Brazilian Journal of Microbiology最新文献

Leptospirosis is a globally distributed infectious disease caused by pathogenic spirochetes of the Leptospira genus, often overlooked. It is estimated that the disease affects approximately one million people annually, resulting in more than 58,900 deaths. The gold standard for serodiagnosis of leptospirosis is the Microscopic Agglutination Test (MAT). However, the limitations of this technique necessitate the exploration of alternative diagnostic methods. In this study, we evaluated the ErpY-like recombinant protein (rErpY-like) in the development of a serologic diagnostic assay for human leptospirosis. Eighty-six human sera samples, characterized by MAT, underwent evaluation through indirect IgM-ELISA and IgG-ELISA. The sensitivity and specificity values obtained from IgM-ELISA were 60% and 76%, respectively, while those from IgG-ELISA were 96.4% and 100%, respectively. The use of the rErpY-like protein in both IgM-ELISA and IgG-ELISA proves to be a sensitive and specific method for antibody detection. This could potentially serve as a valuable alternative tool in the diagnosis of human leptospirosis.

Helicobacter pylori is a major cause of gastrointestinal disorders such as chronic gastritis, peptic ulcers, mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. It is estimated that around half of the world's population is infected with this pathogen, with underdeveloped countries reporting the highest frequencies. The genes cagA, cagM, vacA, and oipA are some of the most important virulence factors of H. pylori; however, there are no recent studies from Recife-PE demonstrating their frequency, and their relationship with severe gastric modifications. This work aims to use qualitative PCR to detect the virulence genes cagA, cagM, vacA, and oipA in H. pylori isolates obtained from patients in a public hospital in Recife (PE). We collected samples from the stomach's body and antrum of 147 patients, from which 71 (48%) tested positive for H. pylori. Among positive samples, the most frequently infected gender was female (44/71, 62%), and the most frequently infected age group was those above the age of 46 (31/71, 44%). Histological examination of H. pylori-positive samples revealed alterations other than chronic gastritis, including metaplasia and atrophy. The frequency of cagA, cagM, and oipA genes were identified in 84%, 56%, and 69% of the samples tested, respectively, as well as the vacA-s1m1 allelic combination (77%). However, there was no statistically significant variation in the occurrence of these genes, therefore they cannot be considered unique markers of severity in our setting. New research with larger samples and investigations of other genetic markers can aid uncover local risk factors and lead to a better understanding of H. pylori's pathogenesis.

Bacterial Cellulose (BC) offers a wide range of applications across various industries, including food, biomedical, and textiles, owing to its distinctive properties. Its unique 3D reticulated network of cellulose nanofibers, imparts excellent mechanical qualities, a high water-holding capacity, and thermal stability. Additionally, it possesses remarkable biocompatibility, biodegradability, high crystallinity, and purity. These attributes have offered significant interest in BC within both academic and industrial sectors. However, BC production is associated with high costs due to the use of expensive growth media and low yields. The study reports the potential of our indigenous isolate, Komagataeibacter saccharivorans BC-G1, as BC producer. Statistical optimization of BC production was carried out using Placket-Burman design and Central composite design, by selecting different parameters. Eight significant factors such as temperature, pH, glucose, yeast, peptone, acetic acid, incubation time and % inoculum were studies using ANOVA-based response surface methodology. Results showed that BC yield (8.5 g/L) with 1.8-fold after optimization of parameters. Maximum cellulose production (8.5 ± 1.8 g/L) was obtained using 2% glucose, 0.3% yeast extract, 0.3% peptone, 0.75% (v/v) acetic acid at pH 7.0 for 10 days of incubation with 4% inoculum at 25 °C under static culture. Main effect graph showed incubation time and acetic acid concentration as the most significant parameters affecting BC production in our study. The physicochemical characterization of produced BC was done using FTIR, XRD and SEM techniques.

