Green-Synthesized Silver Nanoparticles in the Prevention of Multidrug-Resistant Proteus mirabilis Infection and Incrustation of Urinary Catheters BioAgNPs Against P. mirabilis Infection.

This study aimed to assess the activity of AgNPs biosynthesized by Fusarium oxysporum (bio-AgNPs) against multidrug-resistant uropathogenic Proteus mirabilis, and to assess the antibacterial activity of catheters coated with bio-AgNPs. Broth microdilution and time-kill kinetics assays were used to determine the antibacterial activity of bio-AgNPs. Catheters were coated with two (2C) and three (3C) bio-AgNPs layers using polydopamine as crosslinker. Catheters were challenged with urine inoculated with P. mirabilis to assess the anti-incrustation activity. MIC was found to be 62.5 µmol l-1, causing total loss of viability after 4 h and bio-AgNPs inhibited biofilm formation by 76.4%. Catheters 2C and 3C avoided incrustation for 13 and 20 days, respectively, and reduced biofilm formation by more than 98%, while the pristine catheter was encrusted on the first day. These results provide evidence for the use of bio-AgNPs as a potential alternative to combat of multidrug-resistant P. mirabilis infections.

Clonal relationship, virulence genes, and antimicrobial resistance of Morganella morganii isolated from community-acquired infections and hospitalized patients: a neglected opportunistic pathogen.

Morganella morganii is a bacterium belonging to the normal intestinal microbiota and the environment; however, in immunocompromised individuals, this bacterium can become an opportunistic pathogen, causing a series of diseases, both in hospitals and in the community, being urinary tract infections more prevalent. Therefore, the objective of this study was to evaluate the prevalence, virulence profile, and resistance to antimicrobials and the clonal relationship of isolates of urinary tract infections (UTI) caused by M. morganii, both in the hospital environment and in the community of the municipality of Londrina-PR, in southern Brazil, in order to better understand the mechanisms for the establishment of the disease caused by this bacterium. Our study showed that M. morganii presents a variety of virulence factors in the studied isolates. Hospital strains showed a higher prevalence for the virulence genes zapA, iutA, and fimH, while community strains showed a higher prevalence for the ireA and iutA genes. Hospital isolates showed greater resistance compared to community isolates, as well as a higher prevalence of multidrug-resistant (MDR) and extended-spectrum beta lactamase (ESBL)-producing isolates. Several M. morganii isolates from both sources showed high genetic similarity. The most prevalent plasmid incompatibility groups detected were FIB and I1, regardless of the isolation source. Thus, M. morganii isolates can accumulate virulence factors and antimicrobial resistance, making them a neglected opportunistic pathogen.

Resistance and Virulence Surveillance in Escherichia coli Isolated from Commercial Meat Samples: A One Health Approach.

Escherichia coli is a key indicator of food hygiene, and its monitoring in meat samples points to the potential presence of antimicrobial-resistant strains capable of causing infections in humans, encompassing resistance profiles categorized as serious threats by the Centers for Disease Control and Prevention (CDC), such as Extended-Spectrum Beta-Lactamase (ESBL)-a problem with consequences for animal, human, and environmental health. The objective of the present work was to isolate and characterize ESBL-producing E. coli strains from poultry, pork, and beef meat samples, with a characterization of their virulence and antimicrobial resistance profiles. A total of 450 meat samples (150 chicken, 150 beef, and 150 pork) were obtained from supermarkets and subsequently cultured in medium supplemented with cefotaxime. The isolated colonies were characterized biochemically, followed by antibiogram testing using the disk diffusion technique. Further classification involved biofilm formation and the presence of antimicrobial resistance genes (blaCTX-M, AmpC-type, mcr-1, and fosA3), and virulence genes (eaeA, st, bfpA, lt, stx1, stx2, aggR, iss, ompT, hlyF, iutA, iroN, fyuA, cvaC, and hylA). Statistical analysis was performed via the likelihood-ratio test. In total, 168 strains were obtained, with 73% originating from chicken, 22% from pork, and 17% from beef samples. Notably, strains exhibited greater resistance to tetracycline (51%), ciprofloxacin (46%), and fosfomycin (38%), apart from ß-lactams. The detection of antimicrobial resistance in food-isolated strains is noteworthy, underscoring the significance of antimicrobial resistance as a global concern. More than 90% of the strains were biofilm producers, and strains carrying many ExPEC genes were more likely to be biofilm formers (OR 2.42), which increases the problem since the microorganisms have a greater chance of environment persistence and genetic exchange. Regarding molecular characterization, bovine samples showed a higher prevalence of blaCTX-M-1 (OR 6.52), while chicken strains were more likely to carry the fosA3 gene (OR 2.43, CI 1.17-5.05) and presented between 6 to 8 ExPEC genes (OR 2.5, CI 1.33-5.01) compared to other meat samples. Concerning diarrheagenic E. coli genes, two strains harbored eae. It is important to highlight these strains, as they exhibited both biofilm-forming capacities and multidrug resistance (MDR), potentially enabling colonization in diverse environments and causing infections. In conclusion, this study underscores the presence of ß-lactamase-producing E. coli strains, mainly in poultry samples, compared to beef and pork samples. Furthermore, all meat sample strains exhibited many virulence-associated extraintestinal genes, with some strains harboring diarrheagenic E. coli (DEC) genes.

