Analysis of virulence and drug resistance characteristics of diarrheagenic Escherichia coli isolated from patients with infectious diarrhea in a hospital in Beijing / 临床检验杂志

Objective To investigate the virulence and drug resistance characteristics of diarrheagenic Escherichia coli isolated from patients with infectious diarrhea in our hospital.Methods The preliminary identification of microbes was carried out by the VITEK-MS microbial mass spectrometry detection system and virulence genes were detected by the multiplex real-time PCR.Five types of diarrhea-genic Escherichia coli(DEC)clinically isolated from patients with infectious diarrhea in our hospital were identified.The drug resist-ance characteristics of DEC strains were detected by the microbroth dilution and E-test.The drug-resistant molecular characteristics were analyzed by the next-generation sequencing and bioinformatics.The Fisher exact probability method was used for statistical analy-sis.Results The detection rate of DEC in our hospital was 11.9%,with enteroaggregative E.coli(EAEC)accounting for 37.5%,a-typical enteropathogenic Escherichia coli(EPEC)accounting for 34.38%,enterotoxigenic E.coli(ETEC)accounting for 25.0%,and enteroinvasive E.coli(EIEC)accounting for 3.12%.None of enterohemorrhagic E.coli(EHEC)strain was detected.The resistance rates of 32 DEC strains to ampicillin,tetracycline,and trimethoprim/sulfamethoxazole were 53.12%,43.75%,and 37.5%,respec-tively.ESBLs(+)strains accounted for 18.75%,and the detection rate of multidrug-resistant strains was 83.83%,significantly higher than that of ESBLs(-)strains(P=0.042).A total of 25 ST genotypes were obtained from 32 DEC strains.The dominant genotypes were ST10(4 strains,12.5%),followed by ST28(2 strains,6.25%),ST31(2 strains,6.25%),ST3153(2 strains,6.25%),and the other 21 genotypes(1 strain,3.13%).One carbapenem resistant strain carrying the blaNDM-1 gene was detected in EAEC.Conclu-sion Four virulence genes such as aggR,pic,astA,and eae,are more common in the DEC of patients with infectious diarrhea in our hospital,with EAEC and EPEC as the main subtypes.The genotypes are highly polymorphic,and multidrug-resistant strains have been detected.

Correlation of the emm genotyping and virulence genes with the isolation sites of Group A Streptococcus strains from children with impetigo / 中华实用儿科临床杂志

Objective:To investigate the correlation of the emm genotypes and virulence genes with the isolation sites of Group A Streptococcus (GAS). Methods:It was a retrospective study.The specimens were collected from children with impetigo in Beijing Children′s Hospital, Capital Medical University from 2006 to 2008 for GAS isolation and identification.A total of 24 GAS strains were isolated from 16 children with impetigo, among which 7 pairs of strains were isolated from the throat and skin of 7 children, and 1 pair of strains was isolated from the vulva and skin of one child, and the remaining 8 GAS strains were isolated from the skin pus samples of 8 children.Polymerase chain reaction was applied to detect the emm genotypes and 13 virulence genes ( speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa). The correlation of the emm genotypes and virulence genes with the isolation sites of GAS strains was analyzed. Results:In this study, four emm genotypes were detected, including emm1.0 (15/24), emm12.0 (4/24), emm22.0 (2/24) and emm160.0 (1/24), and one subtype emm12.19 (2/24) was detected as well.The carrying rates of 13 virulence genes speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were 58.3%, 100%, 91.7%, 100%, 50.0%, 12.5%, 54.2%, 66.7%, 16.7%, 25.0%, 12.5%, 100% and 91.7%, respectively.All strains carried 5 to 11 virulence genes and they all carried speB, speF and smeZ.There were significant differences in the carrying rate of speA and speJ among the strains with different emm genotypes (all P<0.05). There was no significant difference in the distribution of virulence genes between skin isolates and pharyngeal isolates, including the 5 pairs of strains carrying the emm1.0 genotype (all P>0.05). Conclusions:The distribution of virulence gene of GAS in children with impetigo is significantly correlated with the emm genotype, rather than the isolation site.

Research progress on pathogenicity and related virulence factors of Klebsiella oxytoca / 中华检验医学杂志

Klebsiella oxytoca is an important opportunistic pathogen which cause community or hospital-acquired infections in adults and children. The disease it most causes is antibiotic-associated hemorrhagic colitis (AAHC). It can also cause diseases such as urinary tract infections, pneumonia and bloodstream infections. The cytotoxins including Tilivalline and Tilimycin are important virulence factors for Klebsiella oxytoca, mainly causing AAHC. This article reviewed the progress of research on the prevalence, pathogenicity and mechanisms of K.oxytoca, hoping to improve the understanding of K.oxytoca and provide guidance on disease prevention and treatment.

Molecular differentiation of coagulase-positive staphylococcal isolates carrying mecA- and PVL-encoding genes among healthy males

Aims@#This study was aimed to monitor the asymptomatic carriage of coagulase-positive staphylococcal bacteria among university male students and detect the prevalence of virulence marker genes that encode methicillin resistance (mecA) and Panton-Valentine leukocidin (PVL) toxin among the isolates.@*Methodology and results@#Single nasal swaps were collected from 144 participating students who resided at four different locations within Al-Madinah city. A total of 112 Gram-positive staphylococcal isolates were recovered from the 144 participants (carriage rate of 77.8%). Coagulase-positive staphylococci were differentiated using duplex PCR amplification of the 16S rRNA and nuc genes and accounted for 30 isolates (carriage rate of 20.8%). These isolates were most prevalent in the northern and southern parts of Al-Madinah city, while the lowest numbers of isolates were detected in students of the eastern part. Coagulase-positive isolates were further phenotypically characterized for methicillin resistance by the disc diffusion method. Uniplex PCR assays were conducted to screen for mecA- and PVL toxin-encoding genes. The mecA gene was amplified from all 15 (50%) methicillin-resistant coagulase-positive isolates, while the PVL toxin-encoding gene was detected in 19 isolates (63.3%), 10 (33.3%) of which contained the mecA gene. Lastly, PCR amplification of the NRPS gene from coagulase-positive isolates revealed the absence of Staphylococcus argenteus, the recently discovered genetically divergent lineage of Staphylococcus aureus.@*Conclusion, significance and impact of study@#An elevated prevalence of coagulase-positive isolates harboring mecA and PVL virulence genes was observed compared with previous investigations. This poses a potential threat if they spread among the population, resulting in outbreaks of community-acquired infections.

