Fusarium wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici is one of the most serious diseases responsible for substantial losses in yield and quality. In this context, this research work aims to evaluate the biocontrol and growth-promoting attributes of Bacillus subtilis BS-QS1 in greenhouse and under laboratory conditions from Shaqra, Saudi Arabia. In the present study, a randomized complete block design with four treatments, i.e., Control, Fusarium, B. subtilis, and B. subtilis+Fusarium, each replicated eight times, revealed that B. subtilis exhibited strong antifungal activity in vitro reflected by inhibition zones of 15-19mm and 60-72% reduction in mycelial growth and spore germination. Moreover, B. subtilis enhanced the activities of chitinase and β-1,3-glucanase 6-7-fold and production of siderophores over 10-fold. Under greenhouse trials, Fusarium infection reduced the plant height, shoot dry weight, and total yield by 25-46%, while exogenously applied B. subtilis enhanced the above parameters by 63, 58, and 71%, respectively. Chlorophyll a and b improved by 60 and 53%, relative water content increased by 34%, while electrolyte leakage was reduced by 30%, demonstrating the enhanced stress tolerance. Antioxidant enzyme activities improved in the range of 40-96%, while the expression of defense genes improved by 185-295% in B. subtilis-pretreated plants. In addition, DNA of Fusarium in roots was suppressed by nearly 80%, while disease incidence was reduced by 58%, confirming the strong biocontrol potential of B. subtilis. Field validation of the organism is recommended.

Among the microorganisms involved in bovine respiratory disease (BRD), certain Mycoplasma species have been associated with the severity and chronicity of infections. This study aimed to determine the frequency of Mycoplasma species in calves with respiratory disease from selected dairy herds in the states of Hidalgo and Mexico, located in Central Mexico. Nasal swabs were collected from 150 clinically affected calves from dairy herds: 35 from Melchor Ocampo, State of Mexico (Herd A); 30 from Actopan, State of Hidalgo (Herd B); and 85 from 3 herds in Tizayuca, State of Hidalgo (Herds C, D, and E). Samples were analyzed by culture and PCR targeting the uvrC gene of Mycoplasma bovis and the rpoB gene of Mycoplasma dispar and Mycoplasma bovirhinis. Specifically, M. bovis was more frequently detected in Herds A and B, with PCR positivity rates of 57.7% and 33.3% and corresponding culture positivity rates of 51.4% and 23.3%, respectively. In contrast, M. dispar predominated in Herds C, D and E, with PCR positivity rates ranging from 30% to 48% and corresponding culture positivity rates ranging from 26.6% to 36.6%. M. bovirhinis was detected at low frequencies across all herds. Sequencing analysis confirmed the identity of the detected species. The detection of M. bovis in some clinically affected calves in this study is consistent with previous evidence recognizing it as an important respiratory pathogen in cattle, whereas the detection of M. dispar and M. bovirhinis may reflect opportunistic behavior or their presence as part of the respiratory microbiota, although their role in bovine respiratory disease remains unclear.

In recent decades, there has been a significant increase in the emergence of infectious diseases, many of which are transmitted by ectoparasites such as fleas and ticks. In the Southern Hemisphere, transmission by these vectors is primarily associated with bacteria of the genus Rickettsia. Although the presence of Rickettsia spp. in Argentina has been previously reported, this study investigates the presence and identity of these pathogens in fleas and ticks collected from pets (Felis catus and Canis lupus familiaris) in the central region of Argentina. A total of 144 ectoparasite pools were analyzed, including 59 flea pools and 85 tick pools. Only Ctenocephalides felis felis and Rhipicephalus sanguineus sensu lato were identified. All tick pools tested negative for Rickettsia spp. However, 35.6% of C. f. felis pools (21/59) tested positive for Rickettsia sp. and sequence analysis of the ompA and ompB genes identified Rickettsia felis. Of these 21 positive pools, 10 were from dogs and 11 from cats. The minimum infection rate was 13.2%. Sequence analysis of PCR products showed 100% identity with R. felis sequences published in GenBank. Phylogenetic analysis of the ompB gene confirmed 100% identity with known R. felis sequences. Our findings confirm the presence of R. felis in fleas from pets in central Argentina. Despite the absence of reported human cases, enhanced surveillance is essential to assess the public health risk and understand the transmission dynamics of this pathogen in urban and peri-urban environments. These findings contribute to expanding the known geographic distribution of bacteria of the genus Rickettsia and support the role of C. f. felis as a potential vector and reservoir of this pathogen.