Epidemiology and characterization of Providencia stuartii isolated from hospitalized patients in southern Brazil: a possible emerging pathogen.

This study aimed to characterize the virulence factors and antimicrobial resistance of Providencia stuartii , an opportunistic pathogen that causes human infections. We examined 45 isolates of P. stuartii both genotypically and phenotypically by studying their adherence to HeLa cells, biofilm formation, cytotoxicity and antimicrobial resistance, and analysed their genomes for putative virulence and resistance genes. This study found that most isolates possessed multiple virulence genes, including fimA, mrkA, fptA, iutA, ireA and hlyA, and were cytotoxic to Vero cells. All the isolates were resistant to amoxicillin plus clavulanic acid, levofloxacin and sulfamethoxazole plus trimethoprim, and most were resistant to ceftriaxone and cefepime. All isolates harboured extended-spectrum beta-lactamase coding genes such as bla CTX-M-2 and 23/45(51.11 %) of them also harboured bla CTX-M-9. The gene KPC-2 (carbapenemase) was detected in 8/45(17.77 %) isolates. This study also found clonality among the isolates, indicating the possible spread of the pathogen among patients at the hospital. These results have significant clinical and epidemiological implications and emphasize the importance of a continued understanding of the virulence and antimicrobial resistance of this pathogen for the prevention and treatment of future infections.

Water quality monitoring in southern Brazil and the assessment of risk factors related to contamination by coliforms and Escherichia coli.

The potability of water, including underground sources, is constantly affected by human activities. To assess water quality and water security in rural and urban areas of southern Brazil, a quantitative, retrospective analysis of water samples collected monthly by the Brazilian health authorities (19,687 samples from 2013 to 2021) was performed. In rural areas, 5,979 water samples (77.54%) were found to be contaminated by coliform bacteria and 3,431 (44.50%) by Escherichia coli. In addition, 1,616 (20.95%) of the contaminated samples were significantly correlated with rainfall amount. In urban areas, 1,268 (10.95%) of the samples contained coliform bacteria and 293 (2.53%) of these samples contained E. coli, with the factor of rainfall associated with 1,081 samples (9.33%) with bacterial contamination. In terms of physicochemical parameters, turbidity exceeded the national standard (5 uT) in 448 (2.32%) samples and fluoride fell below the required level (0.8 mg/L) in 106 samples (0.54%). The presence of free residual chlorine (0.2-2.0 mg/L) was verified in 846 samples (14.38%) in rural areas and in 10,825 samples (56.13%) in urban areas. These results suggest a strong association between rainfall factors and physicochemical alterations, as well as the risk of greater microbial contamination of water for human consumption.

Topical formulations containing Trichilia catigua extract as therapeutic options for a genital and an acyclovir-resistant strain of herpes recurrent infection.

Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) infect, respectively, 67% and 13% of the world population, most commonly causing mild symptoms, such as blisters/ulcers. However, severe conditions such as keratitis, encephalitis, and systemic infections may occur, generally associated with the patient's immunological condition. Although Acyclovir® (ACV) and its analogs are the reference drugs for herpetic infections, the number of ACV-resistant HSV infections is growing exponentially. Therefore, new natural products' bioactive compounds have been studied to develop novel effective anti-herpetics. Trichilia catigua is a plant widely used in traditional medicine, including the treatment of skin diseases and sexual infections. In our study, 16 extracts from the bark of T. catigua, obtained with different solvents and their combinations, were evaluated against HSV-1 AR and HSV-2, respectively, ACV resistance and genital strains in vitro. The extracts with the highest selectivity index were used to prepare new topical anti-herpetic formulations and confirmed in vivo. Two new topical formulations were suggested to treat cutaneous and genital herpetic recurrent lesions. The cytotoxicity and antiviral activity were tested using the MTT method. The cytotoxic (CC50) and inhibitory (IC50) concentrations of 50% and the selectivity index (SI: CC50/IC50) were determined. Tc12, Tc13, and Tc16 were added to the formulations. Infected BALB/c mice were treated for 8 days, and the severity of the herpetic lesions was analyzed daily. All CEs showed a CC50 value ranging from 143 to 400 µg/mL, except for Tc3 and Tc10. Tc12, Tc13, and Tc16 showed the best SI in the 0 h, virucidal, and adsorption inhibition assays. In the in vivo test against HSV-1 AR, the infected animals treated with creams were statistically different from the infected non-treated animals and similar to ACV-treated mice. In HSV-2-infected genitalia, similar effects were found for Tc13 and Tc16 gels. The present study demonstrated that extracts from the bark of T. catigua, traditionally used in folk medicine, are a valuable source of active compounds with anti-herpetic activity. The extracts showed a virucidal mechanism of action and prevented the initial stages of viral replication. The cutaneous and genital infections were strongly inhibited by the Tc12, Tc13, and Tc16 extracts. New topical therapeutic alternatives using Trichilia catigua extracts are suggested for patients infected with ACV-resistant strains of HSV.

Prevalence of Antimicrobial Resistance and Clonal Relationship in ESBL/AmpC-Producing Proteus mirabilis Isolated from Meat Products and Community-Acquired Urinary Tract Infection (UTI-CA) in Southern Brazil.

The present study aimed to evaluate the prevalence of antimicrobial resistance and clonal relationships in Proteus mirabilis isolated from chicken meat, beef, pork, and community-acquired urinary tract infections (UTI-CA). Chicken meat isolates showed the highest multidrug resistance (MDR), followed by those from pork and UTI-CA, whereas beef had relatively few MDR strains. All sources had strains that carried blaCTX-M-65, whereas blaCTX-M-2 and blaCMY-2 were only detected in chicken meat and UTI-CA isolates. This indicates that chicken meat should be considered an important risk factor for the spread of P. mirabilis carrying ESBL and AmpC. Furthermore, ESBL/AmpC producing strains were resistant to a greater number of antimicrobials and possessed more resistance genes than non-producing strains. In addition, the antimicrobial resistance genes qnrD, aac(6')-Ib-cr, sul1, sul2, fosA3, cmlA, and floR were also found. Molecular typing showed a genetic similarity between chicken meat and UTI-CA isolates, including some strains with 100% similarity, indicating that chicken can be a source of P. mirabilis causing UTI-CA. It was concluded that meat, especially chicken meat, can be an important source of dissemination of multidrug-resistant P. mirabilis in the community.

Caracterização de Escherichia coli diarreiogênica isolada de água subterrânea para consumo humano em um assentamento rural / Characterization of diarrheagenic Escherichia coli isolated from underground water for human consumption in a rural settlement

