scholarly journals Virulence Factors Associated with Pediatric Shigellosis in Brazilian Amazon

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Carolinie Batista Nobre da Cruz ◽  
Maria Carolina Scheffer de Souza ◽  
Paula Taquita Serra ◽  
Ivanildes Santos ◽  
Antonio Balieiro ◽  
...  
Keyword(s):  
Human Health ◽  
Virulence Factors ◽  
Health Problem ◽  
Virulence Genes ◽  
Bacillary Dysentery ◽  
Brazilian Amazon ◽  
Clinical Isolates ◽  
Pathogenic Potential ◽  
Factors Associated ◽  
Etiologic Study

Shigellosis is a global human health problem and the incidence is highest among children. In the present work, mainShigellavirulence genes was examined by PCR and compared to symptoms of pediatric shigellosis. ThirtyShigellaisolates were identified from an etiologic study at which 1,339 children ranging 0–10 years old were enrolled.S. flexneriwas the most frequent species reaching 60.0% of isolates, 22.2% wereS. sonnei, and 6.6% were bothS. dysenteriaeandS. boydii. AllShigellainfected children had diarrhea, but not all were accompanied by others symptoms of bacillary dysentery. Among major virulence genes, the PCR typing revealedipaBCDwas present in all isolates, followed byIpaH7.8,set-1A,set-1B, sen/ospD3, virF,andinvE. The pathogenic potential of the ShET-1B subunit was observed in relation to dehydration (P<0.001) and ShET-2 related to the intestinal injury (P=0.033) evidenced by the presence of bloody diarrhea. Our results show associations among symptoms of shigellosis and virulence genes of clinical isolates ofShigellaspp.

scholarly journals Stunting in children under five years old is still a health problem in the Western Brazilian Amazon: a population-based study in Assis Brasil, Acre, Brazil

2016 ◽  
Vol 21 (7) ◽  
pp. 2257-2266 ◽  
Author(s):  
Saulo Augusto Silva Mantovani ◽  
Alanderson Alves Ramalho ◽  
Thasciany Moraes Pereira ◽  
Fernando Luiz Cunha Castelo Branco ◽  
Humberto Oliart-Guzmán ◽  
...  
Keyword(s):  
Health Problem ◽  
Public Health Problem ◽  
Wealth Index ◽  
Brazilian Amazon ◽  
Population Based ◽  
World Health ◽  
Important Public Health Problem ◽  
Children Under Five ◽  
Under Five ◽  
Factors Associated

Abstract Despite the process of nutritional transition in Brazil, in some places, such as the Amazon region, stunting is still an important public health problem. We identified the prevalence and factors associated with stunting in children under five years old residing in the urban area of Assis Brasil. A survey was conducted in which a questionnaire on socioeconomic, maternal and children’s conditions was applied, and height or length was measured. The children with height for age index below -2 Z-scores were considered stunted, according to the criteria by the World Health Organization. Four hundred and twenty-eight children were evaluated. Of these, 62 were stunted. Factors associated with stunting, according to adjusted models, were: the presence of open sewer, the wealth index for households, the receipt of governmental financial aid and the mother’s height, age and education. Therefore, it was observed that family and the mother’s characteristics as well as environmental and socioeconomic factors were closely related to the occurrence of stunting in the population studied, and such nutritional disturbance is still a health problem in the Brazilian Amazon.

scholarly journals Analysis of virulence factors and emm typing of Streptococcus pyogenes clinical isolates.

2019 ◽  
Author(s):  
Gustavo Enck Sambrano ◽  
Gustavo P Riboldi ◽  
Keli C Reiter ◽  
Thiago Galvão da Silva Paim ◽  
Neidmar Correa Tolfo ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Streptococcus Pyogenes ◽  
Virulence Genes ◽  
Clinical Isolates ◽  
Pcr Analysis ◽  
Tissue Tropism ◽  
Factors Analysis ◽  
Wide Range ◽  
Group A ◽  
Micro Organisms

Background: Streptococcus pyogenes, a Group A streptococci (GAS), is an important human pathogen that causes a wide range of infections. Methods: Twenty five clinical isolates of S. pyogenes were submitted to an emm typing and to a Real-time PCR analysis for 23 important virulence factors. Results: Fourteen emm types were found and the emm1 type was the most prevalent. The majority of the isolates were classified as emm pattern E, followed by A-C3. No pattern D was found. Among the virulence factors, the most prevalent were SpeG, Slo, C5a-peptidase and SPNA. Phage encoded virulence genes were also found among the strains, such as mf-2, SpeJ and SpeL. Discussion: The emm1 type was the most prevalent while the 13 others M types were distributed along the strains. No tissue tropism was found on the isolates. The virulence factors analysis demonstrated that chromosomally and phage-encoded genes were found, which confers a potential for high virulent micro-organisms.

scholarly journals Analysis of virulence factors and emm typing of Streptococcus pyogenes clinical isolates.

