Food safety knowledge among 7th-grade middle school students: A report of a Brazilian municipal school using workshop-based educational strategies.

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.

SARS-CoV-2 Infection in Cities from the Southern Region of Bahia State, Brazil: Analysis of Variables Associated in Both Individual and Community Level.

The COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), challenged public health systems worldwide. Individuals in low-income countries/regions are still at individual and community risk concerning inequality, sanitation, and economic conditions. Besides, during the pandemic, the transmission in municipalities and communities in the countryside and less developed regions kept viral spread and required structured and strengthened clinical and laboratory surveillance. Here, we present an observational, analytic, cross-sectional study conducted using secondary data from the Laboratório de Farmacogenômica e Epidemiologia Molecular (LAFEM)-Universidade Estadual de Santa Cruz (UESC), to evaluate individual and community factors associated to SARS-CoV-2 infection in outpatients from different cities from Southern Region of Bahia State, in Brazil. The data were collected between June 2021 and May 2022. The SARS-CoV-2 positivity by RT-qPCR was correlated with low socio-economic indicators, including the Human development index (HDIc) and Average worker salary (AWSc). Besides, in general, females were less likely to test positive for SARS-CoV-2 (OR = 0.752; CI 95% 0.663-0.853; p < 0.0001), while brown individuals had more positivity for infection (p < 0.0001). In addition, those who had clinical symptoms were more likely to test positive for SARS-CoV-2 (OR = 6.000; CI 95% 4.932-7.299; p < 0.0001). Although dry cough, headache, and fever were the most frequent, loss of taste (OR = 5.574; CI 95% 4.334-7.186) and loss of smell (OR = 6.327; CI 95% 4.899-8.144) presented higher odds ratio to be positive to SARS-CoV-2 by RT-qPCR. Nonetheless, the distribution of these characteristics was not homogenous among the different cities, especially for age and gender. The dynamic of SARS-CoV-2 positivity differed between cities and the total population and reinforces the hypothesis that control strategies for prevention needed to be developed based on both individual and community risk levels to mitigate harm to individuals and the health system.

Low Occurrence of Salmonella spp. in Wild Animals in Bahia, Brazil-Population Assessment and Characterization in the Caatinga and Atlantic Forest Biomes.

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.

Ex-vivo mucolytic and anti-inflammatory activity of BromAc in tracheal aspirates from COVID-19.

COVID-19 is a lethal disease caused by the pandemic SARS-CoV-2, which continues to be a public health threat. COVID-19 is principally a respiratory disease and is often associated with sputum retention and cytokine storm, for which there are limited therapeutic options. In this regard, we evaluated the use of BromAc®, a combination of Bromelain and Acetylcysteine (NAC). Both drugs present mucolytic effect and have been studied to treat COVID-19. Therefore, we sought to examine the mucolytic and anti-inflammatory effect of BromAc® in tracheal aspirate samples from critically ill COVID-19 patients requiring mechanical ventilation. METHOD: Tracheal aspirate samples from COVID-19 patients were collected following next of kin consent and mucolysis, rheometry and cytokine analysis using Luminex kit was performed. RESULTS: BromAc® displayed a robust mucolytic effect in a dose dependent manner on COVID-19 sputum ex vivo. BromAc® showed anti-inflammatory activity, reducing the action of cytokine storm, chemokines including MIP-1alpha, CXCL8, MIP-1b, MCP-1 and IP-10, and regulatory cytokines IL-5, IL-10, IL-13 IL-1Ra and total reduction for IL-9 compared to NAC alone and control. BromAc® acted on IL-6, demonstrating a reduction in G-CSF and VEGF-D at concentrations of 125 and 250 µg. CONCLUSION: These results indicate robust mucolytic and anti-inflammatory effect of BromAc® ex vivo in tracheal aspirates from critically ill COVID-19 patients, indicating its potential to be further assessed as pharmacological treatment for COVID-19.