Escherichia coli diarreiogênica (DEC) é um importante agente de infecções gastrointestinais transmitidas pela água. O trabalho teve como objetivo avaliar a qualidade microbiológica e físicoquímica de 58 amostras de água subterrânea in natura para consumo de um assentamento rural e caracterizar os isolados de E. coli, genotipicamente dentro dos patotipos de DEC, pela técnica da PCR, e fenotipicamente. Todas as amostras apresentaram contaminação por coliformes totais e 36 (62,1%) por E. coli. Em células HEp-2, dos 170 isolados de E. coli, 106 (62,36%) apresentaram AA, 15 (8,82%) AD, 17 (10%) adesão não caracterizado e 32 (18,82%) foram não aderentes. Quanto à formação de biofilme, 126 (74,12%) cepas são formadoras, e 44 (25,88%) não formaram biofilme. Foram identificadas DEC em 6,89% das amostras de água: três (5,17%) ETEC e uma (1,72%) EAEC. EAEC apresentou AA e as três cepas de ETEC apresentaram AD, AA e não definida. Todas as DEC foram formadoras de biofilme. Dois isolados de ETEC apresentaram resistência à ampicilina e tetraciclina, uma ETEC à aminoglicosídeos, e EAEC foi sensível a todos os antibióticos testados. As ETEC foram classificadas no filogrupo B1 e a EAEC no E. Os sorotipos encontrados foram: O24:H21, OR:H21, O17:H46 e O6:H12. Todas as amostras estavam dentro dos parâmetros normais de flúor e 13 (22,4%) apresentaram resultados acima do padrão permitido de turbidez. A presença de E. coli e DEC nas amostras de água indica a necessidade de adoção de medidas que evitem a contaminação da água fornecida à população, evitando, assim, a transmissão de doenças.(AU)

Diarrheogenic Escherichia coli (DEC) is an important agent of waterborne gastrointestinal infections. The objective of this work was to evaluate the microbiological and physico-chemical quality of 58 freshwater groundwater samples for the consumption of a rural settlement and to characterize the E. coli isolates, genotyped within the DEC pathophyses, by the PCR technique, and phenotypically. All water samples presented contamination with total coliforms, and 36 (62.1%) with E. coli. In HEp-2 cells, of 170 E. coli isolates, 106 (62.36%) showed AA, 15 (8.82%) AD, 17 (10%) noncharacterized adhesion and 32 (18.82%) were non-adherent. As for biofilm formation, 126 (74.12%) strains are forming, and 44 (25.88%) did not form biofilm. DEC was identified in 6.89% of the water samples with E. coli: three (5.17%) with enterotoxigenic E. coli (ETEC), and one (1.72%) with enteroaggregative E. coli (EAEC). EAEC showed aggregative adherence, whereas various ETEC strains presented diffuse, aggregative, and non-defined adherence. All DEC strains were biofilm forming. Two isolates of ETEC showed resistance to ampicillin and tetracycline, and one isolate showed resistance to aminoglycosides. The EAEC isolate was sensitive to all antibiotics tested. All ETECs were classified into phylogenetic B1 and EAEC in E. The serotypes identified in our study were: O24:H21, ONT:H21, O17:H46, and O6:H12. All water samples were within normal fluorine parameters; however, measured turbidity was above the permitted standard in 13 (22.4%) samples. The presence of E. coli and DEC in water samples indicates the need to take action to prevent contamination of water resources accessed by people to prevent the transmission of diseases.(AU)

Proteus mirabilis causing cellulitis in broiler chickens.

Given the need to understand the virulence profile of Proteus mirabilis isolates from cellulitis in broiler chickens and their ability to cause lesions, the present study aimed to characterize genotypically and phenotypically the virulence profiles of two strains of P. mirabilis isolated from cellulitis in broilers, as well as to evaluate their ability to experimentally reproduce the lesions in vivo. The strain with the highest virulence potential (LBUEL-A33) possessed mrpA, pmfA, ucaA, atfA (fimbriae), zapA, ptA (proteases), hpmA (hemolysin), and ireA (siderophore) genes, formed a very strong biofilm, and expressed the pattern of aggregative adhesion and cytotoxicity in Vero cells. The strain with the lowest virulence potential (LBUEL-A34) did not present the pmfA and ucaA genes, but expressed the pattern of aggregative adhesion, formed a strong biofilm, and did not show cytotoxicity. Both strains developed cellulitis in an animal model within 24 h post-inoculation (PI), and the degree of lesions was not significantly altered up to 120 h PI. The LBUEL-A33 strain was also inoculated in combination with an avian pathogenic Escherichia coli (APEC 046), and the lesions showed no significant changes from the individual inoculation of these two strains. Histological analysis showed that the LBUEL-A33 strain developed characteristic cellulitis lesions. Thus, both strains of P. mirabilis isolated in our study have several virulence factors and the ability to develop cellulitis in broilers.