2019 ◽  
Author(s):  
Gustavo Enck Sambrano ◽  
Gustavo P Riboldi ◽  
Keli C Reiter ◽  
Thiago Galvão da Silva Paim ◽  
Neidmar Correa Tolfo ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Streptococcus Pyogenes ◽  
Virulence Genes ◽  
Clinical Isolates ◽  
Pcr Analysis ◽  
Tissue Tropism ◽  
Factors Analysis ◽  
Wide Range ◽  
Group A ◽  
Micro Organisms

Background: Streptococcus pyogenes, a Group A streptococci (GAS), is an important human pathogen that causes a wide range of infections. Methods: Twenty five clinical isolates of S. pyogenes were submitted to an emm typing and to a Real-time PCR analysis for 23 important virulence factors. Results: Fourteen emm types were found and the emm1 type was the most prevalent. The majority of the isolates were classified as emm pattern E, followed by A-C3. No pattern D was found. Among the virulence factors, the most prevalent were SpeG, Slo, C5a-peptidase and SPNA. Phage encoded virulence genes were also found among the strains, such as mf-2, SpeJ and SpeL. Discussion: The emm1 type was the most prevalent while the 13 others M types were distributed along the strains. No tissue tropism was found on the isolates. The virulence factors analysis demonstrated that chromosomally and phage-encoded genes were found, which confers a potential for high virulent micro-organisms.

scholarly journals Determination of putative virulence factors among clinical isolates of enterococci isolated from a military hospital in the eastern province of Saudi Arabia

2020 ◽  
Vol 8 (11) ◽  
pp. 3860
Author(s):  
Siju Kankalil George ◽  
M. R. Suseela ◽  
Saleh El Safi ◽  
El Moiez Ali El Nagi ◽  
Ahmed Adlan Mohammed Adam ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Virulence Factors ◽  
Clinical Isolates ◽  
Military Hospital ◽  
Clinical Samples ◽  
Haemolytic Activity ◽  
Eastern Province ◽  
Pathogenic Potential ◽  
Life Threatening ◽  
Susceptibility Patterns

Background: The pathogenic potential of enterococci to produce life-threatening infections is well-documented. The scientific community has, of late, evinced a renewed interest in the putative virulence factors of enterococci. Objective of the study was to determine the putative virulence factors of clinically isolated Enterococcus species from a military hospital and to describe the association between virulence factors and vancomycin susceptibility.Methods: A total of 245 enterococci were isolated from clinical samples collected from KFMMC, a leading military hospital in the eastern province of Saudi Arabia. Following species identification and antimicrobial susceptibility testing using the Vitek 2 system; the isolates were tested for the production of caseinase, gelatinase, biofilm, and presence of haemolysin.Results: Among the enterococcal isolates, 36.7% produced caseinase, 38% produced gelatinase, 24.1% exhibited biofilm formation, and 30.6% were positive for haemolytic activity. A significant association between vancomycin susceptibility patterns and the virulence factors, gelatinase and haemolytic activity, were noted. No significant associations were observed between vancomycin susceptibility patterns and the presence of caseinase or the formation of biofilms.Conclusions: Virulence factors are invariably produced by several clinical isolates of enterococci in our hospital, and some virulence factors are associated with vancomycin susceptibility.

scholarly journals Prevalence of pathogenic Klebsiella pneumoniae based on PCR capsular typing harbouring carbapenemases encoding genes in Uganda tertiary hospitals

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Kenneth Ssekatawa ◽  
Denis K. Byarugaba ◽  
Jesca L. Nakavuma ◽  
Charles D. Kato ◽  
Francis Ejobi ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Virulence Factors ◽  
Carbapenem Resistance ◽  
Clinical Isolates ◽  
Genotypic Resistance ◽  
Pathogenic Potential ◽  
Phenotypic Resistance ◽  
Tertiary Hospitals ◽  
Encoding Genes