Distribution of virulence genes in clinical isolates of hospital-associated and community-associated methicillin-susceptible Staphylococcus aureus from Terengganu, Malaysia

@#Staphylococcus aureus is a common bacterial pathogen known to cause various kinds of infections due to its repertoire of virulence factors. This study aimed to investigate the distribution of 19 types of virulence genes among clinical isolates of methicillin-susceptible S. aureus (MSSA) using the polymerase chain reaction. A total of 109 MSSA isolates, i.e., 63 hospital-associated (HA) and 46 community-associated (CA) were collected from Hospital Sultanah Nur Zahirah, the main tertiary hospital in Terengganu, Malaysia, from July 2016 to June 2017. The most frequent virulence genes detected were hla (78.9%, n=86) and hld (78.0%, n=85) encoding hemolysins, lukED (56.9%, n=62) encoding leukotoxin ED, followed by seb (26.6%, n=29) and sea (24.8%, n=27) encoding enterotoxins. Among 34 (31.2%) isolates carrying six or more virulence genes, only five were multidrug resistant (MDR) while the remaining isolates were susceptible. Significant associations were discovered between the hld gene with CA-MSSA (p=0.016) and the seo gene with HA-MSSA (p=0.023). However, there is no significant association between virulence genes among the different types of infection. The clinical MSSA isolates in Terengganu showed high prevalence and high diversity of virulence gene carriage.

Molecular characterization of Aeromonas hydrophila isolates from diseased fishes in district Kasur, Punjab, Pakistan / Caracterização molecular de isolados de Aeromonas hydrophila de peixes doentes no distrito de Kasur, Punjab, Paquistão

Abstract Pakistan is an agricultural country and fisheries play a very important role in the economic development of the country. Different diseases are prevalent in Pakistani fish but information related to the causative agents is not well-known. Keeping in view the significance of bacterial pathogens as the causative agents of multiple fish diseases, the present study was conducted for identification, characterization and analysis of virulence genes of Aeromonas spp. isolated from diseased fishes. A total of fifty fish samples having multiple clinical indications were collected from different fish farms of district Kasur, Punjab Pakistan. For isolation of Aeromonas spp. samples were enriched and inoculated on Aeromonas isolation medium. Isolates were identified and characterized by different biochemical tests, Analytical Profile Index (API) 20E kit and Polymerase Chain Reaction (PCR) assays. All isolates were screened for three putative virulence genes including aerolysin (aer), haemolysin (hyl) and heat labile cytotonic enterotoxin (alt). Seven isolates of Aeromonas (A.) hydrophila were retrieved and identified based on API 20E. These isolates were further confirmed as A. hydrophila on the basis of PCR assays. Three isolates were detected positive for the presence of virulence genes (alt and hyl). Whereas aerolysin (aer) gene was not present in any of A. hydrophila isolates. The present study confirmed A. hydrophila as the causative agent of epizootic ulcerative syndrome and motile Aeromonas septicemia in fish farms of district Kasur, Punjab Pakistan. Moreover, detection of two virulence genes (alt and hyl) in A. hydrophila isolates is a threat for fish consumers of study area.

Resumo O Paquistão é um país agrícola, onde a pesca desempenha um papel muito importante para o desenvolvimento econômico. Diferentes doenças são prevalentes em peixes do Paquistão, mas as informações relacionadas aos agentes causadores não são bem conhecidas. Tendo em vista a importância dos patógenos bacterianos como agentes causadores de múltiplas doenças em peixes, o presente estudo foi conduzido para identificação, caracterização e análise de genes de virulência de isolados de Aeromonas spp. de peixes doentes. Foram coletadas 50 amostras de peixes com múltiplas indicações clínicas em diferentes fazendas do distrito de Kasur, Punjab, Paquistão. Para isolar Aeromonas spp., as amostras foram enriquecidas e inoculadas em meio de isolamento. Os isolados foram identificados e caracterizados por diferentes testes bioquímicos, kit Analytical Profile Index (API) 20E, e ensaios de reação em cadeia da polimerase (PCR). Todos os isolados foram selecionados para três genes de virulência putativos, incluindo aerolisina (aer), hemolisina (hyl) e enterotoxina citotônica termolábil (alt). Sete isolados de Aeromonas hydrophila foram recuperados e identificados com base no API 20E. Esses isolados foram posteriormente confirmados como A. hydrophila de acordo com ensaios de PCR. Três isolados indicaram a presença de genes de virulência (alt e hyl), enquanto o gene aerolisina (aer) não esteve presente em nenhum dos isolados de A. hydrophila. O presente estudo confirmou A. hydrophila como o agente causador da síndrome ulcerativa epizoótica e septicemia móvel por Aeromonas em fazendas de peixes, no distrito de Kasur, Punjab, Paquistão. Além disso, a detecção de dois genes de virulência (alt e hyl) em isolados de A. hydrophila é uma ameaça para os consumidores de peixes da área de estudo.

