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1.
Mem. Inst. Oswaldo Cruz ; 116: e200592, 2021. tab, graf
Article in English | LILACS | ID: biblio-1154883

ABSTRACT

BACKGROUND Paracoccidioidomycosis (PCM) is a systemic mycosis with high prevalence in Latin America that is caused by thermodimorphic fungal species of the Paracoccidioides genus. OBJECTIVES In this study, we used quantitative polymerase chain reaction (qPCR) to investigate the expression of genes related to the virulence of Paracoccidioides brasiliensis (Pb18) and P. lutzii (Pb01) strains in their mycelial (M) and yeast (Y) forms after contact with alveolar macrophages (AMJ2-C11 cell line) and fibroblasts (MRC-5 cell line). METHODS The selected genes were those coding for 43 kDa glycoprotein (gp43), enolase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), 14-3-3 protein (30 kDa), phospholipase, and aspartyl protease. FINDINGS In the Pb18 M form, the aspartyl protease gene showed the highest expression among all genes tested, both before and after infection of host cells. In the Pb18 Y form after macrophage infection, the 14-3-3 gene showed the highest expression among all genes tested, followed by the phospholipase and gp43 genes, and their expression was 50-fold, 10-fold, and 6-fold higher, respectively, than that in the M form. After fibroblast infection with the Pb18 Y form, the 14-3-3 gene showed the highest expression, followed by the phospholipase and aspartyl protease genes, and their expression was 25-fold, 10-fold, and 10-fold higher, respectively, than that in the M form. Enolase and aspartyl protease genes were expressed upon infection of both cell lines. After macrophage infection with the Pb01 Y form, the 14-3-3 gene showed the highest expression, followed by the phospholipase and aspartyl protease genes, and their expression was 18-fold, 12.5-fold, and 6-fold higher, respectively, than that in the M form. MAIN CONCLUSIONS In conclusion, the data show that the expression of the genes analysed may be upregulated upon fungus-host interaction. Therefore, these genes may be involved in the pathogenesis of paracoccidioidomycosis.


Subject(s)
Humans , Paracoccidioides/genetics , Paracoccidioidomycosis/genetics , Virulence Factors/genetics , Fibroblasts , Macrophages , Paracoccidioides/pathogenicity , Gene Expression , Latin America
2.
Article in English | WPRIM | ID: wpr-887716

ABSTRACT

Objective@#This study was performed to compare the genetic diversity, virulence, and antimicrobial resistance of @*Methods@#A total of 38 clinical strains and 19 strains from healthy individuals were isolated from the samples collected in Ma'anshan City, Anhui Province. Their taxonomy was investigated using concatenated @*Results@#The 57 @*Conclusions@#The taxonomy, virulence properties, and antibiotic resistance of


Subject(s)
Aeromonas/pathogenicity , Case-Control Studies , Drug Resistance, Bacterial/genetics , Genetic Variation , Humans , Virulence Factors/genetics
3.
Rev. chil. infectol ; 37(1): 37-44, feb. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1092720

ABSTRACT

Resumen Introducción: Staphylococcus aureus es uno de los patógenos con mayor prevalencia en el mundo, asociado a una alta tasa de mortalidad y un rápido desarrollo de resistencia a los antimicrobianos. A pesar de su patogenicidad, su seguimiento epidemiológico en México es escaso. Objetivo: Analizar la epidemiología molecular local y determinar el origen clonal de cepas resistentes a meticilina (RM) aisladas de pacientes internados en el Hospital Central "Dr. Ignacio Morones Prieto". Métodos: Se llevó a cabo un estudio prospectivo de corte transversal, de julio a diciembre de 2016. La caracterización de las cepas se realizó mediante genotipificación Spa, la determinación por RPC punto final de la frecuencia de genes de virulencia específicos y su antibiograma. Resultados: A partir de estos datos, se obtuvo que la prevalencia de S. aureus RM fue de 25,7%, destacando la presencia del tipo Spa t895 en 76% de las cepas resistentes y un patrón similar de susceptibilidad a antimicrobianos. Conclusión: Los resultados de este estudio indican que la prevalencia regional de SARM no se ha modificado en los últimos 10 años y proporcionan información valiosa del origen clonal y los factores de virulencia de las cepas de S. aureus aisladas en la región.


Abstract Background: Staphylococcus aureus is one of most prevalent pathogens in the world associated with a high mortality rate and a rapid development of resistance to antibiotics. Despite its pathogenicity, epidemiological monitoring in Mexico is scarce. Aim: To analyze the local molecular epidemiology and determine the clonal origin of methicillin-resistant (MR) strains isolated from patients admitted to Hospital "Dr. Ignacio Morones Prieto". Methods: A cross-sectional prospective study was carried out from July to December 2016. The characterization of the strains was carried out by Spa genotyping, frequency of specific virulence genes by PCR and antibiogram. Results: The prevalence of MRSA was 25.7%, highlighting the presence of the Spa type t895 in 76% of the resistant strains and a similar pattern of susceptibility to antibiotics. Conclusion: The results of this study indicate that the regional prevalence of MRSA has not changed in the last 10 years and provide valuable information on the clonal origin and the virulence factors of the strains of S. aureus isolated in the region.