Abstract Background Klebsiella pneumoniae is an opportunistic pathogen that has been implicated as one of commonest cause of hospital and community acquired infections. The K. pneumoniae infections have considerably contributed to morbidity and mortality in patients with protracted ailments. The capacity of K. pneumoniae to cause diseases depends on the presence of an array virulence factors. Coexistence and expression of virulence factors and genetic determinants of antibiotic resistance complicates treatment outcomes. Thus, emergence of pathogenic MDR K. pneumoniae poses a great threat to the healthcare system. However, the carriage of antibiotic resistance among pathogenic K. pneumoniae is yet to be investigated in Uganda. We sought to investigate the carbapenem resistance profiles and pathogenic potential based on capsular serotypes of K. pneumoniae clinical isolates. Methods This was a cross sectional study involving use of archived Klebsiella pneumoniae isolates collected between January and December, 2019 at four tertiary hospitals in Uganda. All isolates were subject to antimicrobial susceptibility assays to determine phenotypic antibiotic resistance, pentaplex PCR to detect carbapenemases encoding genes and heptaplex PCR to identify capsular serotypes K1, K2, K3, K5, K20, K54 and K57. Results The study found an overall phenotypic carbapenem resistance of 23.3% (53/227) and significantly higher genotypic resistance prevalence of 43.1% (98/227). Over all, the most prevalent gene was blaOXA-48-like (36.4%), followed by blaIMP-type (19.4%), blaVIM-type (17.1%), blaKPC-type (14.0%) and blaNDM-type (13.2%). blaVIM-type and blaOXA-48-like conferred phenotypic resistance in all isolates and 38.3% of isolates that harbored them respectively. Capsular multiplex PCR revealed that 46.7% (106/227) isolates were pathogenic and the predominantly prevalent pathotype was K5 (18.5%) followed by K20 (15.1%), K3 (7.1%), K2 (3.1%) and K1 (2.2%). Of the 106 capsular serotypes, 37 expressed phenotypic resistance; thus, 37 of the 53 carbapenem resistant K. pneumoniae were pathogenic. Conclusion The high prevalence of virulent and antibiotic resistant K. pneumoniae among clinical isolates obtained from the four tertiary hospital as revealed by this study pose a great threat to healthcare. Our findings underline the epidemiological and public health risks and implications of this pathogen.

scholarly journals Carbapenem Resistance Profiles of Pathogenic Escherichia coli in Uganda

2021 ◽  
Vol 2 (2) ◽  
pp. 63-73
Author(s):  
Kenneth Ssekatawa ◽  
Denis K. Byarugaba ◽  
Jesca L. Nakavuma ◽  
Charles D. Kato ◽  
Francis Ejobi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Carbapenem Resistance ◽  
Phylogenetic Group ◽  
Clinical Isolates ◽  
Phylogenetic Groups ◽  
Phenotypic Resistance ◽  
E Coli ◽  
Tract Infections

Escherichia coli has been implicated as one of the main etiological agents of diarrhea, urinary tract infections, meningitis and septicemia worldwide. The ability to cause diseases is potentiated by presence of virulence factors. The virulence factors influence the capacity of E. coli to infect and colonize different body systems. Thus, pathogenic E. coli are grouped into DEC strains that are mainly clustered in phylogenetic group B1 and A; ExPEC belonging to A, B2 and D. Coexistence of virulence and beta-lactamase encoding genes complicates treatment outcomes. Therefore, this study aimed at presenting the carbapenem resistance (CR) profiles among pathogenic E. coli. This was a retrospective cross-sectional study involving use of 421 archived E. coli clinical isolates collected in 2019 from four Uganda tertiary hospitals. The isolates were subjected to antibiotics sensitivity assays to determine phenotypic resistance. Four sets of multiplex PCR were performed to detect CR genes, DEC pathotypes virulence genes, ExPEC PAI and the E. coli phylogenetic groups. Antibiotic susceptibility revealed that all the 421 E. coli isolates used were MDR as they exhibited 100% resistance to more than one of the first-line antibiotics. The study registered phenotypic and genotypic CR prevalence of 22.8% and 33.0% respectively. The most predominant gene was blaOXA-48 with genotypic frequency of 33.0%, then blaVIM (21.0%), blaIMP (16.5%), blaKPC (14.8%) and blaNDM (14.8%). Spearman’s correlation revealed that presence of CR genes was highly associated with phenotypic resistance. Furthermore, of 421 MDR E. coli isolates, 19.7% harboured DEC virulence genes, where EPEC recorded significantly higher prevalence (10.8%) followed by S-ETEC (3.1%), STEC (2.9%), EIEC (2.0%) and L-ETEC (2.0%). Genetic analysis characterized 46.1% of the isolates as ExPEC and only PAI IV536 (33.0%) and PAI IICFT073 (13.1%) were detected. Phylogenetic group B2 was predominantly detected (41.1%), followed by A (30.2%), B1(21.6%), and D (7.1%). Furthermore, 38.6% and 23.1% of the DEC and ExPEC respectively expressed phenotypic resistance. Our results exhibited significant level of CR carriage among the MDR DEC and ExPEC clinical isolates belonging to phylogenetic groups B1 and B2 respectively. Virulence and CR genetic factors are mainly located on mobile elements. Thus, constitutes a great threat to the healthcare system as this promotes horizontal gene transfer.