Caries prevention mechanism of the Xinjiang Mori Cortex based on network pharmacology and its effect on the main cariogenic bacteria / 口腔疾病防治

Objective@#To investigate the potential caries prevention mechanism of the Xinjiang Mori cortex and to analyze its effect on the main cariogenic bacteria.@*Methods@#The active components of the Xinjiang Mori cortex and the main targets were predicted and screened using the TCMSP database. The GeneCards, DisGENET and TTD databases were used to obtain caries-related targets. The common targets were derived, and core genes were screened. The enrichment analysis was performed using the DAVID data platform. Molecular docking was performed using AutoDock software. In in vitro antibacterial experiments, first, the 50% minimum inhibitory concentration (MIC50) and the minimum bactericidal concentration (MBC) of the Xinjiang Mori Cortex extract against Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus were determined and the growth curves were measured. The effects of the Xinjiang Mori Cortex extract on acid production, polysaccharide production and adhesion ability of Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus in the planktonic state were determined. The 50% minimum biofilm inhibition concentration (MBIC50) and 50% minimum biofilm reduction concentration (MBRC50) were determined by crystal violet staining, and biofilm morphology was visualized using scanning electron microscopy (SEM).@*Results@#The main active components of the Xinjiang Mori cortex included quercetin, kaempferol, and β-sitosterol. Tumor necrosis factor (TNF), interleukin-6 (IL-6), and interleukin-1beta (IL-1β) could be the most important targets of the Xinjiang Mori cortex for the prevention of dental caries. The enrichment analysis results showed that Mori cortex extract may have effects on the AGE-RAGE signaling pathway, IL-17 signaling pathway, and TNF signaling pathway. The antibacterial experiment results showed that the MIC50 values of Xinjiang Mori Cortex extract against Streptococcus mutans, Streptococcus sanguis and Actinomyces viscosus were 0.5, 0.5 and 0.25 mg/mL, respectively, and the MBCs were 4.0, 2.0 and 1.0 mg/mL, respectively. The inhibitory effect of Xinjiang Mori Cortex extract on the acid production, polysaccharide production and adhesion ability of three major cariogenic bacteria in the planktonic state was stronger than that of the control group, and the differences were statistically significant (P<0.05). The MBIC50 was 1.0, 1.0, and 0.5 mg/mL, and the MBRC50 was 4.0, 4.0, and 2.0 mg/mL. SEM observation showed that the amount of biofilm formation decreased with the drug concentration compared with the control group.@*Conclusion@#Xinjiang Mori cortex extract can prevent caries through quercetin, kaempferol, and β-sitosterol active ingredients, TNF、IL-6、IL-1β key targets and multiple pathways and inhibit the growth, acid production, polysaccharide production, and adhesion ability of three major cariogenic bacteria in the planktonic state and has some inhibitory effect on corticogenic biofilm formation.

Differential expression of virulence factors in clinical isolates of Candida parapsilosis / 中国感染控制杂志

Objective To compare the differences in virulence-related factor aspartate protease,biofilm formation,and gene expression among clinical isolates of Candida parapsilosis(C.parapsilosis).Methods Gene sequencing and microsatellite typing(MT)method were adopted to identify C.parapsilosis isolated from patients with clinical fungal infection.The production of secreted aspartate protease and biofilm formation ability of each strain were de-tected,and the expression of biofilm formation related-genes BCR1,EFG1,and HWP1,as well as aspartate prote-ase virulence genes SAPP1,SAPP2,SAPP3 were compared among the strains.Results A total of 8 clinically iso-lated C.parapsilosis strains were collected,all of which were identified as genotype Ⅰ.Based on microsatellite ty-ping results,8 clinical strains were divided into 4 microsatellite types.G1,G2,and G3 strains isolated from the urine,peripherally inserted central catheters(PICC),and blood of patient A were of different subtypes.J1,J2,J3,J4,and J5 strains were of the same type,and isolated from blood specimens of patient B at different periods.All 8 clinical strains could form biofilm,and their biofilm formation ability was higher than that of the standard strain of C.parapsilosis(ATCC 22019).G1,G3 and J5 strains had strong biofilm formation ability,J1,J2,J3,and J4 strains had moderate biofilm formation ability,and G2 strain had weak biofilm formation ability.All of the eight clinical isolates secreted aspartate protease,and their in vitro expression levels of the enzyme were higher than that of the standard strain(ATCC 22019).G3,G1,and G2 strains showed low,moderate,and high in vitro enzyme expression respectively,with statistical differences(all P＜0.05).Enzyme expressed moderately in J1 and J5 strains,and highly in J2,J3,and J4 strains.Difference between moderate and high expressions was statistically significant(P＜0.05).The expression levels of biofilm formation genes BCR1,EFG1,and HWP1 in various strains isolated from patients A and B increased.In strains isolated from patient A,the expression level of EFG1 gene in G1 strain was higher than that in G2 strain(P＜0.05).There was no statistically significant difference in BCR1,EFG1,and HWP1 gene expression levels among strains isolated from patient B.The expression levels of as-partate protein genes(SAPP1,SAPP2,and SAPP3)in various strains isolated from patients A and B increased.The expression levels of SAPP1 and SAPP2 in strain G1 were higher than those in G2 and G3(both P＜0.05).There was no statistically significant difference in the expression levels of SAPP1,SAPP2,and SAPP3 genes in strains from patient B.Conclusion Clinical isolates of C.parapsilosis have higher biofilm formation and aspartate protease production abilities than standard strain.The expression of virulence factors varies among strains isolated from different specimens,while there is no significant difference in the expression of virulence factors among strains isolated at different periods.Patients may have been infected with different MT types of C.parapsilosis in multiple sites during the same period.