Sporotrichosis is recognized as the predominant subcutaneous mycosis in South America, attributed to pathogenic species within the Sporothrix genus. Notably, in Brazil, Sporothrix brasiliensis emerges as the principal species, exhibiting significant sapronotic, zoonotic and enzootic epidemic potential. Consequently, the discovery of novel therapeutic agents for the treatment of sporotrichosis is imperative. The present study is dedicated to the repositioning of pharmaceuticals for sporotrichosis therapy. To achieve this goal, we designed a pipeline with the following steps: (a) compilation and preparation of Sporothrix genome data; (b) identification of orthologous proteins among the species; (c) identification of homologous proteins in publicly available drug-target databases; (d) selection of Sporothrix essential targets using validated genes from Saccharomyces cerevisiae; (e) molecular modeling studies; and (f) experimental validation of selected candidates. Based on this approach, we were able to prioritize eight drugs for in vitro experimental validation. Among the evaluated compounds, everolimus and bifonazole demonstrated minimum inhibitory concentration (MIC) values of 0.5 µg/mL and 4.0 µg/mL, respectively. Subsequently, molecular docking studies suggest that bifonazole and everolimus may target specific proteins within S. brasiliensis- namely, sterol 14-α-demethylase and serine/threonine-protein kinase TOR, respectively. These findings shed light on the potential binding affinities and binding modes of bifonazole and everolimus with their probable targets, providing a preliminary understanding of the antifungal mechanism of action of these compounds. In conclusion, our research advances the understanding of the therapeutic potential of bifonazole and everolimus, supporting their further investigation as antifungal agents for sporotrichosis in prospective hit-to-lead and preclinical investigations.

The worldwide prevalence of antimicrobial resistance coupled with the unavailability of newer antibiotics, has brought the sharp focus back among the scientific community, towards the discovery of novel alternative therapeutics to tackle the menace. Consequently, in the current post-antibiotic era, 'Bacteriophage Therapy' has emerged as one of the most promising option to address this problem. Bacteriophages, actually discovered long back, has shown greater potential to kill various bacterial pathogens, including the resistant clinical ones. Some of the other advantages for the use of bacteriophage therapy to treat infectious diseases include, wider availability of these microorganisms in nature, host-specific action, absence of any significant side-effects in humans and most often also exhibiting a broader anti-bacterial potential. In the recent times, the potential of phage therapy has been demonstrated in various treatments, clinical trials and infection models across the globe, where even antibiotics have completely failed. To address the global threat of AMR, WHO and UN have jointly illustrated "One Health" approach, recently extending the context to bacteriophage therapy. Many pharmaceutical companies have also recently started employing bacteriophages for developing different kinds of formulations for catering to medical and other industries. It has even shown great effect as combinatorial therapy along with antibiotics, to treat or manage various critical antibiotic resistant clinical infections. This continuously expanding potential of the bacteriophages holds great promise in the future, in the fight against the rising threat of AMR globally.

Campylobacter is gram-negative bacteria considered the predominant genera isolated from poultry samples and associated with gastroenteritis. Due to the problems in conventional cultural methods of time-consuming and technically demanding requirements, a rapid and feasible method for their identification and discrimination of the closely related spp. Including Campylobacter coli, Campylobacter fetus, and Campylobacter jejuni is needed. This study analyzes the chicken and sheep meats samples (n = 125) using culture and pre-enrichment-based Quadraplex real-time PCR by targeting OrfA, CstA, HipO, and 16 S rRNA genes of C. coli, C. fetus, C. jejuni and Campylobacter spp. Respectively. The analysis of 125 chicken and sheep meat samples by culture and real-time PCR showed high concordance between the results of the two methods. The present study show high prevalence of Campylobacter species (35% and 32% from chicken and meat respectively) of which C. jejuni were the most abundant. Reaction efficiencies were between 90 and 110%, and detect as low as 8.9 fg in C. jejuni. The need for quick detection and discrimination methods in sheep and chicken meat can be met using the described Quadraplex real-time PCR methodology.

We assessed, in a field experiment, the effects of arbuscular mycorrhizal fungi (Rhizophagus intraradices) and plant growth-promoting bacteria (Azospirillum brasilense) on the soil biological activity and the growth of key pioneer species used in the revegetation of coal-mining areas undergoing recovery. We applied four inoculation treatments to the pioneer plant species (Lablab purpureus, Paspalum notatum, Crotalaria juncea, Neonotonia wightii, Stylosanthes guianensis, Andropogon gayanus and Trifolium repens) used in the recovery process: NI (Control - Non-inoculated), AZO (A. brasilense), AMF (R. intraradices), and co-inoculation of AZO and AMF. On the 75th and 180th days, we measured plant dry mass, mycorrhizal colonization, N and P concentration, and accumulation in plant tissue. We collected soil to quantify glomalin content and soil enzyme activity. After 180 days, we did a phytosociological characterization of the remaining spontaneous plants.The both microorganisms, singly or co-inoculated, promoted increases in different fractions of soil glomalin, acid phosphatase activity, and fluorescein diacetate activity at 75 and 180 days. The inoculation was linked to higher plant biomass production (62-89%) and increased plant P and N accumulation by 34-75% and 70-85% at 180 days, compared with the non-inoculated treatment. Among the pioneer species sown Crotalaria juncea produced the highest biomass at the 75th and 180th days (67% and 76% of all biomass), followed by Lablab purpureus (3% and 0.5%), while the other species failed to establish. At 180 days, we observed twenty spontaneous plant species growing in the area, primarily from the Poaceae family (74%). That suggests that the pioneer species present in the area do not hinder the ecological succession process. Inoculation of R. intraradices and A. brasilense, isolated or combined, increases soil biological activity, growth, and nutrient accumulation in key pioneer plant species, indicating the potential of that technique for the recovery of lands degraded by coal mining.