scholarly journals Virulence and antimicrobial susceptibility of clinical and environmental strains of Aeromonas spp. from northeastern Brazil

2015 ◽  
Vol 61 (8) ◽  
pp. 597-601 ◽  
Author(s):  
Débora de Souza Collares Maia Castelo-Branco ◽  
Glaucia Morgana de Melo Guedes ◽  
Raimunda Sâmia Nogueira Brilhante ◽  
Marcos Fábio Gadelha Rocha ◽  
José Júlio Costa Sidrim ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Virulence Genes ◽  
Clinical Isolates ◽  
Northeastern Brazil ◽  
Pathogenic Potential ◽  
Detection Rates ◽  
Environmental Strain ◽  
Clinical Strains ◽  
Automated Method ◽  
Amoxicillin Clavulanate

The aims of the present study were to isolate and identify clinical and environmental strains of Aeromonas spp. by means of biochemical tests and the automated method VITEK 2 and to investigate the presence of the virulence genes cytotoxic enterotoxin (act), hemolysin (asa-1), and type III secretion system (ascV), and also the in vitro antimicrobial susceptibility of the strains. From the clinical isolates, 19 Aeromonas hydrophila, 3 Aeromonas veronii bv. sobria, and 1 Aeromonas caviae were identified, while from the environmental strains, 11 A. hydrophila, 22 A. veronii bv. sobria, 1 A. veronii bv. veronii, and 1 A. caviae were recovered. The gene act was detected in 69.5% of clinical isolates, asa-1 in 8.6%, and ascV in 34.7%. In the environmental strains, the detection rates were 51.4%, 45.7%, and 54.2% for the genes act, asa-1, and ascV, respectively. Resistance to amoxicillin–clavulanate and piperacillin–tazobactam was observed in 15 and 3 clinical strains, respectively, and resistance to ceftazidime, meropenem, imipenem, ciprofloxacin, and trimethoprim–sulfamethoxazole was observed in 1 strain for each drug. Resistance to amoxicillin–clavulanate and piperacillin–tazobactam was detected in 17 and 1 environmental strain, respectively. Higher resistance percentages were observed in clinical strains, but environmental strains also showed this phenomenon and presented a higher detection rate of virulence genes. Thus, it is important to monitor the antimicrobial susceptibility and pathogenic potential of the environmental isolates.

scholarly journals SuhB Is a Regulator of Multiple Virulence Genes and Essential for Pathogenesis of Pseudomonas aeruginosa

mBio ◽  
2013 ◽  
Vol 4 (6) ◽  
Author(s):  
Kewei Li ◽  
Chang Xu ◽  
Yongxin Jin ◽  
Ziyu Sun ◽  
Chang Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Regulatory Networks ◽  
Virulence Genes ◽  
Chronic Infections ◽  
Content Type ◽  
Factors Associated ◽  
Acute Infections

ABSTRACTDuring initial colonization and chronic infection, pathogenic bacteria encounter distinct host environments. Adjusting gene expression accordingly is essential for the pathogenesis.Pseudomonas aeruginosahas evolved complicated regulatory networks to regulate different sets of virulence factors to facilitate colonization and persistence. The type III secretion system (T3SS) and motility are associated with acute infections, while biofilm formation and the type VI secretion system (T6SS) are associated with chronic persistence. To identify novel regulatory genes required for pathogenesis, we screened aP. aeruginosatransposon (Tn) insertion library and foundsuhBto be an essential gene for the T3SS gene expression. The expression ofsuhBwas upregulated in a mouse acute lung infection model, and loss ofsuhBresulted in avirulence. Suppression of T3SS gene expression in thesuhBmutant is linked to a defective translation of the T3SS master regulator, ExsA. Further studies demonstrated thatsuhBmutation led to the upregulation of GacA and its downstream small RNAs, RsmY and RsmZ, triggering T6SS expression and biofilm formation while inhibiting the T3SS. Our results demonstrate that anin vivo-inducible gene,suhB, reciprocally regulates genes associated with acute and chronic infections and plays an essential role in the pathogenesis ofP. aeruginosa.IMPORTANCEA variety of bacterial pathogens, such asPseudomonas aeruginosa, cause acute and chronic infections in humans. During infections, pathogens produce different sets of virulence genes for colonization, tissue damage, and dissemination and for countering host immune responses. Complex regulatory networks control the delicate tuning of gene expression in response to host environments to enable the survival and growth of invading pathogens. Here we identifiedsuhBas a critical gene for the regulation of virulence factors inP. aeruginosa. The expression ofsuhBwas upregulated during acute infection in an animal model, and mutation ofsuhBrenderedP. aeruginosaavirulent. Moreover, we demonstrate that SuhB is required for the activation of virulence factors associated with acute infections while suppressing virulence factors associated with chronic infections. Our report provides new insights into the multilayered regulatory network of virulence genes inP. aeruginosa.