Subject(s)
Humans , Staphylococcal Infections/microbiology , Staphylococcal Infections/epidemiology , Methicillin-Resistant Staphylococcus aureus/classification , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/genetics , Microbial Sensitivity Tests , Prevalence , Cross-Sectional Studies , Prospective Studies , Virulence Factors/genetics , Genotype , Mexico/epidemiology , Anti-Bacterial Agents/pharmacology
4.
Rev. Soc. Bras. Med. Trop ; 53: e20190429, 2020. tab, graf
Article in English | LILACS | ID: biblio-1057306

ABSTRACT

Abstract INTRODUCTION: Nosocomial and community acquired urinary tract infections (UTIs) are one of the most encountered infections in the world. METHODS: This study aimed to determine the antibiotic susceptibility, phylogeny, and virulence genes of 153 Escherichia coli strains isolated from UTIs. Antimicrobial susceptibility of the isolates to different classes of antimicrobials was determined by the VITEK-2 automated system. Presence of virulence genes and phylogenetic groups were investigated by PCR. RESULTS: Regarding susceptibility to antimicrobials, ampicillin resistance was most abundant (67.3%), followed by amoxicillin-clavulanic acid (50.9%); least abundant was resistance to amikacin (1.3%) and nitrofurantoin (1.3%). Multi drug resistance (MDR) was observed in 34.6% of the isolates, and all isolates were found to be susceptible to imipenem, meropenem and fosfomycine. The majority of the isolates belonged to the phylogenetic group B23 (35.9%), followed by A1 (20.9%), D1 (18.9%), D2 (12.4%), A0 (%5.9), B1 (3.9%) and B2 (1.9%). Among E. coli strains examined, 49% had iucD, 32.7% papE-F, 26.1% papC, 15% cnf2, 11.1% sfa, 7.8% cnf1, 1.3% afaE, 1.3% afaD, 1.3% hlyA, 0.7% f17a-A, 0.7% clpG and 0.7% eaeA genes. CONCLUSIONS Our research demonstrated that virulence factors were distributed among different phylogroup/subgroups, which play a role in UTIs pathogenesis in humans. For this reason, complex and detailed studies are required to determine the relationship between virulence factors and specific E. coli strains that cause UTIs in humans.


Subject(s)
Humans , Urinary Tract Infections/microbiology , Virulence Factors/genetics , Escherichia coli/drug effects , Escherichia coli/genetics , Escherichia coli Infections/microbiology , Anti-Bacterial Agents/pharmacology , Phylogeny , RNA, Ribosomal, 16S , Microbial Sensitivity Tests , Polymerase Chain Reaction , Escherichia coli/isolation & purification , Genotype
5.
Mem. Inst. Oswaldo Cruz ; 115: e200370, 2020. tab, graf
Article in English | SES-SP, LILACS, SES-SP | ID: biblio-1135225

ABSTRACT

BACKGROUND Bacillus anthracis is the aetiologic agent of anthrax, a re-emerging, septicaemic, haemorrhagic and lethal disease that affects humans, domestic ruminants and wildlife. Plasmids pXO1 and pXO2 are attributes that confer pathogenicity to B. anthracis strains. This bacterium was used as biological weapon in the World Wars and in the biological attack in the United States of America at 2001. B. anthracis is classified as a Tier 1 bioterrorism agent by the Centers for Diseases Control and Prevention. Anthrax is recognised as a re-emerging disease. Several studies concerning the dynamics of B. anthracis cycle in soil revealed that nonpathogenic B. anthracis strains due to lack of pXO2 plasmid are commonly found in some types of soil. OBJECTIVES This study aimed isolation and identification of B. anthracis spores in soil samples of the state of Rio de Janeiro, Brazil. METHODS Phenotypic and genotypic approaches were used to identify isolates including MALDI-TOF/MS, motility test, susceptibility to gamma phage and penicillin, survey for pag and cap genes as surrogates of pXO1 and pXO2 plasmids, respectively, and sequencing of 16SrRNA-encoding gene. Physicochemical analysis of the soil samples were carried out to describe soil characteristics. FINDINGS We observed the presence of one B. anthracis pXO1+ and pXO2- isolated from clay loam soil; one B. anthracis-like strain pXO1+ and pXO2-isolated from loamy sand; and 10 Bacillus spp. strains sensitive to phage-gamma that need better characterisation to define which their species were recovered from loamy sand. MAIN CONCLUSIONS This work showed promising results and it was the first study to report results from an active surveillance for B. anthracis in Brazil.


