococcus pyogenes (group A Streptococcus, or GAS) causes a wide range of infections, from superficial to life-threatening diseases, upon dissemination. Thus, it is necessary to gain a better understanding of how GAS successfully overcomes host-mediated challenges and infects various host niches. We previously identified subcutaneous fitness (scf) genes in the clinically relevant wild-type (WT) GAS M1T1 5448 strain that are critical for fitness during murine soft-tissue infection at both 24 h and 48 h postinfection. The uncharacterized locus scfCDE was transcribed as an operon and is predicted to encode an ABC importer for nutrient uptake (e.g., amino acids). Individual scfCDE deletion mutants grew comparably to WT 5448 in rich medium but exhibited reduced fitness during competitive growth in murine soft tissue and in nutrient-limiting chemically defined medium (CDM). A deletion of the permease gene scfD resulted in a monoculture growth defect in CDM that could be rescued by addition of excess peptides, suggesting a role as an amino acid importer. Interestingly, the ΔscfC substrate-binding and ΔscfD permease mutants, but not the ΔscfE ATPase mutant, were highly attenuated in murine soft tissue. Moreover, all three genes were required for GAS survival in human blood, indicating their impact is not limited to superficial infections. As such, scfCDE plays an integral role in enhancing GAS adaptation during localized infection as well as dissemination to deeper host environments. Since scfCDE is conserved throughout Firmicutes, this work may contribute to the development of therapeutic strategies against GAS and other Gram-positive pathogens.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/genética , Infecciones Estreptocócicas/patología , Streptococcus pyogenes/genética , Streptococcus pyogenes/patogenicidad , Factores de Virulencia/genética , Transportadoras de Casetes de Unión a ATP/metabolismo , Animales , Regulación Bacteriana de la Expresión Génica , Ratones , Infecciones Estreptocócicas/genética , Virulencia/genética
20.
J Basic Microbiol ; 59(11): 1143-1153, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31577373

RESUMEN

Salmonella enterica serovar Typhimurium (S. Tm) is a major intracellular pathogen that infects humans and animals, and its survival and growth in macrophages is essential for its pathogenicity. More than 50 putative regulatory proteins are encoded by the S. Tm genome, but the functions of these regulatory proteins in mediating S. Tm pathogenicity are largely unknown. In this study, we investigated the biological function of the STM0030 gene, which encodes a putative LysR-type transcriptional regulator. We found that STM0030 is upregulated 2.8-5.7-fold during S. Tm growth in macrophages. Further, mutating this gene decreased bacterial growth in macrophages and attenuated virulence in mice. RNA-sequencing to investigate the regulatory function of STM0030 in S. Tm revealed that 447 genes were differentially expressed between the mutant and the wild-type strains; 429 of these genes were downregulated, suggesting that STM0030 mainly acts as a transcriptional activator. Moreover, the expression of gluconate, maltose, and hexose-p transport genes, as well as allantoin utilization genes were downregulated in the STM0030 mutant; this might be associated with the observed decrease in intracellular replication and pathogenicity of the mutant. Our findings suggest that STM0030 is a new pathogenicity-associated regulatory protein that broadens our understanding of the virulence regulatory network of S. Tm.


Asunto(s)
Proteínas Bacterianas/metabolismo , Salmonella typhimurium/patogenicidad , Factores de Transcripción/metabolismo , Factores de Virulencia/metabolismo , Animales , Proteínas Bacterianas/genética , Femenino , Regulación Bacteriana de la Expresión Génica , Macrófagos/microbiología , Ratones , Ratones Endogámicos BALB C , Mutación , Células RAW 264.7 , Salmonelosis Animal/microbiología , Salmonella typhimurium/genética , Salmonella typhimurium/crecimiento & desarrollo , Factores de Transcripción/genética , Virulencia , Factores de Virulencia/genética
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