Methicillin-susceptible Staphylococcus aureus (MSSA) clonal complex CC398 carrying ermT has emerged as a prevalent lineage in human bloodstream infections in South America. We analyzed 77 S. aureus isolates from processed foods in Misiones and northern Corrientes, Argentina, from a retrospective (2009-2010, n=36) and a prospective cohort (2020-2024, n=41). Antimicrobial susceptibility was determined by disk diffusion and the D-test. Based on a two-step phenotypic selection (methicillin susceptibility and the D-test), 20 MSSA-iMLSb positive isolates were identified, of which 14 were analyzed by PCR for the presence of the sau1-hsdS1 and ermT genes. All 14 isolates tested positive for both markers, consistent with their assignment to CC398. A marked increase in the iMLSb phenotype was observed between cohorts: 2.8% (1/36) in 2009-2010 versus 46% (19/41) in 2020-2024. This is the first report of CC398-MSSA-ermT+ in processed foods from northeastern Argentina, with evidence of its circulation dating back to at least 2009-2010.

This study aimed to investigate the occurrence of Escherichia coli isolates in retail poultry from open-air markets and supermarkets in the metropolitan region of Belém, State of Pará, Brazil, and to characterize their antimicrobial resistance profiles and the presence of selected virulence-associated genes. In this study, 14 chicken samples were collected from open-air markets (n=7) and supermarkets (n=7) and subjected to microbiological analysis and multiplex PCR to detect the iss and tsh virulence genes. Following strain identification, antimicrobial susceptibility testing (AST) was performed to evaluate the effects of five antimicrobial agents (amoxicillin, cephalexin, doxycycline, enrofloxacin, and sulfamethoxazole). Microbiological analysis showed that E. coli was detected in 71.42% (10/14) of the chicken carcasses. In contrast, PCR detected at least one virulence gene in all positive samples, with the iss gene being identified in 100% and the tsh gene in 85.7% (12/14) Among the 25 E. coli isolates obtained from the organs of chickens from both retail sources, 76% were resistant to enrofloxacin (76%), sulfamethoxazole (40%), doxycycline (36%), amoxicillin (32%), and cephalexin (28%). These findings indicate that retail broilers may harbor E. coli strains carrying virulence genes and exhibiting multidrug resistance, suggesting a potential public health concern for food safety.

The HIV/AIDS epidemic remains a major global public health challenge, and the emergence of drug resistance mutations compromises treatment efficacy. The aim of this study was to characterize HIV-1 genetic diversity and antiretroviral drug resistance mutations circulating in Peruvian infants under 18 months of age. A descriptive cross-sectional study was conducted using 28 samples collected between 2017 and 2018. Genetic material was obtained from whole blood (proviral DNA) and plasma (viral RNA), and then analyzed using nested PCR amplification and next-generation sequencing (NGS). HIV-1 subtypes were determined through a phylogenetic analysis, and resistance mutations were identified using the HYDRA and Stanford HIVdb platforms. Subtype B was the most prevalent (89%), followed by circulating recombinant forms CRF17_BF and CRF89_BF (11%). Four out of 28 samples (14.3%) harbored at least one resistance-associated mutation. The most frequently detected mutations included K103N (7.1%), V106I (3.6%), V179E (7.1%), and G190A (3.6%), with 21.4% of the identified mutations associated with non-nucleoside reverse transcriptase inhibitors (NNRTIs). Notably, this study reports the first detection of CRF89_BF in Peruvian infants under 18 months of age. These findings highlight the importance of ongoing molecular surveillance of HIV-1 diversity and antiretroviral resistance mutations to optimize treatment strategies and strengthen HIV control programs.