Research progress on distribution characteristics and pathogenesis of periapical microorganisms in chronic periapical periodontitis / 中国基层医药

Periapical periodontitis arises from the interaction between microbial factors and the inflammatory response of the host's periapical tissues. In this process, bacteria and their byproducts serve as the primary drivers for the initiation, progression, and spread of the disease. Pulp infections and periapical lesions are primarily dominated by gram-negative bacteria. The endotoxin lipopolysaccharide component of these bacteria plays a crucial role in pulp infection, triggering clinical symptoms, inflammatory reactions, and bone tissue resorption. Similarly, lipoteichoic acid and lipopolysaccharide from gram-positive bacteria exhibit similar pathogenic characteristics, causing damage to pulp and periapical tissues. The aim of this review is to delve deeper into the distribution patterns and pathogenesis of periapical microorganisms in chronic periapical periodontitis.

Virulence determinants and genetic diversity of foodborne Yersinia enterocolitica isolated from Wenzhou / 中国人兽共患病学报

The aim of this study was to investigate the virulence determinants and genetic diversity of foodborne Yersinia enterocolitica from Wenzhou.A total of 71 strains of Yersinia enterocolitica were isolated from food and foodborne diarrhea ca-ses in Wenzhou,and their biotypes,serotypes,and drug resistance were analyzed.On the basis of whole genome sequencing,we assessed virulence gene profiles,and performed multilocus sequence typing(MLST)and core gene multilocus sequence typ-ing(cgMLST).A total of 94.4％(67/71)of isolates belonged to biotype 1A,and the highest proportion had serotype lA/O∶5(29.6％,21/71).The sensitivity rates of the isolates to 14 antibiotics exceeded 95.8％.A total of 16 categories and 126 viru-lence genes were identified,with two strains carrying the pYV plasmid and chromosome-related virulence genes.ST3(31.6％,12/38)was the most widespread MLST type,and cgMLST analysis revealed no dense clusters of genotypes except for strains sharing the same ST.In conclusion,pathogenic strains were identified from foodborne Yersinia enterocolitica in Wenzhou and were found to exhibit high genetic polymorphism.Enhanced regulatory supervision is essential to prevent the outbreak of food-borne diseases caused by Yersinia enterocolitica.

Molecular characterization of Aeromonas hydrophila isolates from diseased fishes in district Kasur, Punjab, Pakistan

Abstract Pakistan is an agricultural country and fisheries play a very important role in the economic development of the country. Different diseases are prevalent in Pakistani fish but information related to the causative agents is not well-known. Keeping in view the significance of bacterial pathogens as the causative agents of multiple fish diseases, the present study was conducted for identification, characterization and analysis of virulence genes of Aeromonas spp. isolated from diseased fishes. A total of fifty fish samples having multiple clinical indications were collected from different fish farms of district Kasur, Punjab Pakistan. For isolation of Aeromonas spp. samples were enriched and inoculated on Aeromonas isolation medium. Isolates were identified and characterized by different biochemical tests, Analytical Profile Index (API) 20E kit and Polymerase Chain Reaction (PCR) assays. All isolates were screened for three putative virulence genes including aerolysin (aer), haemolysin (hyl) and heat labile cytotonic enterotoxin (alt). Seven isolates of Aeromonas (A.) hydrophila were retrieved and identified based on API 20E. These isolates were further confirmed as A. hydrophila on the basis of PCR assays. Three isolates were detected positive for the presence of virulence genes (alt and hyl). Whereas aerolysin (aer) gene was not present in any of A. hydrophila isolates. The present study confirmed A. hydrophila as the causative agent of epizootic ulcerative syndrome and motile Aeromonas septicemia in fish farms of district Kasur, Punjab Pakistan. Moreover, detection of two virulence genes (alt and hyl) in A. hydrophila isolates is a threat for fish consumers of study area.

Resumo O Paquistão é um país agrícola, onde a pesca desempenha um papel muito importante para o desenvolvimento econômico. Diferentes doenças são prevalentes em peixes do Paquistão, mas as informações relacionadas aos agentes causadores não são bem conhecidas. Tendo em vista a importância dos patógenos bacterianos como agentes causadores de múltiplas doenças em peixes, o presente estudo foi conduzido para identificação, caracterização e análise de genes de virulência de isolados de Aeromonas spp. de peixes doentes. Foram coletadas 50 amostras de peixes com múltiplas indicações clínicas em diferentes fazendas do distrito de Kasur, Punjab, Paquistão. Para isolar Aeromonas spp., as amostras foram enriquecidas e inoculadas em meio de isolamento. Os isolados foram identificados e caracterizados por diferentes testes bioquímicos, kit Analytical Profile Index (API) 20E, e ensaios de reação em cadeia da polimerase (PCR). Todos os isolados foram selecionados para três genes de virulência putativos, incluindo aerolisina (aer), hemolisina (hyl) e enterotoxina citotônica termolábil (alt). Sete isolados de Aeromonas hydrophila foram recuperados e identificados com base no API 20E. Esses isolados foram posteriormente confirmados como A. hydrophila de acordo com ensaios de PCR. Três isolados indicaram a presença de genes de virulência (alt e hyl), enquanto o gene aerolisina (aer) não esteve presente em nenhum dos isolados de A. hydrophila. O presente estudo confirmou A. hydrophila como o agente causador da síndrome ulcerativa epizoótica e septicemia móvel por Aeromonas em fazendas de peixes, no distrito de Kasur, Punjab, Paquistão. Além disso, a detecção de dois genes de virulência (alt e hyl) em isolados de A. hydrophila é uma ameaça para os consumidores de peixes da área de estudo.