Performance, meat quality, and lipidemia of meat-type quails fed with diets containing essential oils / Desempenho, qualidade da carne e lipidemia de codornas de corte alimentadas com rações contendo óleos essenciais

This study evaluated the effect of essential oil (ESOL) of Mentha piperita and Melaleuca alternifolia on meat-type quails. To examine performance, a completely randomized design was used, with four treatments and eight repetitions each, using seven birds per repetition. To assess lipidemia, a completely randomized design in a 4 × 2 factorial scheme was used, with four treatments and two collection conditions using eight repetitions and one bird per repetition. Weight gain, feed intake, feed conversion, carcass yield, cholesterol, high-density lipoporteins, triglycerides, pH, and brightness of quail breast meat were assessed. The data were analyzed for homoscedasticity and normality, and the means were subjected to analysis of variance. Adding M. piperita and M. alternifolia ESOL to the diets of meat-type quails can improve performance, carcass yield, and meat quality characteristics, comparable to the use of performance-enhancing antibiotics. The use of zinc bacitracin, M. piperita, and M. alternifolia under different collection conditions did not increase the serum levels of low-density and very low-density lipoproteins. The variation coefficients measured after 12 hours of fasting were 86% lower than without fasting.

Objetivou-se com este estudo avaliar o efeito do uso dos óleos essenciais (OLES) de Mentha piperita e Melaleuca alternifolia em codornas de corte. Para o estudo do desempenho foi utilizado o delineamento inteiramente ao acaso, com quatrotratamentos e oito repetições, sendo sete aves por repetição. Para o estudo da lipidemia utilizou-se o delineamento inteiramente casualizado em esquema fatorial: 4x2, consistindo em quatro tratamentos e duas condições de coleta, com oito repetições, sendo uma ave por repetição. As variáveis analisadas foram: ganho de peso, consumo ração, conversão alimentar, rendimento de carcaça, colesterol, HDL, triglicerídeos, pH, capacidade de retenção de água, perda de peso por cozimento, luminosidade na carne do peito de codornas. Os dados obtidos foram analisados quanto à homocedasticidade e normalidade, as médias foram submetidas à análise de variância. O uso de OLES de M. piperita e M. alternifolia na dieta de codornas de corte pode proporcionar desempenhos zootécnicos, rendimentos de carcaça e características de qualidade da carne comparáveis ao uso de antibióticos melhoradores de desempenho. A redução no nível de colesterol HDL foi notada nas aves tratadas com Bacitracina de zinco e com os OLES de M. piperita e M. alternifolia, em 8,12; 16,52 e 3,36% respectivamente. O uso da Bacitracina de zinco, da M. piperita e da M. alternifolia associado às diferentes condições de coleta não aumentaram os valores séricos de LDL, VLDL. Os coeficientes de variação aferidos na condição "após 12 horas de jejum" apresentaram-se 86% inferiores à condição "sem jejum".

Characteristics and Factors Associated with SARS-CoV-2 Infections in Individuals That Attended Referral Hospitals from Southern Region of Bahia State, Brazil: A Surveillance Network Retrospective Study.

In December 2019, a novel coronavirus was detected in Wuhan, China, and rapidly spread worldwide. In Brazil, to date, there have been more than 20,000,000 confirmed cases of COVID-19 and more than 550,000 deaths. The purpose of the current study was to determine the clinical and epidemiological profile of the population affected by COVID-19 that have attended referral hospitals in Southern region of Bahia State, to better understand the disease and its risk factors in order to enable more appropriate conduct for patients. An observational, descriptive, cross-sectional, exploratory study was conducted using secondary data collected from the Laboratório de Farmacogenômica e Epidemiologia Molecular, Universidade Estadual de Santa Cruz (LAFEM/UESC). Chi-squared and Fisher's exact tests were applied to determine the association between clinical symptoms and laboratory results, and to identify risk factors associated with SARS-CoV-2 infection. A total of 3135 individuals with suspected severe respiratory illness were analyzed and 41.4% of them tested positive for SARS-CoV-2 infection. Male individuals and having comorbidities were risk factors significantly associated with SARS-CoV-2 infection (OR = 1.17 and OR = 1.37, respectively). Interestingly, being a healthcare professional was a significantly protective factor (OR = 0.81, p < 0.001). Our findings highlight the importance of routinely testing the population for early identification of infected individuals, and also provide important information to health authorities and police makers to improve control measures, management, and screening protocols.