Antibacterial Activity of Sophorolipids from Candida bombicola Against Human Pathogens

Abstract Sophorolipids are glycolipids that have natural antimicrobial properties and present great potential in the pharmaceutical field. The present study aimed to produce sophorolipids from Candida bombicola using a chicken fat-based medium and evaluate the antimicrobial activity against Gram-negative (Proteus mirabilis, Escherichia coli, Salmonella enterica subsp. enterica) and Gram-positive bacteria (Enterococcus faecium, Staphylococcus aureus and Streptococcus mutans). The production of sophorolipids reached 27.86 g L-1. Based on the structural characterization, 73.55% of the sophorolipids present a mixture of acidic monoacetylated C18:2 and lactonic diacetylated C16:0, and 26.45% were present in the diacetylated C18:1 lactonic form. Bacteria submitted to sophorolipid exposure showed a reduction in viability at doses of 500 μg mL-1 and 2,000 μg mL-1 against Gram-positive and Gram-negative bacteria, respectively. These results suggest that sophorolipids produced in chicken fat medium may be used as antimicrobial agents to prevent or eliminate contamination by different pathogens.

Molecular and phenotypic characterization of diarrheagenic Escherichia coli isolated from groundwater in rural areas in southern Brazil.

Water-borne diseases like diarrheagenic Escherichia coli (DEC)-induced gastroenteritis are major public health problems in developing countries. In this study, the microbiological quality of water from mines and shallow wells was analyzed for human consumption. Genotypic and phenotypic characterization of DEC strains was performed. A total of 210 water samples was analyzed, of which 153 (72.9%) contained total coliforms and 96 (45.7%) E. coli. Of the E. coli isolates, 27 (28.1%) contained DEC genes. The DEC isolates included 48.1% Shiga toxin-producing E. coli (STEC), 29.6% enteroaggregative E. coli (EAEC), 14.9% enteropathogenic E. coli (EPEC), 3.7% enterotoxigenic E. coli (ETEC), and 3.7% enteroinvasive E. coli (EIEC). All the STECs had cytotoxic effects on Vero cells and 14.8% of the DEC isolates were resistant to at least one of the antibiotics tested. All DEC formed biofilms and 92.6% adhered to HEp-2 cells with a prevalence of aggregative adhesion (74%). We identified 25 different serotypes. One EPEC isolate was serotype O44037:H7, reported for the first time in Brazil. Phylogenetically, 63% of the strains belonged to group B1. The analyzed waters were potential reservoirs for DEC and could act as a source for infection of humans. Preventive measures are needed to avoid such contamination.

Genotypic and phenotypic profiles of virulence factors and antimicrobial resistance of Proteus mirabilis isolated from chicken carcasses: potential zoonotic risk.

Proteus mirabilis is an opportunistic pathogen often associated with a variety of human infections acquired both in the community and in hospitals. In this context, the present work aimed to evaluate the genotypic and phenotypic characteristics of the virulence factors and antimicrobial resistance determinants of 32 P. mirabilis strains isolated from chicken carcasses in a poultry slaughterhouse in the north of the state of Paraná, Brazil, in order to assess a potential zoonotic risk. The isolates presented a variety of virulence genes that contribute to the development of infection in humans. The mrpA, pmfA, atfA (fimbriae), ireA (siderophores receptor), zapA, ptA (Proteases), and hpmA (hemolysin) genes were found in 32 (100%) isolates and ucaA (fimbriae) in 16 (50%). All isolates showed aggregative adherence in HEp-2 cells and formed biofilms. Of all strains, 27 (84.38%) showed cytotoxic effects in Vero cells. Antimicrobial susceptibility was tested using 20 antimicrobials, in which 25 (78.13%) strains were considered multidrug-resistant. The presence of blaESBL and blaampC genes conferring resistance to ß-lactams and qnr to quinolones were also detected in the isolates after presumption in the phenotypic test, in which 7 (21.88%) isolates contained the CTX-M-2 group, 11 (34.38%) contained CIT group and 19 (59.38%) contained qnrD. Therefore, chicken carcasses contaminated with P. mirabilis may pose a health risk to the consumer, as these isolates have a variety of virulence and antimicrobial resistance characteristics that can be found in P. mirabilis strains isolated from human infections.