Efeito de extratos vegetais de Hamamelis virginiana, Persea americana, Cynara scolymus L e Stryphnodendron barbatiman Msobre a expressão fenotípica dos fatores de virulência em biofilmes de Candida albicans / Effect of Hamamelis virginiana, Persea americana, Cynara scolymus L and Stryphnodendron barbatiman M plant extracts on the phenotypic expression of virulence factors in biofilms of the Candida albicans

Objetivo: Analisar a expressão fenotípica de fatores de virulência em biofilmes de Candida albicans frente a extratos glicólicos de plantas. Material e Métodos: Os biofilmes de Candida albicans (ATCC 18804) obtidos a partir de incubação de 48 horas foram expostos por 5 minutos e 24 horas a diferentes concentrações de extratos glicólicos de Hamamelis virginiana e Persea americana, Cynara scolymus L e Stryphnodendron barbatiman M, a fim de verificar a ação antifúngica da proteinase, fosfolipase e hemolisina. Resultados: Todos os extratos foram eficazes na redução do biofilme. Em contato por 5 minutos. os extratos reduziram 50% do biofilme. Após 24 horas. o extrato de Persea americana apresentou o biofilme em 90%, seguido de Cynara scolymus, que o interrompeu em 85%. Houve mudança na intensidade da proteinase após 5 minutos e 24 horas, com uma atividade enzimática média de 0,69 em comparação com o controle de 0,49. Cynara scolymus foi o extrato com maior concentração média de 100 mg/ml; a intensidade da fosfolipase foi alterada com Stryphnodendron barbatiman sendo mais efetivo em 24 horas em relação ao controle (p< 0,0001). A secreção de hemolisina foi modificada por Hamamelis virginiana (12,5 mg/ml) após 5 minutos de exposição e em 24 horas. todos os extratos foram capazes de causar alterações na secreção. Conclusão: Os extratos testados apresentam potencial antifúngico em biofilmes de Candida albicans, implicando em redução significativa dos fatores de virulência. Assim, estes podem ser indicados como uma ferramenta terapêutica alternativa para reduzir a morbidade dessas infecções, já que em ambos os tempos de exposição investigados, eles foram capazes de reduzir a secreção enzimática do fungo (AU)

Objective: Analyze the phenotypic expression of virulence factors in Candida albicans biofilms against plant glycolicextracts. Material and Methods: The biofilms of Candida albicans (ATCC 18804) obtained from incubation for 48 hours were exposed for 5 minutes and 24 hours to different concentrations of glycolic extracts of Hamamelis virginiana and Persea americana, Cynara scolymus L and Stryphnodendron barbatiman M, in order to verify the antifungal activity of the proteinase, phospholipase and hemolysin. Results: All extracts were effective in reducing biofilm. In contact for 5 minutes. the extracts reduced 50% of the biofilm. After 24 hours, the Persea americanaextract showed the biofilm at 90%, followed by Cynara scolymus, which interrupted it at 85%, There was a change in proteinase intensity after 5 minutes and 24 hours. with an average enzymatic activity of 0.69 compared to the control of 0.49. Cynara scolymus was the extract with the highest mean concentration of 100 mg/ml; the phospholipase intensity was changed with Stryphnodendron barbatiman being more effective in 24 hours compared to the control (p< 0.0001). The hemolysin secretion was modified by Hamamelis virginiana (12.5 mg/ml) after 5 minutes of exposure, and in 24 hours. all extracts were capable to cause changes in secretion. Conclusion: The tested extracts have antifungal potential in Candida albicans biofilms, implying a significant reduction in virulence factors. Thus, these can be indicated as an alternative therapeutic tool to reduce the morbidity of these infections, as in both investigated exposure times. they were able to reduce theenzymatic secretion of the fungus (AU)

Murciélagos como vectores de enfermedades virales e impacto en la salud humana

Introducción: Los murciélagos se destacan por ser los únicos mamíferos voladores, con alrededor de 1 400 especies que cumplen un rol fundamental como controladores de plagas y polinizadores de plantas nocturnas. Sin embargo, su influencia sobre la salud humana se ha evidenciado cada vez más, en particular después del surgimiento de brotes epidémicos de enfermedades virales asociadas a estos mamíferos. Objetivo: Analizar la influencia de los murciélagos en la salud humana, centrándose en su papel como portadores de enfermedades virales y su potencial como reservorios y vectores de enfermedades. Métodos: Se realizó una revisión bibliográfica de la literatura utilizando descriptores MeSH y términos como: Animals, Wild Chiroptera, Virus Diseases, Zoonoses, Disease Vectors, Disease Reservoirs, Public Health, bats, Communicable Disease Control, Disease Outbreaks, Prevention and Control. Se revisaron 1 442 artículos en bases de datos y documentos oficiales, se seleccionaron las fuentes relevantes con Mendeley Desktop 1.19.4. y se obtuvieron al final 47 artículos. Resultados: Existen varias especies de murciélagos que pueden afectar la salud del ser humano y que albergan en especial virus de las familias Filoviridae, Coronaviridae y Paramixoviridae. Los murciélagos se consideran incubadoras óptimas para la propagación de virus debido a su sistema inmune único que lo hace resistente a estos agentes infecciosos. Conclusiones: La vigilancia y monitoreo de los murciélagos, junto con acciones de educación pública y una gestión adecuada de sus hábitats, son fundamentales para la detección temprana y prevención de la transmisión de nuevos virus de estos mamíferos a los humanos.