Human herpesvirus-8 (HHV-8) causes lymphoproliferative diseases, but recent studies suggest it may also be linked to neuropsychiatric disorders. This study aimed to determine HHV-8 IgG seroprevalence in individuals with schizophrenia and blood donors, as well as to evaluate whether HHV-8 constitutes a risk factor for schizophrenia. A total of 135 patients diagnosed with schizophrenia based on DSM-V criteria and 200 healthy blood donors were included. HHV-8 IgG antibodies were analyzed using ELISA, and molecular detection of HHV-8 DNA was performed by real-time PCR. The seropositivity rates between the groups were statistically compared. HHV-8 IgG positivity was detected in 6.7% of schizophrenia patients (9/135, CI: 3.1-12.3) and 5.0% of blood donors (10/200, CI: 2.4-9.0) (p=0.518). HHV-8 DNA was not detected in any of the serum samples that tested positive for HHV-8 IgG. No statistically significant association was observed between HHV-8 seropositivity and schizophrenia (OR=1.36; 95% CI: 0.53-3.43; p=0.519). Brief Psychiatric Rating Scale (BPRS) total scores were similar between IgG-positive (median 27, IQR 17-42; mean 47.0±13.3) and IgG-negative patients (median 26, IQR 20-34; mean 45.0±10.8) (p=0.678). Although some BPRS parameters appeared higher in IgG-positive patients, none were statistically significant after multiple testing correction. In this study, HHV-8 IgG seroprevalence was similar between schizophrenia patients and blood donors, and no statistically significant association was observed between HHV-8 seropositivity and schizophrenia. To enhance the generalizability of the findings, larger studies with increased sample size, as well as comparative, regional, and multicenter designs, are needed.

MALDI-TOF mass spectrometry has revolutionized microbial identification in the clinical microbiology laboratory. However, barriers in the analysis of mass spectra with databases different from the proprietary prevent this technology from achieving its full potential. The goal of this study was to develop an informatics tool capable of converting peak lists obtained from MALDI-TOF mass spectra to an XML compatible with open data bases, such as MicrobeNet. This innovation makes it possible to overcome limitations in interoperability between commercial platforms, allowing for the optimization and decentralization of microbial identification. A set of mass spectra acquired with MALDI Biotyper and VITEK MS were analyzed, showing high concordance between the converter approach and the standard workflow (MALDI Biotyper: 96.4% (95% CI: 89.4-99.4%) VITEK MS: 87.4% (95% CI: 83.0-91.1%)). This converter promises to become a cost-effective alternative to broaden the clinical microbiology laboratory's diagnostic capacity.

Carnivore protoparvovirus 1 (CPPV-1) is a significant pathogen of domestic carnivores, but its occurrence and genomic diversity in South American wildlife remain poorly characterized. Here we report the first detection and complete-genome characterization of an FPV-like CPPV-1 strain in a Procyon cancrivorus from Northeastern Argentina. Viral DNA was sequenced using tiling-tailed amplicons and NGS (95.4% genomic coverage, mean depth >1700×). Phylogenetic analysis of global genomes indicated that the P. cancrivorus strain clustered robustly within the FPV-like clade and was closely related to FPV variants circulating in domestic cats in Argentina. The CPPV-1 positive individual was clinically healthy, suggesting subclinical spillover at the wildlife-domestic interface. These findings extend the recognized host range of FPV-like parvoviruses in South America and underscore the need for genomic surveillance to monitor cross-species transmission at the wildlife-domestic interface.

Domestic pigeons (Columba livia domestica) are potential reservoirs of opportunistic yeasts that may pose health risks to humans, particularly in urban environments. This study aimed to investigate the prevalence, seasonal distribution, and molecular identification of Candida species in pigeon feces across Riyadh, Saudi Arabia. Fecal samples were collected from 64 pigeons across four regions of Riyadh during all four seasons. Yeasts were isolated using selective Sabouraud dextrose agar and CHROMagar Candida, purified, and preserved. Species-level identification was performed via morphological analysis, MALDI-TOF mass spectrometry (MS), and molecular techniques targeting the ITS1-5.8S-ITS2 region. Phylogenetic analysis was conducted on confirmed Candida albicans isolates. Overall, 20.31% (n=13) of the samples were positive for fungal isolation. The predominant species were C. albicans, Pichia kudriavzevii, and Clavispora lusitaniae. Seasonal analysis revealed the highest prevalence in spring (7.81%), while the central region of Riyadh showed the highest regional prevalence (7.81%). MALDI-TOF MS successfully identified C. lusitaniae and P. kudriavzevii, whereas C. albicans was confirmed via PCR and ITS sequencing (GenBank: OR467467 and OR467468). Phylogenetic analysis placed C. albicans isolates in a well-supported monophyletic clade. Environmental factors such as temperature and humidity influenced fungal prevalence. Cryptococcus neoformans was not detected. Domestic pigeons in Riyadh serve as environmental reservoirs of pathogenic Candida species, highlighting potential public health risks, particularly for immunocompromised individuals. These findings emphasize the need for monitoring urban bird populations to mitigate opportunistic fungal transmission.