Stenotrophomonas maltophilia (S. maltophilia) is an intrinsically drug-resistant and biofilm-forming bacteria causing infections in immunocompromised humans. This study reports the isolation of five S. maltophilia strains from saliva and gingival crevicular fluid (GCF) of AIDS patients with periodontitis in São Paulo, Brazil, showing resistance to ceftazidime, strong biofilm formation capacity and a close genetic relationship. The presence of S. maltophilia strains in saliva and CGF of patients with AIDS and periodontitis is a concern for the presence and persistence of intrinsically resistant bacteria in the oral environment, enhancing the risk for the development of severe infections in immunocompromised patients.

The Caatinga biome occurs only in Brazil and offers epidemiological conditions that should be assessed differently from other regions of Brazil and the world. Thus, the aim of this survey was to identify antimicrobial resistance, enterotoxin and biofilm production genes in Staphylococcus spp. isolated from facilities and fomites in a veterinary hospital in Caatinga biome. Samples were collected from surfaces of small animal clinical care tables (n =8), cages in the dog and cat hospitalisation sector and animals with infectious diseases (n = 21), small animal surgical centre (n =8), sterilisation sector (n =7) and stethoscopes (n = 32) by using sterile swabs. Bacterial isolation and identification, antimicrobial resistance phenotypic test and molecular detection of antimicrobial resistance, biofilm formation and enterotoxin genes were carried out. Ninety-five bacterial isolates were obtained, and 29 (30.5%) were identified as Staphylococcus spp. Overall, 13 isolates (44.8%) of six species of Staphylococcus spp. showed antimicrobial resistance profile, as well as S. haemolyticus expressed phenotypic profile of multidrug resistance. The antimicrobials with the highest resistance rates were penicillin and tetracycline. The most frequent resistance genes were blaZ and tetM, both detected in 10 (76.9%) isolates. The mecA, tetL and tetK genes had frequencies of 38.5% (5/13), 23.1% (3/13) and 15.4% (2/13), respectively. The biofilm production marker, icaD gene, was detected in one S. sciuri strain. SEE gene, which encodes enterotoxins, was detected in 15.4% (2/13) of the strains (S. pseudintermedius and S. intermedius). The occurrence of Staphylococcus spp. carrying resistance genes to diferent classes of antimicrobials, presenting MDR phenotypic pattern and carrying enterotoxins and biofim encoding genes recovered from veterinary hospital facilities and fomites in the Caatinga biome reinforce the need to implement prevention cares in veterinary practices to avoid One Health-concerning conditions.

Multidrug-resistant pathogenic vibrios are a crisis of concern as they cause multiple illnesses, including gastroenteritis in humans and acute hepatopancreatic necrosis in aquaculture. In the current study, we investigated the prevalence of the beta-lactamase gene CTX-M-group 1 in Vibrio spp. (Vibrio cholerae and Vibrio parahaemolyticus) from the water and sediment of urban tropical mangrove ecosystems of Kerala, southwest India. A total of 120 isolates of Vibrio spp. were tested for antibiotic susceptibility to 14 antibiotics. In water, ampicillin resistance was very high in isolates of V. cholerae (94.1%, n = 17) and V. parahaemolyticus (89.1%, n = 46). 26.9% of V. parahaemolyticus and 14.2% of V. cholerae harbored the CTX-M-group 1 gene in water samples. Compared to V. cholerae, the CTX-M-group 1 gene was exclusively hosted by V. parahaemolyticus (49%) in sediment samples. A significant difference in the prevalence of the CTX-M-group 1 gene was observed among Vibrio spp. in both water and sediment samples (p < 0.05). The results revealed the presence of multidrug-resistant and beta-lactamase harboring Vibrio spp. in mangrove ecosystems, which may have evolved as a consequence of the misuse and abuse of broad-spectrum antibiotics as prophylaxis in human health care and aquaculture.