Bianca Mendes Maciel

Microbial bioprospecting in contaminated environments is a promising strategy for identifying biosurfactant-producing bacteria; however, translating environmentally adapted strains into predictable cultivation processes remains challenging. In this study, a microbial consortium subjected to long-term evolutionary laboratory adaptation in oily sludge was investigated to evaluate strain-specific phenotypic responses related to biosurfactant production. Phylogenetic analysis based on 16S rDNA sequencing identified three taxonomically distant isolates: Faucicola sp. strain BS5C, Pseudomonas sp. strain BS16B, and Enterobacter sp. BS14MR. Biosurfactant production was evaluated using a sequential Design of Experiments (DOE) approach, including fractional factorial and central composite rotatable designs, with the emulsification index (E24) used as a semi-quantitative response variable. Initial screening revealed a statistically significant negative effect (p < 0.10) of high dextrose concentrations for all isolates. Strain-specific differences in model adequacy were observed, with a statistically adequate quadratic model obtained for Pseudomonas sp. BS16B (R² = 0.8658, p = 0.0225), whereas the other isolates showed significant lack of fit (p < 0.05). ATR-FTIR analysis revealed spectral profiles consistent with lipopeptide-like compounds. Overall, these results indicate that isolates derived from the same long-term adapted system may differ substantially in process predictability, suggesting that productivity-based screening alone may be insufficient for selecting robust strains.

This study aimed to identify Leishmania species in small non-flying mammals captured in semi-deciduous forest fragments of the Atlantic Forest and pastures in the Southwest region of Bahia state, Northeast Brazil. A total of 445 animals belonging to 11 different species were captured, the majority being rodents (75.7%; 337), followed by marsupials (24.2%; 108), and the most prevalent species were Cerradomys vivoi, Calomys expulsus, Necromys Lasiurus, and Marmosops incanus. Liver, spleen, kidney, heart, and lung fragments were collected for subsequent molecular diagnosis. Leishmania spp. kDNA amplification in positive samples was performed using real-time polymerase chain reaction (qPCR). Species identification of Leishmania was conducted through nested PCR, followed by sequencing. Leishmania spp. infection was detected in 2.92% (13/445) of the animals. Sequencing revealed that L. infantum infected three animals, while the species of the agent in the other animals could not be determined. The results indicate the presence of Leishmania spp. in the studied region, primarily affecting the local wildlife. These findings not only highlight the risk of transmission to domestic animals and humans in close contact with forest remnants, but also underscore the critical role of these fragments in supporting native fauna. However, it is worth noting that the continuous deforestation of these forest remnants could lead to increased contact between wildlife, domestic animals, and humans, thereby elevating the risk of transmission.

The objective of this research was to investigate knowledge and practices that 2nd year high school students have on Microbiology and Food Safety and apply practical interventions in Biology classes with focus on experimental classes. Fifty-nine students were evaluated through questionnaires after the workshops. The results were analyzed from a qualitative and quantitative proposal and were treated in the form of simple frequencies and percentages. During four months, four different practical approaches were carried out in Biology classes, highlighting the formulation of hypotheses and the application of workshops. The experimental classes in the Biology discipline made the students participate, elaborate hypotheses, make connections between the new knowledge and the existing ones and position themselves in this dynamics of the knowledge achieved.

The rapid diagnosis of bovine tuberculosis (BT) allows official surveillance institutions to act in areas that could be potential hotspots for the spread of the disease. The study aimed to identify the Mycobacterium bovis agent by multiplex PCR of isolated colonies. Through the official inspection service (Federal/State), samples suggestive of BT were collected during the post-mortem inspection of bovine carcasses in slaughterhouses and sent to the laboratory for complementary diagnostics. The samples were analyzed using bacteriological culture and Ziehl-Neelsen staining. In isolates characterized as Acid-Alcohol Resistant Bacilli (BAAR), the multiplex PCR technique confirmed the agent Mycobacterium bovis. Nine hundred ninety-one thousand three hundred sixteen cattle carcasses were inspected, collecting 32 BT-suggestive samples in from animalsfrom 30 municipalities. Of these, 28.1% (9/32) showed growth on bacteriological culture media with BAAR. The BAAR isolates submitted to multiplex PCR confirmed the presence of M. bovis. The multiplex PCR technique associated with bacteriological examination and applied to post-mortem findings enabled the diagnosis of M. bovis in the municipalities sampled in the Bahia state.

O diagnóstico rápido da tuberculose bovina (TB), permite a atuação de instituições oficiais de vigilância em áreas que possam constituir possíveis focos de propagação da doença. Essa pesquisa identificou o agente Mycobacterium bovis através do PCR multiplex das colônias isoladas. Através do serviço de inspeção oficial (Federal e Estadual), foram coletadas amostras sugestivas de TB durante a inspeção post-mortem de carcaças bovinas em matadouros-frigoríficos e estas foram encaminhadas ao laboratório para os diagnósticos complementares. As amostras foram comprovadas por meio de cultura bacteriológica e coloração Ziehl-Neelsen. Nos isolados caracterizados por Bacilos ÁcidoÁlcool Resistente (BAAR), aplicou-se a técnica de PCR multiplex visando a confirmação do agente Mycobacterium bovis. Foram analisadas 991.316 carcaças de bovinos. Entre estas, 32 apresentaram amostras sugestivas de TB que foram coletadas, provenientes de animais de 30 municípios. Entre as amostras coletadas, 28,1% (9/32) apresentaram crescimento em meios de cultura bacteriológicos com BAAR. Os BAAR isolados submetidos à PCR multiplex confirmaram a presença de M. bovis. A técnica de PCR multiplex associada ao exame bacteriológico e aplicada aos achados post-mortem permitiu o diagnóstico de M. bovis nos municípios amostrados do estado da Bahia.