Subject(s)
Humans , Plasmids/analysis , Soil Microbiology , Spores, Bacterial , Bacillus anthracis/isolation & purification , DNA, Bacterial/genetics , Polymerase Chain Reaction/methods , Virulence Factors/genetics , Plasmids/genetics , Soil , Bacillus anthracis/genetics , Bacillus anthracis/pathogenicity , Bacterial Toxins , Virulence , Brazil , DNA, Bacterial/analysis , Sequence Analysis, DNA , Antigens, Bacterial
6.
Rev. chil. infectol ; 36(3): 312-317, jun. 2019. tab, graf
Article in Spanish | LILACS | ID: biblio-1013789

ABSTRACT

Resumen Introducción. Los factores de virulencia de las cepas de Vibrio cholerae no-O1, no-O139 no son claramente conocidos. La cepa de origen septicémico NN1 Vibrio cholerae no-O1, no-O139 fue secuenciada previamente mediante la plataforma Illumina, detectándose en su genoma un fragmento de la isla de patogenicidad VPaI-7 de V. parahaemolyticus. Objetivo: detectar los genes de virulencia vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF en cepas chilenas clínicas de V. cholerae no-O1, no-O139. Material y Métodos: Un total de 9 cepas chilenas de origen clínico de Vibrio cholerae no-O1, no-O139 aisladas entre 2006-2012 fueron analizadas mediante ensayos de reacción de polimerasa en cadena (RPC, en inglés PCR) convencional para los genes de secreción tipo III codificados en dicha isla: vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF. Adicionalmente se determinó la presencia de los genes de virulencia hylA y rtxA. Además, se realizaron ensayos de repetitive element palindromic PCR (REP-PCR) y Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Resultados: la mayoría (6/9) de las cepas chilenas de V. cholerae no-O1, no-O139 contiene todos los genes de secreción tipo III vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF, codificados en una isla de patogenicidad. Además, el total de las cepas (9/9) contiene los genes de virulencia hylA y rtxA. Conclusión: Estos resultados sugieren fuertemente la posibilidad que dichas cepas posean un potencial de virulencia importante en seres humanos.


Backgound: The virulence factors of the Vibrio cholerae non-O1, non-O139 strains are not clearly known. The strain of septicemic origin NN1 Vibrio cholerae non-O1, non-O139 was sequenced previously by the Illumina platform. A fragment of the pathogenicity island VPaI-7 of V. parahaemolyticus was detected in its genome. Aim: To detect the virulence genes vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF in Chilean strains of V. cholerae non-O1, non-O139. Methods: A total of 9 Chilean strains of clinical origin of Vibrio cholerae non-O1, non-O139 isolated between 2006-2012 were analyzed by conventional PCR assays for type III secretion genes encoded on that island: vcsN2, vcsC2, vcsV2, vspD, toxR2 and vopF. Additionally, the presence of the virulence genes hylA and rtxA was determined. In addition, REP-PCR and ERIC-PCR assays were performed. Results: most (6/9) Chilean V. cholerae non-O1, non-O139 strains contain the type III secretion genes vcsN2, vcsC2, vcsV2, vspD, toxR2 and vopF, encoded in an island of pathogenicity. In addition, all (9/9) the strains contain the virulence genes hylA and rtxA. Conclusion: These results strongly suggest the possibility that those strains possess an important virulence potential in humans.


Subject(s)
Humans , Bacterial Proteins/genetics , Transcription Factors/genetics , Vibrio cholerae/genetics , Virulence Factors/genetics , Vibrio cholerae non-O1/genetics , Genomic Islands/genetics , DNA-Binding Proteins/genetics , Type III Secretion Systems/genetics , Bacterial Toxins/genetics , Vibrio cholerae/isolation & purification , Vibrio cholerae/pathogenicity , Chile , Polymerase Chain Reaction , Sequence Analysis, DNA , Vibrio cholerae non-O1/isolation & purification , Vibrio cholerae non-O1/pathogenicity , Hemolysin Proteins/genetics
7.
Prensa méd. argent ; 105(2): 82-91, apr 2019. tab, fig
Article in English | LILACS, BINACIS | ID: biblio-1025704