Draft Genome Sequence of Vancomycin-Resistant Enterococcus faecium UEL170 (Sequence Type 412), Isolated from a Patient with Urinary Tract Infection in a Tertiary Hospital in Southern Brazil.

Enterococcus faecium is a leading cause of health care-associated infections, with specific lineages circulating in hospital settings worldwide. Here, we report the draft genome sequence of the multidrug-resistant and biofilm-producing E. faecium UEL170, sequence type 412 (ST412), isolated from an inpatient with a urinary tract infection. This strain is a member of clonal complex 17 (CC17), a globally hospital-associated clone.

Avaliação da presença e quantificação de coliformes totais e Escherichia coli em amostras de água destinada ao consumo humano proveniente de poços artesianos / Evaluation of the presence and quantification of total coliforms and Escherichia coli in samples of water intended for human consumption from artesian wells

A água é indispensável à vida e a sua contaminação com microrganismos patogênicos oferece grande risco à saúde humana, podendo causar doenças que variam de gastroenterites brandas a doenças fatais. Dessa forma, a água para o consumo humano deve estar livre de microrganismos patogênicos e não deve conter bactérias indicadoras de contaminação fecal, sendo a Escherichia coli o principal representante desse grupo de bactérias. Tendo em vista a importância da potabilidade da água para a saúde, o presente trabalho teve por objetivo verificar a qualidade bacteriológica da água utilizada para o consumo humano proveniente de 200 poços artesianos localizados na cidade de Cambé/Paraná, no período de 2013 a 2017, utilizando-se para tanto a análise da presença de coliformes totais e de E. coli como indicador de contaminação fecal. A metodologia empregada para a pesquisa de coliformes totais e E. coli foi o método do substrato cromogênico Colilert®. Dentre as 200 amostras analisadas, 113 (56,5%) estavam contaminadas com coliformes totais e 35 (17,5%) com E. coli. As análises realizadas durante o período de cinco anos possibilitaram encontrar 14 (7%) amostras de água tratadas que apresentavam contaminação por bactérias do grupo coliforme. A partir dos resultados obtidos nesse trabalho, espera-se conscientizar tanto a população quanto os órgãos públicos sobre a importância do controle da qualidade da água para a prevenção de doenças transmitidas por esse meio (AU)

Water is essential for life and its contamination by pathogenic microorganisms offers great risk to human health and may cause illnesses ranging from mild gastroenteritis to life threatening diseases. Thus, water for human consumption should be free of pathogenic microorganisms and must not contain indicators of faecal contamination such as Escherichia coli presence. Given the importance of drinking water quality for health, this study aimed to verify the bacteriological quality of water used for human consumption from 200 artesian wells located in the city of Cambé - Paraná, from 2013 to 2017. The methodology used for the research of total coliforms and E. coli was the Colilert® chromogenic substrate method. Among the 200 analysed water samples, 113 (56.5%) were contaminated with total coliforms and 35 (17,5%) with E. coli. The analyses carried out during the five-year period allowed finding 14 (7%) treated water samples that showed contamination by bacteria of the coliform group. Based on the results obtained in this study, it is expected that both the population and the public agencies will be aware of the importance of water quality control for the prevention of diseases transmitted by this means (AU)

Detection of Diarrheagenic Escherichia coli in Bovine Meat in the Northern Region of Paraná State, Brazil

Abstract Ground bovine meat is commonly consumed by the population of Brazil. However, it constitutes an excellent medium for the multiplication of microorganisms due to available nutrients and handling practices prior to consumption. Here, we examined 100 samples of ground beef for the presence of diarrheagenic Escherichia coli (DEC) pathotypes by PCR, and characterized isolates by analyzing their adherence to HEp-2 cells, serotype, antimicrobial susceptibility, and phylogeny. Enteroaggregative E. coli was detected in five (5%) meat samples, Shiga toxin-producing E. coli in three (3%), and atypical enteropathogenic E. coli in two (2%). According to the phylogeny, six isolates (60%) were classified in group A, two (20%) in group B1, and two (20%) in group E. The detected serotypes were O3:H2, O93:H9, O93:H46, O105ab:H7, O152:H8, O156:H10, and O175:H7. The antimicrobial susceptibility testing showed that one sample (10%) was resistant to ampicillin, two (20%) to sulfamethoxazole-trimethoprim, and two (20%) to cephalothin. Based on these results, bovine ground meat for human consumption can serve as a reservoir of DEC, which emphasizes the importance of appropriate hygienic-sanitary conditions during handling at every stage from slaughter to table.