Genomic surveillance of SARS-CoV-2 tracks early interstate transmission of P.1 lineage and diversification within P.2 clade in Brazil.

The sharp increase of COVID-19 cases in late 2020 has made Brazil the new epicenter of the ongoing SARS-CoV-2 pandemic. The novel viral lineages P.1 (Variant of Concern Gamma) and P.2, respectively identified in the Brazilian states of Amazonas and Rio de Janeiro, have been associated with potentially higher transmission rates and antibody neutralization escape. In this study, we performed the whole-genome sequencing of 185 samples isolated from three out of the five Brazilian regions, including Amazonas (North region), Rio Grande do Norte, Paraíba and Bahia (Northeast region), and Rio de Janeiro (Southeast region) in order to monitor the spread of SARS-CoV-2 lineages in Brazil in the first months of 2021. Here, we showed a widespread dispersal of P.1 and P.2 across Brazilian regions and, except for Amazonas, P.2 was the predominant lineage identified in the sampled states. We estimated the origin of P.2 lineage to have happened in February, 2020 and identified that it has differentiated into new clades. Interstate transmission of P.2 was detected since March, but reached its peak in December, 2020 and January, 2021. Transmission of P.1 was also high in December and its origin was inferred to have happened in August 2020. We also confirmed the presence of lineage P.7, recently described in the southernmost region of Brazil, to have spread across the Northeastern states. P.1, P.2 and P.7 are descended from the ancient B.1.1.28 strain, which co-dominated the first phase of the pandemic in Brazil with the B.1.1.33 strain. We also identified the occurrence of a new lineage descending from B.1.1.33 that convergently carries the E484K mutation, N.9. Indeed, the recurrent report of many novel SARS-CoV-2 genetic variants in Brazil could be due to the absence of effective control measures resulting in high SARS-CoV2 transmission rates. Altogether, our findings provided a landscape of the critical state of SARS-CoV-2 across Brazil and confirm the need to sustain continuous sequencing of the SARS-CoV-2 isolates worldwide in order to identify novel variants of interest and monitor for vaccine effectiveness.

First genome sequencing of SARS-CoV-2 recovered from an infected cat and its owner in Latin America.

An 11-year-old male mixed-breed cat, with exclusively indoor life, presented 3 cough episodes after the owners tested positive by RT-PCR for SARS-CoV-2. The house is inhabited by 5 people (3 adults and 2 children), and 2 of the adults have shown mild symptoms associated with throat discomfort. The cat was vaccinated, had no history of any previous disease, and tested negative for feline coronavirus (FCoV), feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV). Rectal sample collected from the cat was positive for SARS-CoV-2 by RT-PCR. Viral genome sequences recovered from human and cat samples showed an average 99.4% sequence identity. This is the first report of genome sequences of SARS-CoV-2 recovered from a cat and its owner in Latin America.

Salmonella spp. in Wild Free-Living Birds from Atlantic Forest Fragments in Southern Bahia, Brazil.