ABSTRACT

Staphylococcus aureus is one of the most important pathogenic type to humans, and the most common species responsible for a wide range of diseases such as furuncles, various abscesses, wounds abscesses resulting from surgical operations, dermatitis, soft tissue inflammation, arthritis, bones inflammation, bronchial pneumonia, inflammation of internal parts of the heart and injuries caused by toxins such as toxic shock syndorome and staphylococcus aureus syndrome and food poisoning. The current study aimed by finding the genes responsible for the virulence factors in S. aureus isolates by using the Single and Multiplex PCR mechanism (technology). A total of 60 specimens (urine, burn swabs, wound swaabs) from different clinical cases were collected from patients (in different age groups) who admitted to several health centers in Al-Diwaniyah Teaching Hospital, Iraq, during a period extending from October 2016 to January 2017. Some virulence factors were investigated for 30 isolate only of MRSA using Single and Multiplex PCR for detection virulence factor genes which both coa gene encoding production of coagulase, clfA gene encoding for clumpting factor, spa gene encoding for protein A, fnbA gene encoding for fibronectin binding proteins, luks gene encoding prouction of Panton Valentine Leukocidin (PVL). Results 30 (100%) were possess coa, clfA, spa and fnbA genes, 13 (43.3%) were possess luks gene


Subject(s)
Humans , Specimen Handling/instrumentation , Staphylococcal Protein A , Staphylococcus aureus/pathogenicity , Medical Records/statistics & numerical data , Polymerase Chain Reaction , Fibronectins , Coagulase , Coenzyme A/classification , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Leukocidins
8.
Braz. j. infect. dis ; 23(2): 134-138, Mar.-Apr. 2019. tab, graf
Article in English | LILACS | ID: biblio-1039223

ABSTRACT

ABSTRACT This study characterized 30 MRSA isolates from intensive care unit (ICU) environment and equipment surfaces and healthy children. The SCCmec types I, IVa and V were detected in HA-MRSA isolates while CA-MRSA showed the SCCmec type IVa and V. Most isolates were classified as agr group II. All isolates presented the sei gene, and only HA-MRSA were positive for etb e tst genes. Three genotypes were related to Pediatric (ST5/SCCmecIV) and Berlin (ST45/SCCmecIV) clones. The present study showed molecular similarity between CA- and HA-MRSA isolates in hospital and community settings in a Brazilian region.


Subject(s)
Humans , Cross Infection/microbiology , Community-Acquired Infections/microbiology , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/genetics , Intensive Care Units/statistics & numerical data , Staphylococcal Infections/genetics , Staphylococcal Infections/microbiology , Brazil , Virulence Factors/isolation & purification , Virulence Factors/genetics , Equipment and Supplies, Hospital/microbiology , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Genotype
9.
Rev. Soc. Bras. Med. Trop ; 52: e20190089B, 2019. tab, graf
Article in English | LILACS | ID: biblio-1041519

ABSTRACT

Abstract INTRODUCTION The relationships between phagocytosis, and mucoid phenotype, plasmid profile and virulence, and resistance genetic characteristics of Klebsiella pneumoniae clinical isolates were evaluated. METHODS Thirty isolates were used to determine the mucoid aspect. Four were selected for analysis of phagocytosis by alveolar macrophages. RESULTS Thirty percent of the samples presented the mucoid phenotype. The phagocytosis rate ranged from 21.5% to 43.43%. Phagocytosis was not correlated with the plasmid profile, but was apparently correlated with mucoid phenotype and antibiotic susceptibility. CONCLUSIONS: Several virulence factors act in parallel in K. pneumoniae to impair host defense.


Subject(s)
Humans , Phagocytosis/genetics , Virulence/genetics , Drug Resistance, Microbial/genetics , Virulence Factors/genetics , Klebsiella pneumoniae/genetics , Anti-Bacterial Agents/pharmacology , Phagocytosis/physiology , Phenotype , Plasmids , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/pathogenicity
10.
Rev. Soc. Bras. Med. Trop ; 52: e20180285, 2019. tab, graf
Article in English | LILACS | ID: biblio-1041544

ABSTRACT

Abstract INTRODUCTION Salmonella enterica serovar Panama belongs to the D1 serogroup and is frequently associated with nontyphoidal salmonellosis in humans. This study aimed to characterize isolates collected from Northeast Brazil by phenotypic and molecular methods. METHODS Forty four S. Panama strains were examined for antimicrobial susceptibility, virulence genes, and pulsed field gel electrophoresis (PFGE) types. RESULTS All strains were susceptible to antibiotics (except for streptomycin), presented classical virulence factors, and could be clustered into four groups and 18 pulsotypes. CONCLUSIONS This work calls for continuous surveillance for the emergence of antibiotic resistance and new clones in a geographical area.