scholarly journals Combinations of putative virulence markers in typical and variant enteroaggregative Escherichia coli strains from children with and without diarrhoea

2002 ◽  
Vol 129 (1) ◽  
pp. 49-55 ◽  
Author(s):  
W. P. ELIAS ◽  
A. P. UBER ◽  
S. K. TOMITA ◽  
L. R. TRABULSI ◽  
T. A. T. GOMES
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Statistical Difference ◽  
Virulence Genes ◽  
Cultured Cells ◽  
Probe Sequence ◽  
Pathogenic Potential ◽  
Significant Statistical Difference ◽  
Virulence Markers ◽  
Aggregative Adherence

Enteroaggregative Escherichia coli (EAEC) is defined by the ability to produce aggregative adherence (AA) to cultured cells. We analysed 128 EAEC strains, isolated from children with and without diarrhoea, regarding the presence of 11 EAEC virulence genes. Seventy strains carried and 58 lacked the EAEC probe sequence; 17 probe positive and 31 probe negative strains showed variations in the AA pattern. All EAEC probe positive strains carried at least one EAEC marker; aspU (94.3%), irp2 (91.4%), and aggR (74.3%) were the most prevalent. Conversely, among the EAEC probe negative strains, 41.4% were devoid of any marker and astA predominated (44.8%). No significant statistical difference in the prevalence of any marker between cases and controls in both EAEC probe groups or AA variants was found. We suggest that the EAEC probe positive strains may have a higher pathogenic potential or alternatively, EAEC probe negative strains may harbour virulence factors as yet undescribed.

scholarly journals Detection of virulence genes in Escherichia coli strains isolated from diarrheic and healthy feces of dairy calves in Brazil

2012 ◽  
Vol 79 (2) ◽  
pp. 273-276 ◽  
Author(s):  
C. de Moura ◽  
M. Ludovico ◽  
G.F. Valadares ◽  
M.S.V. Gatti ◽  
D.S. Leite
Keyword(s):  
Virulence Factors ◽  
Virulence Genes ◽  
Vero Cells ◽  
Dairy Calves ◽  
Biological Assays ◽  
High Frequencies ◽  
E Coli ◽  
Factors Associated ◽  
Heat Stable ◽  
Diarrheic Calves

The aim of this work was to test 101 strains of E. coli for virulence factors associated with enterotoxigenic and enterohemorrhagic pathotypes of E. coli isolated from diarrheic and non-diarrheic calves. The virulence factors of E. coli Stx1 (Shiga toxin), Stx2, Ehly (Enterohemolysin), the eae gene, LT-II (heat-labile enterotoxin), STa (heat-stable toxin), and adhesins K99 and F41 were detected by PCR. Serogroups were determined by serological methods and Stx production was observed by biological assays in Vero cells. The frequency of the eae gene was higher in isolates from diarrheic calves (35/58, 60.3%) than in non-diarrheic calves (8/43, 18.6%; P < 0.001). The gene for Stx1 occurred at high frequencies in the diarrheic strains (24/58, 41.3%) as well as in non-diarrheic (19/43, 44.2%) ones and all strains that were Stx positive by PCR showed cytotoxicity in Vero cells. Stx2 was found in ten strains, Ehly in eight strains, and LT-II in only two strains. Twenty-eight strains were negative for all of the PCR assays, including for F41 and K99 adhesins. The serogroups O7, O23, O4, O8, O153 and O156 were observed most frequently. Our results show that strains of E. coli isolated from cattle have similar virulence factors genes to strains isolated from cases of diseases in humans and may be a source of potentially pathogenic STEC for humans.

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