Introduction: Bats are the only flight mammals, with around 1,400 species playing critical roles as pest controllers and nocturnal plant pollinators. However, its impact on human health has become increasingly evident, especially after the appearance of epidemic outbreaks of viral diseases related to these mammals. Objetive: To analyze the influence of bats on human health, focusing on their role as carriers of viral diseases and their potential as reservoirs and vectors of diseases. Methods: A literature bibliographical review was conducted using MeSH descriptors and keywords such as: Animals, Wild Chiroptera, Virus Diseases, Zoonosis, Disease Vectors, Disease Reservoirs, Public Health, bats, Communicable Disease Control, Disease Outbreaks, Prevention and Control. 1442 articles in databases and official documents were reviewed, selecting the relevant sources with Mendeley Desktop 1.19.4., obtaining 47 articles at the end. Results: There are several species of bats that can affect human health and that mainly harbor viruses from the Filoviridae families, Coronaviridae and Paramyxoviridae. Bats are considered optimal incubators for the spread of the virus due to their unique immune system that makes them particularly resistant to these infectious agents. Conclusions: Surveillance and monitoring of bats, together with public education actions and proper management of their habitats, are essential for early detection and prevention of transmission of new viruses from these mammals to humans.

Diminuição da expressão do microRNA-629 em amostras de câncer gástrico potencializada pelo marcador de virulências do H. pylori, gene cagA / Decreased expression of microrna-629 in gastric cancer samples potentiated by the virulence marker of h. pylori, caga gene

ABSTRACT Background: Helicobacter pylori (H. pylori) is a gram-negative bacterium associated with the etiology of several gastrointestinal tract pathologies, and cagA-positive (cagA+) strains are found in populations with gastric ulcers and precancerous lesions, inducing pro-inflammatory responses. The development of neoplasms is related to microRNA (miRNA) dysregulation, indicating highly expressed miRNA-629. The article aims to correlate the expression level of miRNA-629 with the presence of H. pylori and the pathogenicity marker cagA. Methods: 203 gastric biopsy samples were evaluated from individuals with normal gastric tissue (n=60), gastritis (n=96), and gastric cancer (n=47) of both genders and over 18 years old. The samples were subdivided according to the presence or absence of H. pylori, detected by polymerase chain reaction (PCR). RNA was extracted using a commercial kit and quantified. Complementary DNA (cDNA) was synthesized using commercial kits, and the relative expression was calculated using the 2-ΔΔCt method. Results: Individuals infected with H. pylori are nine times more likely to develop gastric cancer. Cancer patients appeared to have decreased expression of miRNA-629; however, the presence of the bacterium would not influence this reduction. Individuals in the cancer group showed lower miRNA-629 expression when cagA+; however, in the control group, the expression was higher when cagA+. Conclusion: H. pylori is a factor involved in the etiology and progression of gastric diseases. Reduction in miRNA-629 expression in cancer patients occurs independent of the presence of the bacterium, but when the cagA pathogenicity marker is present, it induces changes in the gene expression of the respective miRNA.

RESUMO Contexto: Helicobacter pylori (H. pylori) é uma bactéria gram-negativa associada à etiologia de várias patologias do trato gastrointestinal, e cepas positivas para cagA (cagA+) são encontradas em populações com úlceras gástricas e lesões pré-cancerígenas, induzindo respostas pró-inflamatórias. O desenvolvimento de neoplasias está relacionado à desregulação do microRNA (miRNA), indicando miRNA-629 altamente expresso. O artigo tem como objetivo correlacionar o nível de expressão do miRNA-629 com a presença de H. pylori e o marcador de patogenicidade cagA. Métodos: Foram avaliadas 203 amostras de biópsia gástrica de indivíduos com tecido gástrico normal (n=60), gastrite (n=96) e câncer gástrico (n=47) de ambos os sexos e com mais de 18 anos. As amostras foram subdivididas de acordo com a presença ou ausência de H. pylori, detectado por reação em cadeia da polimerase (PCR). O RNA foi extraído usando um kit comercial e quantificado. O DNA complementar (cDNA) foi sintetizado usando kits comerciais, e a expressão relativa foi calculada usando o método 2-ΔΔCt. Resultados: Indivíduos infectados com H. pylori têm nove vezes mais chances de desenvolver câncer gástrico. Pacientes com câncer parecem ter diminuição da expressão do miRNA-629; no entanto, a presença da bactéria não influenciaria essa redução. Indivíduos no grupo do câncer apresentaram menor expressão do miRNA-629 quando cagA+; no entanto, no grupo controle, a expressão foi maior quando cagA+. Conclusão: H. pylori é um fator envolvido na etiologia e progressão das doenças gástricas. A redução na expressão do miRNA-629 em pacientes com câncer ocorre independentemente da presença da bactéria, mas quando o marcador de patogenicidade cagA está presente, induz mudanças na expressão gênica do respectivo miRNA.

Acinetobacter baumannii as an oro-dental pathogen: a red alert!!

Abstract Objectives This review highlights the existence and association of Acinetobacter baumannii with the oro-dental diseases, transforming this systemic pathogen into an oral pathogen. The review also hypothesizes possible reasons for the categorization of this pathogen as code blue due to its stealthy entry into the oral cavity. Methodology Study data were retrieved from various search engines reporting specifically on the association of A. baumannii in dental diseases and tray set-ups. Articles were also examined regarding obtained outcomes on A. baumannii biofilm formation, iron acquisitions, magnitude of antimicrobial resistance, and its role in the oral cancers. Results A. baumannii is associated with the oro-dental diseases and various virulence factors attribute for the establishment and progression of oro-mucosal infections. Its presence in the oral cavity is frequent in oral microbiomes, conditions of impaired host immunity, age related illnesses, and hospitalized individuals. Many sources also contribute for its prevalence in the dental health care environment and the presence of drug resistant traits is also observed. Its association with oral cancers and oral squamous cell carcinoma is also evident. Conclusions The review calls for awareness on the emergence of A. baumannii in dental clinics and for the need for educational programs to monitor and control the sudden outbreaks of such virulent and resistant traits in the dental health care settings.