Wild animals have an ecological function and can serve as sentinels to identify infectious agents and as indicators of environmental health. Among the zoonotic pathogens, Salmonella spp. deserve special attention due to their high worldwide prevalence and their ubiquity of hosts. With the aim of investigating the presence of Salmonella spp. in wild birds from the Atlantic Forest in southern Bahia, Brazil, we collected 114 fecal samples of wild birds (14 families) between 2016 and 2017. Fecal samples were collected by means of cloacal swab and subjected to microbiological culture to isolate and serotype Salmonella spp. specifically. Antibiotic susceptibility was determined using the disk diffusion test protocol. Only one bird, Ceratopipra rubrocapilla, tested positive for Salmonella enterica subsp. enterica serotype Agona, which is the first record for this bird species. This isolate exhibited intermediate sensitivity to amikacin and gentamicin and sensitivity to the other 13 antibiotics tested. Results may indicate environmental preservation since the studied areas had minimal human activity and good sanitary quality. Despite the low prevalence, it is necessary to monitor wildlife and establish disease control and surveillance systems, especially for zoonotic diseases.

Multiplex Real-Time Polymerase Chain Reaction for Simultaneous Quantification of Salmonella spp., Escherichia coli, and Staphylococcus aureus in Different Food Matrices: Advantages and Disadvantages.

Quantitative real-time polymerase chain reactions (qPCRs) of the most prevalent bacteria causing foodborne diseases worldwide, such as Salmonella spp., Escherichia coli, and Staphylococcus aureus, can be an important tool for quantitative microbial risk assessment, which requires numerical data to determine the level of contamination at a specific stage of food production. However, most of qPCR assays described in the literature for these pathogens are qualitative; their objective is pathogen detection and not pathogen quantification. Thus, the aim of our work was to develop a qPCR for the simultaneous quantification of Salmonella spp., E. coli, and S. aureus and to propose its use in the analysis of foods, as a tool for microbiological quality monitoring. For this, a multiplex qPCR was standardized for the simultaneous quantification of specific fragments of target genes (ssf, phoA, and nuc) corresponding to each one of the mentioned bacteria. The limit of detection of the technique was 13, 10, and 12 gene copies for ssf, phoA, and nuc, respectively; standard curves showed R2 > 0.99, with efficiencies ranging from 99 to 110%, and inter- and intraexperiment reproducibility presented a low coefficient of variation in all trials. This methodology was applied in different food matrices (milk, ground beef, and oyster meat), and the results were compared with official microbiological culture methodology and with ready-to-use test. Advantages and disadvantages of each methodology used in this study are pointed out. We suggest that this multiplex qPCR can be used as a rapid screening technique for the analysis of food microbiological quality.

Application of multiplex real-time polymerase chain reaction assay for simultaneous quantification of Escherichia coli virulence genes in oysters.

Strains of diarrheagenic Escherichia coli (DEC) are involved in foodborne disease outbreaks worldwide, especially the enterohemorrhagic E. coli O157:H7. This study describes two multiplex quantitative real time PCR (qPCR) assays for simultaneous identification and quantification of genes related to virulence of DEC; a triplex reaction for detection and quantification of stxA1, stxA2, and eaeA genes, and a duplex reaction for detection and quantification of eaeA and virA genes. The technique was applied in raw oyster samples for direct quantification of DEC, thereby evaluating the applicability of this methodology for microbiological quality assessment of food. Using custom designed primers and specific MGB probes, a triplex qPCR assay was performed to quantify stxA1, stxA2, and eaeA, and a duplex reaction was performed to quantify virA and eaeA genes. The assays showed high sensitivity, with the detection limit varying between 5 and 17 copies of the genes. The coefficient of determination (R2) of the standard curves was 0.99. The coefficient of variation was < 1% indicated high intra- and inter-assay reproducibilities. The application of this methodology in oyster samples from tropical environment provided direct quantitative data that determined the presence of the genes stxA1 (32.1%), eaeA (28.6%), stxA2 (3.6%), and virA (3.6%). This would prove critical for immediate intervention of control strategies, particularly in oysters that are often ingested as raw food.

Isolation and Genotyping of Toxoplasma gondii in Brazilian Dogs.