Subject(s)
Animals , Salmonella enterica/genetics , Virulence Factors/genetics , Genetic Variation , Brazil , Microbial Sensitivity Tests , Electrophoresis, Gel, Pulsed-Field , Salmonella enterica/isolation & purification , Salmonella enterica/drug effects , Salmonella enterica/pathogenicity , Drug Resistance, Multiple, Bacterial , Anti-Bacterial Agents/pharmacology
11.
Rev. Soc. Bras. Med. Trop ; 52: e20180499, 2019. tab
Article in English | LILACS | ID: biblio-1013306

ABSTRACT

Abstract INTRODUCTION : Escherichia coli ranks among the most common sources of urinary tract infections (UTI). METHODS: Between November 2015 and August 2016, 90 isolates of E. coli were isolated from patients at Rize Education and Research Hospital in Turkey. Antibiotic susceptibility was determined for all isolates using the Kirby-Bauer disk diffusion method. These E. coli isolates were also screened for virulence genes, β-lactamase coding genes, quinolone resistance genes, and class 1 integrons by PCR. RESULTS: With respect to the antibiotic resistance profile, imipenem and meropenem were effective against 98% and 90% of isolates, respectively. A high percentage of the isolates showed resistance against β lactam/β lactamase inhibitor combinations, quinolones, and cephalosporins. PCR results revealed that 63% (57/90) of the strains carried class 1 integrons. In addition, a high predominance of extended-spectrum β-lactamases (ESBLs) was observed. The qnrA, qnrB, and qnrS genes were found in 24 (26.6%), 6 (6.6%), and 3 (3.3%), isolates, respectively. The most common virulence gene was fim (82.2%).The afa, hly, and cnf1 genes were detected in 16.6%, 16.6%, and 3.3% of isolates, respectively. Moreover, we observed eleven different virulence patterns in the 90 E. coli isolates. The most prevalent pattern was fım, while hly-fım, afa-aer-cnf-fım, aer-cnf, afa-aer, and afa-cnf-fım patterns were less common. CONCLUSIONS: Most of the E. coli virulence genes investigated in this study were observed in E. coli isolates from UTI patients. Virulence genes are very important for the establishment and maintenance of infection.


Subject(s)
Humans , Male , Female , Urinary Tract Infections/drug therapy , Drug Resistance, Multiple, Bacterial , Virulence Factors/genetics , Escherichia coli/genetics , Escherichia coli/pathogenicity , Escherichia coli Infections/genetics , Escherichia coli Infections/drug therapy , Anti-Bacterial Agents/pharmacology , Turkey , Urinary Tract Infections/microbiology , beta-Lactamases , Microbial Sensitivity Tests , Quinolones , Escherichia coli/isolation & purification
12.
Rev. Soc. Bras. Med. Trop ; 52: e20190095, 2019. tab, graf
Article in English | LILACS | ID: biblio-1013299

ABSTRACT

Abstract INTRODUCTION Staphylococcus aureus is a major nosocomial pathogen that is associated with high virulence and the rapid development of drug resistance. METHODS We analyzed and compared the antimicrobial resistance, virulence profiles, and molecular epidemiology of 67 S. aureus strains, including 36 methicillin-sensitive (MSSA) and 31 methicillin-resistant (MRSA) strains recovered from a public hospital located in south-eastern Brazil. RESULTS The clones circulating in this hospital presented a great diversity, and the majority of the strains were related to clones responsible for causing worldwide epidemics: these included USA100 (New York/Japan clone), USA300, and USA600. The 31 MRSA (22 SCCmecII and 9 SCCmecIV) and 36 MSSA strains exhibited low resistance against gentamicin and trimethoprim/sulfamethoxazole. No MRSA strain showed resistance to tetracycline. Virulence gene carriage was more diverse and abundant in MSSA than in MRSA. Of the evaluated adhesion-related genes, ebpS was the most prevalent in both MSSA and MRSA strains. The genes bbp and cna showed a strong association with MSSA strains. CONCLUSIONS Our findings reinforce the idea that MSSA and MRSA strains should be carefully monitored, owing to their high pathogenic potential.


Subject(s)
Humans , Staphylococcus aureus/drug effects , Staphylococcus aureus/genetics , Methicillin Resistance , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Anti-Bacterial Agents/pharmacology , Staphylococcal Infections/epidemiology , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/classification , Virulence/genetics , Brazil/epidemiology , Microbial Sensitivity Tests , Molecular Epidemiology , Tertiary Care Centers , Hospitals, Public
13.
Braz. j. infect. dis ; 22(6): 487-494, Nov.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-984020