One of the greatest challenges in poultry production is maintaining intestinal mucosal barrier integrity and gut microbiota balance. Safe alternative antimicrobials that can regulate the microbial community through animal feed have been the subject of research in poultry production. This study evaluated the effect of Mentha piperita and Melaleuca alternifolia essential oils (EOs) on the gut microbiome and morphometry of broiler quails under normal feeding conditions. The gut microbiome was studied using a completely randomized design consisting of 4 treatments, namely control, bacitracin zinc, and the Eos M. piperita and M. alternifolia, with 8 repetitions and 7 quails per treatment, totaling 224 quails from 1 to 42 days old. The intestinal contents of the slaughtered quails were collected to evaluate the gut microbiome profile of their digestive tract. Gut morphometry was analyzed using a completely randomized factorial design, with four experimental rations for three intestinal sections (4x3) and five replications. The variables studied were villus surface area and height, crypt depth, villus height to cryptdepth ratio (VH:CD), villus-crypt ratio (V:C), villus width to height ratio (VW:H), and height of the intestinal epithelium and musculature. M. alternifolia (50 mg/kg of feed) in the diet of broiler quails improved gut morphometry, similar to the results obtained with bacitracin zinc. This EO also altered the gut microbiome of quails and reduced pathogenic bacterial diversity.

Salmonella spp. are known to persist in the environment. Wild animals are believed to act as important reservoirs, with antimicrobial resistance frequently occurring in the environment. However, little is known about the role of the wildlife in Bahia as a reservoir for Salmonella in Brazil. This study aimed to isolate and characterize Salmonella spp. from wildlife in the Atlantic Forest and Caatinga biomes considering indicators such as the animal species, degree of anthropization, sampling area, and feeding habits. Convenience wildlife sampling and characterization were conducted, followed by microbiological and molecular identification of Salmonella isolates, serotyping, and antimicrobial susceptibility testing. A total of 674 fecal samples were collected from 12 municipalities during 2015–2021, and 4 were positive for the following Salmonella species: Salmonella enterica subspecies enterica serovar Agona (n = 1), Salmonella enterica subsp. enterica serogroup O:16 (n = 2), and Salmonella enterica subsp. enterica serovar Muenchen (n = 1). Antimicrobial susceptibility analysis revealed that one isolate was resistant to six antibiotics, including extended-spectrum penicillins and beta-lactamase inhibitors. These results indicated a low frequency of Salmonella spp. in the sampled forest fragments. The presence of Salmonella in wild animals increases the risk to public health and biodiversity and indicates that they can act as sentinels of environmental contamination or indicators of preservation.

The objective of this study was to examine the effects of replacement of an antibiotic (ANT, chlorohydroxyquinoline) in the diet of weaned piglets with a prebiotic composed of β-glucans, glucomannans, and mannan-oligosaccharides on growth performance, diarrhea occurrence (DO), hematological parameters, pH of digestive content, organ weights, intestinal epithelium morphology, and intestinal bacterial counts. A total of 120 piglets (weaned at 21 d old; 6.32±0.10 kg BW) were allocated in a randomized block design, with six pens replicates and four [...] ABSTRACT The objective of this study was to examine the effects of replacement of an antibiotic (ANT, chlorohydroxyquinoline) in the diet of weaned piglets with a prebiotic composed of β-glucans, glucomannans, and mannan-oligosaccharides on growth performance, diarrhea occurrence (DO), hematological parameters, pH of digestive content, organ weights, intestinal epithelium morphology, and intestinal bacterial counts. A total of 120 piglets (weaned at 21 d old; 6.32±0.10 kg BW) were allocated in a randomized block design, with six pens replicates and four

Practical methodologies that include food safety and hygiene education in pedagogical activities are strategies to prevent foodborne diseases (FBDs). Thus, the aim of this study was to investigate the knowledge of 7th‐grade middle school students regarding food microbiology and food safety, and to apply workshop‐based educational strategies that focus on scientific literacy. The students (144) were initially evaluated using a Likert‐scale questionnaire (pre‐intervention, Q0) with ten objective questions on microbiology and food safety. Once the questionnaire was evaluated, interventions were conducted through five science workshops of 50 min, over a period of 5 months. The workshops included educational games, laboratory practices, videos, and lectures that addressed microorganisms that are known to cause the most common FBDs in Brazil. After each workshop, students were asked to express their opinions and understanding of the content through semi‐structured interviews. Six months after the end of the practical interventions, the students completed a second identical Likert‐scale questionnaire (post‐intervention, Q1), and the answers to both questionnaires (Q0 and Q1) were analyzed by calculating the middle rank. The middle rank of Q1 (mean = 0.65 ± 0.13) was 21% greater than the middle rank of Q0 (mean = 0.44 ± 0.16), and statistical significance was observed (p = .0135). This demonstrates that new information acquired during the workshops positively influenced learning. We believe that when practical approaches to food safety are included in school education as a priority, the prevalence of FBD will decrease.