Interação de cepas de Lactobacillus crispatus com Streptococcus agalactiae em culturas celulares mimetizando o ambiente vaginal / Interaction between Lactobacillus crispatus and Streptococcus agalactiae strains in cell cultures mimicking the vaginal environment

A microbiota vaginal é dominada pelo gênero Lactobacillus, mantendo um pH ácido crucial para a saúde. Alterações hormonais e a menopausa podem impactar essa microbiota. Estreptococos do Grupo B (EGB) são associados a infecções neonatais e podem colonizar a microbiota vaginal. A interação entre Lactobacillus e EGB é complexa, com resultados conflitantes em estudos in vitro e in vivo. O uso de probióticos contendo Lactobacillus pode ter benefícios, como alterar a positividade para EGB em um grupo que recebeu o tratamento. Contudo a replicabilidade deste resultado é limitada, e os mecanismos envolvidos nessa interação ainda são pouco elucidados. Portanto o objetivo desse estudo foi caracterizar cepas de EGB, avaliar sua interação com L. crispatus em diversas condições. Neste estudo foram selecionadas seis cepas, pertencentes aos sorotipos Ia, II, III e V. Essas cepas foram caracterizadas de acordo com o sorotipo capsular, presença de genes de virulência (hialuronidase, ß-citolisina/hemolisina, e ilhas de pili 1, 2a e 2b), resistência a antimicrobianos (penicilina, cefepima, vancomicina, eritromicina e clindamicina), curva de crescimento, Restriction Fragment Length Polymorphism (RFLP) e Multi-Locus Sequence Typing (MLST). O resultado de MLST identificou os sequence types ST1, ST23 ST28 e ST182, e os clonal complexes CC1, CC19 e CC23. Cepas possuem a maior parte dos genes de virulência testados. Somente uma cepa apresentou alguma resistência, no caso à eritromicina e clindamicina. Resultados que estão de acordo com a literatura como os principais descritos em isolados clínicos. Os ensaios de interação realizados foram: crescimento em co-cultura, formação de biofilme, ensaios de adesão e exclusão em cultura celular e por fim, análise do perfil proteico. Alguns efeitos de L. crispatus no EGB observados foram aumento na formação de biofilme de EGB e diminuição da sua proliferação quando em co-cultura. Contudo esses resultados variaram de acordo com a cepa de EGB. Nos ensaios de competição em cultura celular, a presença de L. crispatus levou à diminuição da adesão em uma cepa pertencente ao sorotipo III, e aumento de adesão em uma cepa pertencente ao sorotipo V. Quando a cultura de células recebeu tratamento prévio de L. crispatus, nos ensaios de exclusão, houve menor adesão de EGB. Contudo todos os efeitos observados são cepa-dependente; não foram encontradas associações entre o comportamento das cepas e seu sorotipo capsular ou fenótipo MLST. Estudos futuros podem elucidar as respostas ativadas na presença de microrganismos comensais

The vaginal microbiota is dominated by the genus Lactobacillus, which helps to maintain a crucial acidic pH for health. Hormonal changes and menopause can impact this microbiota. Group B Streptococcus (GBS) are associated with neonatal infections and can colonize the vaginal microbiota. The interaction between Lactobacillus and GBS is complex, with conflicting results in in vitro and in vivo studies. The use of probiotics containing Lactobacillus may have benefits, such as altering GBS positivity in a treated group. However, the replicability of this result is limited, and the mechanisms involved in this interaction are still poorly understood. The use of probiotics containing Lactobacillus may have some benefits, but further research is needed. These strains were characterized based on capsular serotype, presence of virulence genes (hyaluronidase, ß-cytolysin/hemolysin, and pili islands 1, 2a, and 2b), antimicrobial resistance (penicillin, cefepime, vancomycin, erythromycin, and clindamycin), growth curve, Restriction Fragment Length Polymorphism (RFLP), and Multi-Locus Sequence Typing (MLST) Therefore, the aim of this study was to characterize GBS strains, evaluate their interaction with L. crispatus under various conditions. Six strains were selected for this study, belonging to serotypes Ia, II, III, and V. MLST results identified sequence types ST1, ST23, ST28, and ST182, and clonal complexes CC1, CC19, and CC23. Most strains possessed the tested virulence genes, with only one strain showing resistance to erythromycin and clindamycin. These results are in line with the literature. Interaction assays included co-culture growth, biofilm formation, adhesion and exclusion assays in cell culture, and, finally, protein profile analysis. Some observed effects of L. crispatus on GBS included an increase in GBS biofilm formation and a decrease in GBS proliferation during co-culture. However, these results varied according to the GBS strain. GBS interaction with L. crispatus resulted in increased biofilm formation and decreased proliferation in co-culture. In cell culture competition assays, the presence of L. crispatus led to decreased adhesion in one GBS strain belonging to serotype III and increased adhesion in one strain belonging to serotype V. When cell culture received pre-treatment with L. crispatus, exclusion assays showed lower GBS adhesion. However, all observed effects are strain-dependent; no associations were found between strain behavior and capsular serotype or MLST phenotype. Future studies may elucidate the responses activated in the presence of commensal microorganisms

Emerging infection: streptococcal toxic shock-like syndrome caused by group B Streptococcus (GBS), Streptococcus agalactiae

ABSTRACT Streptococcus agalactiae or Group B Streptococcus (GBS) infections are commonly associated with infections in neonates and pregnant women. However, there has been a rising incidence in nonpregnant adults. The risk of GBS infection in nonpregnant adults is increased for patients of advanced age and those with underlying medical conditions such as diabetes mellitus and cancer. We present a 77-year-old female with type-2 diabetes mellitus, hypertension, and bilateral foot ulcers that presented in probable septic shock with necrotic foot ulcers and necrotizing fasciitis and underwent bilateral lower limb amputations. The patient fulfilled the Streptococcal Toxic Shock Syndrome (STSS) criteria as defined by The Working Group on Severe Streptococcal Infections. These criteria were created for group A Streptococcus (Streptococcus pyogenes). Our patient fulfilled the Working Group's criteria, except that the blood culture was positive for group B Streptococcus (Streptococcus agalactiae). Numerous studies demonstrate the importance of early detection and antibiotic treatment for GBS infections in general and early surgical management for necrotizing soft tissue infections (NSTIs) such as necrotizing fasciitis.