ABSTRACT

ABSTRACT Background: The rate of methicillin-resistant Staphylococcus aureus (MRSA) among the total of S. aureus isolates decreased to 35.3% in 2017 in China. It is unclear whether the molecular characteristics of S. aureus isolates have changed as the rate decreased. Objective: This study aimed to investigate the molecular characteristics and virulence genes profile of S. aureus isolates causing bloodstream infection and analyze the correlation between the prevalence rates of the common sequence types and MRSA. Methods: A total of 112 S. aureus strains from eight hospitals of four cities, including 32 MRSA isolates, were identified and evaluated through multilocus sequence typing, spa typing, and determination of virulence genes. Results: Twenty-five STs were identified, of which ST5 (21.4%) was the most prevalent, whereas the prevalence of ST239 correlated with the rate of MRSA among all S. aureus isolates. Forty-six spa types were identified, of which t2460 (14.3%) was the most common. clfa, hla, seb, fnbA and hlb were the prevailing virulence genes. 81.3% MRSA and 45.0% methicillin-sensitive S. aureus (MSSA) isolates harbored six or more tested virulence genes. ST5-t2460, seldom noted in bloodborne S. aureus isolates in China, was the most common clone. The prevalence of harboring six or more virulence genes in ST5-t2460 and ST188-t189 were 93.8% and 8.3%, respectively. Conclusion: ST5-t2460 was the most common clone in S. aureus causing bloodstream infection followed by ST188-t189, which had never been noted in China before. Moreover, ST5-t2460 harbored more virulence genes than ST188-t189, and the prevalence of ST239 clone decreased with the proportion of MRSA among all S. aureus isolates.


Subject(s)
Humans , Staphylococcus aureus/genetics , Staphylococcus aureus/pathogenicity , Virulence/genetics , Bacteremia/virology , Phenotype , Microbial Sensitivity Tests , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Molecular Typing , Multilocus Sequence Typing , Genotype
14.
J. pediatr. (Rio J.) ; 94(4): 380-389, July-Aug. 2018. tab, graf
Article in English | LILACS | ID: biblio-954633

ABSTRACT

Abstract Objective: Staphylococcus aureus is responsible for a large number of infections in pediatric population; however, information about the behavior of such infections in this population is limited. The aim of the study was to describe the clinical, epidemiological, and molecular characteristics of infections caused by methicillin-susceptible and resistant S. aureus (MSSA-MRSA) in a pediatric population. Method: A cross-sectional descriptive study in patients from birth to 14 years of age from three high-complexity institutions was conducted (2008-2010). All patients infected with methicillin-resistant S. aureus and a representative sample of patients infected with methicillin-susceptible S. aureus were included. Clinical and epidemiological information was obtained from medical records and molecular characterization included spa typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). In addition, staphylococcal cassette chromosome mec (SCCmec) and virulence factor genes were detected. Results: A total of 182 patients, 65 with methicillin-susceptible S. aureus infections and 117 with methicillin-resistant S. aureus infections, were included in the study; 41.4% of the patients being under 1 year. The most frequent infections were of the skin and soft tissues. Backgrounds such as having stayed in day care centers and previous use of antibiotics were more common in patients with methicillin-resistant S. aureus infections (p ≤ 0.05). Sixteen clonal complexes were identified and methicillin-susceptible S. aureus strains were more diverse. The most common cassette was staphylococcal cassette chromosomemec IVc (70.8%), which was linked to Panton-Valentine leukocidin (pvl). Conclusions: In contrast with other locations, a prevalence of infections in children under 1 year of age in the city could be observed; this emphasizes the importance of epidemiological knowledge at the local level.


Resumo Objetivo: O Staphylococcus aureus é responsável por um grande número de infecções na população pediátrica; contudo, as informações sobre o comportamento dessas infecções nessa população são limitadas. O objetivo do estudo foi descrever as características clínicas, epidemiológicas e moleculares de infecções causadas por Staphylococcus aureus suscetíveis e resistentes à meticilina (MSSA-MSRA) em uma população pediátrica. Método: Um estudo transversal descritivo foi realizado em pacientes entre 0 e 14 anos de idade de três instituições de alta complexidade (2008-2010). Todos os pacientes infectados com S. aureus resistentes à meticilina e uma amostra representativa de pacientes infectados com S. aureus suscetíveis à meticilina foram incluídos. As informações clínicas e epidemiológicas foram obtidas de prontuários médicos, e a caracterização molecular incluiu tipagem spa, Eletroforese em Gel de Campo Pulsado (PFGE) e Tipagem de sequências multilocus (MLST). Além disso, o Cassete Cromossômico Estafilocócico mec (SCCmec) e genes de fatores de virulência foram detectados. Resultados: 182 pacientes, 65 com infecções por S. aureus suscetíveis à meticilina e 117 com infecções por S. aureus resistentes à meticilina, foram incluídos no estudo; 41,4% dos pacientes com menos de um ano de idade. As infecções mais frequentes foram da pele e dos tecidos moles. Os históricos como internações em centros de atendimento e o uso prévio de antibióticos foram mais comuns em pacientes com infecções por S. aureus resistentes à meticilina (p ≤ 0,05). Dezesseis complexos clonais foram identificados, e as cepas de S. aureus suscetíveis à meticilina foram mais diversificadas. O cassete mais comum foi o Cassete Cromossômico Estafilocócicomec IVc (70,8%), relacionado à leucocidina de panton-valentine (pvl). Conclusões: Em comparação a outros locais, observamos uma prevalência de infecções em crianças com menos de um ano de idade na cidade; o que enfatiza a importância de conhecer a epidemiologia em nível local.


Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Skin Diseases, Infectious/microbiology , Staphylococcal Infections/microbiology , Soft Tissue Infections/microbiology , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/genetics , Skin Diseases, Infectious/diagnosis , Staphylococcal Infections/diagnosis , Cross-Sectional Studies , Electrophoresis, Gel, Pulsed-Field , Soft Tissue Infections/diagnosis , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Multilocus Sequence Typing
15.
Rev. Soc. Bras. Med. Trop ; 51(3): 361-363, Apr.-June 2018. graf
Article in English | LILACS | ID: biblio-1041462

ABSTRACT

Abstract INTRODUCTION: The pathogenic versatility of Staphylococcus aureus is attributed to various virulence genes, including enterotoxins and hemolysins. METHODS: Here, the virulence genes in 177 nosocomial MRSA strains in Porto Alegre, Brazil were detected by PCR. RESULTS: The overall prevalence rates were as follows: sea, 4.5%; pvl, 18.6%; tst, 27.7%; hla, 87.6%; and hld, 90.4%. No strain contained all tested genes. However, there was frequent coexistence of tst with pvl and hla with hld (40.7% and 26.6%, respectively). CONCLUSIONS: Horizontal transfer of virulence genes is very common in S. aureus, as suggested by the frequent coexistence of several virulence genes.


Subject(s)
Humans , Virulence/genetics , Virulence Factors/genetics , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Polymerase Chain Reaction , Cross-Sectional Studies , Methicillin-Resistant Staphylococcus aureus/genetics
16.
Braz. j. microbiol ; 49(1): 189-199, Jan.-Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-889209

ABSTRACT

ABSTRACT Nine Legionella pneumophila strains isolated from cooling towers and a standard strain (L. pneumophila serogroup 1, ATCC 33152, Philadelphia 1) were analyzed and compared in terms of motility, flagella structure, ability to form biofilms, enzymatic activities (hemolysin, nucleases, protease, phospholipase A, phospholipase C, acid phosphatase, alkaline phosphatase and lipase), hemagglutination capabilities, and pathogenicity in various host cells (Acanthamoeba castellanii ATCC 30234, mouse peritoneal macrophages and human peripheral monocytes). All the isolates of bacteria appeared to be motile and polar-flagellated and possessed the type-IV fimbria. Upon the evaluation of virulence factors, isolate 4 was found to be the most pathogenic strain, while 6 out of the 9 isolates (the isolates 1, 2, 3, 4, 5, and 7) were more virulent than the ATCC 33152 strain. The different bacterial strains exhibited differences in properties such as adhesion, penetration and reproduction in the hosts, and preferred host type. To our knowledge, this is the first study to compare the virulence of environmental L. pneumophila strains isolated in Turkey, and it provides important information relevant for understanding the epidemiology of L. pneumophila.


Subject(s)
Humans , Animals , Female , Mice , Bacterial Proteins/metabolism , Legionella pneumophila/metabolism , Virulence Factors/metabolism , Bacterial Proteins/genetics , Turkey/epidemiology , Legionnaires' Disease/microbiology , Legionella pneumophila/isolation & purification , Legionella pneumophila/genetics , Virulence Factors/genetics , Environmental Microbiology , Macrophages/microbiology , Mice, Inbred BALB C
17.
Braz. j. med. biol. res ; 51(10): e7423, 2018. tab, graf
Article in English | LILACS | ID: biblio-951708

ABSTRACT

Epithelial cell migration is an essential response to enteric pathogens such as enteropathogenic Escherichia coli (EPEC). This study aimed to investigate the effects of EPEC infection on intestinal epithelial cell migration in vitro, as well as the involvement of type III secretion system (T3SS) and Rho GTPases. Crypt intestinal epithelial cells (IEC-6) were infected with EPEC strains (E2348/69, ΔescF, and the LDI001 strain isolated from a malnourished Brazilian child) and commensal E. coli HS. Wound migration and cell death assays were performed at different time-points. Transcription and expression of Rho GTPases were evaluated using real-time PCR and western blotting. Overall, EPEC E2348/69 reduced migration and increased apoptosis and necrosis levels compared to EPEC LDI001 and E. coli HS strains. Moreover, EPEC LDI001 impaired cell migration at a higher level than E. coli HS and increased necrosis after 24 hours compared to the control group. The different profiles of virulence genes between the two wild-type EPEC strains, characterized by the absence of espL and nleE genes in the LDI001, might explain the phenotypic results, playing significant roles on cell migration impairment and cell death-related events. Moreover, the type III secretion system is determinant for the inhibition of intestinal epithelial cell migration by EPEC 2348/69, as its deletion prevented the effect. Active Rac1 concentrations were increased in E2348/69 and LDI001-infected cells, while the T3SS-deficient strain did not demonstrate this activation. This study contributes with valuable insight to characterize the mechanisms involved in the impairment of intestinal cell migration induced by EPEC.