Complete Genome Sequence of Bacillus velezensis LABIM40, an Effective Antagonist of Fungal Plant Pathogens.

Bacillus velezensis strain LABIM40 holds high potential for biological control of plant pathogens. Its complete genome contains one chromosome of 3,972,310 bp with 3,777 DNA coding sequences and displays 33 gene clusters potentially involved in the suppression of fungal pathogens.

Immunotherapy in Acute Leukemias: Implications and Perspectives Using Wt1 Antigen.

The WT1 gene encodes a transcription factor involved in regulation of many cellular processes, including proliferation, differentiation, mRNA processing and apoptosis, besides acting as a transcription repressor of growth factors and their receptors' genes. This gene is expressed at high levels in several types of cancers, including acute leukemias. In this regard, many studies have identified WT1 protein as a tumor antigen, considered a target molecule for clinical application in human acute leukemias. Immunotherapy using WT1 antigen has been effective in stimulating immune responses against leukemic cells. Regarding adoptive immunotherapy, the use of dendritic cells (DCs) for the WT1-specific cytotoxic T cells generation proved to be efficient in the development and maintenance of immunologic cells. Therefore, these therapeutic methods, that provided enthusiasm for moving ahead, highlight several opportunities and challenges to be used in clinical practice for managing acute leukemias.

Molecular detection of HpmA and HlyA hemolysin of uropathogenic Proteus mirabilis.

Urinary tract infection (UTI) is one of the bacterial infections frequently documented in humans. Proteus mirabilis is associated with UTI mainly in individuals with urinary tract abnormality or related with vesicular catheterism and it can be difficult to treat because of the formation of stones in the bladder and kidneys. These stones are formed due to the presence of urease synthesized by the bacteria. Another important factor is that P. mirabilis produces hemolysin HpmA, used by the bacteria to damage the kidney tissues. Proteus spp. samples can also express HlyA hemolysin, similar to that found in Escherichia coli. A total of 211 uropathogenic P. mirabilis isolates were analyzed to detect the presence of the hpmA and hpmB genes by the techniques of polymerase chain reaction (PCR) and dot blot and hlyA by PCR. The hpmA and hpmB genes were expressed by the RT-PCR technique and two P. mirabilis isolates were sequenced for the hpmA and hpmB genes. The presence of the hpmA and hpmB genes was confirmed by PCR in 205 (97.15 %) of the 211 isolates. The dot blot confirmed the presence of the hpmA and hpmB genes in the isolates that did not amplify in the PCR. None of the isolates studied presented the hlyA gene. The hpmA and hpmB genes that were sequenced presented 98 % identity with the same genes of the HI4320 P. mirabilis sample. This study showed that the PCR technique has good sensitivity for detecting the hpmA and hpmB genes of P. mirabilis.

Análise estrutural e funcional da região LEE de Escherichia coli enteropatogênica atípica / Structural and functional analysis of LEE region of atypical enteropathogenic Escherichia coli

Escherichia coli enteropatogênica é capaz de causar uma lesão histopatológica no epitélio intestinal conhecida como attaching-effacing (A/E) induzida por proteínas codificadas pelo locus of enterocyte effacement (LEE). EPEC é atualmente classificada em típica e atípica (aEPEC), baseado na presença ou ausência do EPEC adherence plasmid, respectivamente...

Enterophatogenic Escherichia coli is capable of cause a histopathological lession on the intestinal epithelium called attaching-effacing (A/E), triggered by proteins encoded by the locus of enterocyte effacement (LEE).EPEC is currently classified as typical and atypical (aEPEC), based on the presence or absence of the EPEC adherence plasmid, respectively...