Assessing proteases and enzymes of the trypanothione system in subpopulations of Leishmania (Viannia) braziliensis Thor strain during macrophage infection

BACKGROUND Leishmania (Viannia) braziliensis Thor strain exhibits a heterogeneous composition comprised of subpopulations with varying levels of infectivity. Clonal subpopulations were previously obtained from the strain Thor by sorting single-parasites and proceeding cultivation. The subpopulations used in this study are named Thor03, Thor 10 and Thor22. OBJECTIVES Phenotypic characteristics of the parasite, specially focusing on virulence factors and resistance to the antimicrobial mechanisms of macrophages, were investigate in these subpopulations. METHODS Cellular and molecular biology, as well as biochemistry approaches were applied to obtain the data analysed in this study. FINDINGS Relative quantification of gene expression was measured for calpain, cysteine protease B (CPB), and subtilisin proteases but no significant differences in these genes' expression among subpopulations was observed. However, subtilisin and CPB proteins were assessed as more abundant in Thor03 by fluorescence-labelled flow cytometry technique. Western Blotting assays, as semi-quantitative analysis in gel, showed higher concentrations of subtilisin (110 to 50 kDa) and CPB (40 to 18 kDa) in extract of intracellular amastigotes from subpopulations Thor03 and Thor10 and calpain (60 to 25 kDa) showed no significant differences among subpopulations. Complementary, higher trypanothione reductase activity was observed in Thor10 intracellular amastigotes and assays of susceptibility to hydrogen peroxide-inducing agents and nitric oxide donors conducted with promastigotes revealed greater resistance to in vitro oxidative stress induction for Thor10, followed by Thor03. MAIN CONCLUSIONS The data obtained for the virulence factors explored here suggest how multiple coexisting phenotypic-distinct subpopulations may contribute in adaptability of a single L. (V.) braziliensis strain during infection in the host cells.

Evolución de la virulencia de SARS-CoV-2 en Chile / Evolution of the virulence of SARS CoV-2 in Chile

INTRODUCCIÓN: La evolución de la virulencia ha despertado el interés de la biología evolutiva por décadas. Se trata de co-evolución entre agentes patógenos y sus hospederos. Se han planteado diferentes hipótesis para la evolución de la virulencia, entre ellas la evolución con un compromiso virulencia-transmisión. OBJETIVO: Estudiar la evolución de la letalidad y la transmisión del SARS CoV-2 en Chile, con la hipótesis que ha existido un compromiso con disminución de la letalidad y aumento de la transmisión de esta durante la epidemia. RESULTADOS: La letalidad diaria en Chile disminuyó claramente. Aunque no se encontró correlación entre la letalidad diaria y el número reproductivo efectivo, el número reproductivo efectivo máximo asociado a cada variante viral, presentó un aumento claro desde la aparición de la variante γ en adelante (δ y O) en Chile. CONCLUSIÓN: Este estudio muestra una evolución de la virulencia con un compromiso virulenciatransmisión. Esto puede ser explicado en gran parte por la evolución viral, pero el cambio en letalidad también puede ser afectado por las intervenciones no farmacológicas y farmacológicas realizadas por la población humana.

BACKGROUND: The evolution of virulence has aroused the interest of evolutionary biology for decades. It is about co-evolution between pathogens and their hosts. Different hypotheses have been put forward for the evolution of virulence, including evolution with a virulence-transmission trade-off. AIM: To study the evolution of the fatality rate and transmission of SARS CoV-2 in Chile, with the hypothesis that there has been a trade-off to a decrease in lethality and an increase in its transmission during the epidemic. RESULTS: The daily fatality rate in Chile clearly decreased. Although no correlation was found between daily fatality rate and effective reproductive number, the maximum effective reproductive number associated with each viral variant showed a clear increase from the appearance of the γ variant onwards (δ and O) in Chile. CONCLUSION: This study shows an evolution of virulence with a virulence-transmission trade-off. This can be largely explained by viral evolution, but the change in lethality can also be affected by non-pharmacological and pharmacological interventions carried out by the human population.

Bacteremia by non-O1/non-O139 Vibrio cholerae: Case description and literature review / Bacteriemia por Vibrio cholerae no-O1/no-O139: descripción de un caso y revisión de la literatura

Bacteremia by non-O1/non-O139 Vibrio cholerae is a rare entity associated with high mortality rates. We report a case of non-O1/non-O139 V. cholerae bacteremia confirmed by polymerase chain reaction and agglutination tests. The clinicoepidemiological characteristics and therapeutic options for this infection are also described.

La bacteriemia por Vibrio cholerae no-O1/no-O139 es una entidad poco frecuente que se asocia con altas tasas de mortalidad. Se reporta un caso de bacteriemia por V. cholerae no-O1/no-O139 confirmado por reacción en cadena de la polimerasa y test de aglutinación. Se describen las características clinicoepidemiológicas y las opciones terapéuticas para esta infección.