Subject(s)
Humans , Cell Movement/physiology , rho GTP-Binding Proteins/physiology , Virulence Factors/genetics , Epithelial Cells/microbiology , Enteropathogenic Escherichia coli/pathogenicity , Type III Secretion Systems/physiology , Blotting, Western , Apoptosis , Virulence Factors/physiology , Real-Time Polymerase Chain Reaction , Flow Cytometry
18.
Braz. j. microbiol ; 49(supl.1): 93-100, 2018. tab, graf
Article in English | LILACS | ID: biblio-974332

ABSTRACT

Abstract Klebsiella pneumoniae is important human and animal pathogen that causes a wide spectrum of infections. In this study, isolates from cattle nasal swabs samples were identified by 16S rRNA, and to evaluate the antimicrobial susceptibility, virulence gene carrying levels, and multilocus sequence typing of K. pneumoniae isolates. 33 isolates of K. pneumoniae were isolated and identified in 213 nasal swabs samples, of which 12 were hypervirulent K. pneumoniae strains. Extended Spectrum Beta-Lactamases genes were found in 93.4% of the strains. Of which, TEM was the most prevalent (93.4%), followed by CTX-M and SHV were 57.6% and 39.4%, respectively. A main mutation pattern of quinoloneresistance-determining region, Thr83-Ieu and Asp87-Asn in gyrA and Ser87-Ile in parC, was detected in 33 K. pneumoniae isolates. All the isolates harbored at least two virulence factor genes, with ureA (97.0%) and wabG (91.0%) exhibiting high carriage rates in 33 K. pneumoniae isolates. MLST revealed 7 sequence types, of which 3 STs (2541, 2581 and 2844) were newly assigned. Using eBURST, ST2844 and ST2541 were assigned to new clonal complex 2844. Our study provides evidence and biological characteristics of K. pneumoniae isolates from cattle upper respiratory tract in Southwest China.


Subject(s)
Animals , Cattle , Bacterial Proteins/genetics , Klebsiella Infections/veterinary , Cattle Diseases/microbiology , Drug Resistance, Multiple, Bacterial , Virulence Factors/genetics , Klebsiella pneumoniae/isolation & purification , Klebsiella pneumoniae/drug effects , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Klebsiella Infections/microbiology , China , Virulence Factors/metabolism , Multilocus Sequence Typing , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/metabolism
19.
Braz. j. microbiol ; 49(supl.1): 107-112, 2018. tab, graf
Article in English | LILACS | ID: biblio-1039271

ABSTRACT

Abstract Avian pathogenic Escherichia coli (APEC) isolates from apparently healthy free range helmeted guineafowl were characterized. Most of them had a high frequency of virulence associated genes, multi drug resistance and high pathogenicity. We demonstrated that helmeted guineafowl have potential to transmit antibiotic resistant APEC to other species including humans.


Subject(s)
Animals , Bird Diseases/microbiology , Escherichia coli/isolation & purification , Escherichia coli Infections/veterinary , Escherichia coli Proteins/genetics , Escherichia coli Proteins/metabolism , Drug Resistance, Bacterial , Virulence Factors/genetics , Virulence Factors/metabolism , Galliformes/microbiology , Escherichia coli/classification , Escherichia coli/drug effects , Escherichia coli/genetics , Escherichia coli Infections/microbiology , Anti-Bacterial Agents/pharmacology
20.
Braz. j. microbiol ; 49(supl.1): 224-228, 2018. tab, graf
Article in English | LILACS | ID: biblio-1039272

ABSTRACT

ABSTRACT Enterobacter cloacae and E. aerogenes have been increasingly reported as important opportunistic pathogens. In this study, a high prevalence of multi-drug resistant isolates from Brazil, harboring several β-lactamase encoding genes was found. Several virulence genes were observed in E. aerogenes, contrasting with the E. cloacae isolates which presented none.


Subject(s)
Humans , Male , Female , Adult , Middle Aged , Bacterial Proteins/metabolism , beta-Lactamases/metabolism , Enterobacter cloacae/isolation & purification , Enterobacter aerogenes/isolation & purification , Virulence Factors/metabolism , Enterobacteriaceae Infections/microbiology , Phylogeny , Bacterial Proteins/genetics , Virulence , beta-Lactamases/genetics , Brazil , Microbial Sensitivity Tests , Enterobacter cloacae/classification , Enterobacter cloacae/enzymology , Enterobacter cloacae/genetics , Enterobacter aerogenes/classification , Enterobacter aerogenes/enzymology , Enterobacter aerogenes/genetics , Virulence Factors/genetics , Middle Aged , Anti-Bacterial Agents/pharmacology
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