Strains of Toxoplasma gondii in Brazil are highly genetically diverse compared to strains from North America and Europe. Dogs are epidemiologically important because they act as sentinels for T. gondii infections in humans and are good indicators of environmental contamination. The aim of this study was to isolate and genetically characterize T. gondii strains from tissues of naturally infected Brazilian dogs. For this study, 21 blood samples were collected from dogs at the Zoonosis Control Centers of Ilhéus and Itabuna cities, Bahia, Brazil. The sera were examined for T. gondii antibodies using the indirect hemagglutination test. Brains and hearts of seropositive dogs were bioassayed in mice to isolate and characterize T. gondii parasites by PCR-RFLP using 10 genetic markers (SAG1, newSAG2, SAG3, BTUB, c22-8, c29-2, GRA6, PK1, APICO, and L358). However, T. gondii was isolated from only 4 (57.1%) dogs, designated TgDgBr6, 13, 17, and 21. All strains were virulent, causing clinical changes (rough hair coat, lethargy, and abdominal distention) and the death of all mice within 8-20 days after inoculation. Genetic analysis of these 4 T. gondii isolates revealed 4 distinct genotypes with different clonal lineage combinations (types I, II, and III) and 2 atypical alleles. Using PCR-RFLP with several markers, this study contributes to evaluations of the genetic diversity of strains circulating in Brazil.

The role of cytokines in immune regulation of female reproductive physiology

Cytokines act as protein mediators of the immune system and exert pleiotropic effects on the source cells and/or on target cells. Cytokines are formed in a cascade, bind to specific receptors, and influence the activity, differentiation, proliferation, and survival of immune cells of both T helper 1 (Th1) type (which has proinflammatory properties) and Th2 type (with an anti-inflammatory function). The female reproductive system is regulated by the immune system via cytokines at various physiological stages: during the ovarian cycle, maternal recognition, embryo implantation, gestation, and birth, participating in homeostasis and protection from pathogens. These processes interact under the hormonal influence of the hypothalamic­pituitary­gonadal axis. This review is aimed at addressing the involvement of some cytokines in female reproductive physiology, highlighting the maternal recognition of the embryo and implantation as immunologically important steps for fetal survival. The scientific knowledge on the role of cytokines in female reproduction processes, such as the Th1/Th2 balance and immune tolerance should advance the research in various fields of assisted reproduction in humans and animals, such as artificial insemination, embryo transfer, and in vitro fertilization. The same is true for the development of contraceptive methods and understanding of pathological processes such as uterine infections and autoimmune diseases.

Identification and discrimination of Toxoplasma gondii, Sarcocystis spp., Neospora spp., and Cryptosporidium spp. by righ-resolution melting analysis.

The objective of this study was to standardize the high-resolution melting method for identification and discrimination of Toxoplasma gondii, Sarcocystis spp., Neospora spp., and Cryptosporidium spp. by amplification of 18S ribosomal DNA (rDNA) using a single primer pair. The analyses were performed on individual reactions (containing DNA from a single species of a protozoan), on duplex reactions (containing DNA from two species of protozoa in each reaction), and on a multiplex reaction (containing DNA of four parasites in a single reaction). The proposed method allowed us to identify and discriminate the four species by analyzing the derivative, normalized, and difference melting curves, with high reproducibility among and within the experiments, as demonstrated by low coefficients of variation (less than 2.2% and 2.0%, respectively). This is the first study where this method is used for discrimination of these four species of protozoa in a single reaction.

Microbiological Quality and Prevalence of ß-Lactam Antibiotic Resistance Genes in Oysters ( Crassostrea rhizophorae ).

The microbiological quality of oysters reflects the microbiological quality of their habitats because they are filter feeders. The objective of this study was to assess the bacterial composition of the edible oyster Crassostrea rhizophorae in urban and preserved estuaries. Particularly, we assessed the presence of pathogenic bacteria, investigated antibiotic susceptibility in bacterial isolates, and quantified ß-lactam antibiotic resistance genes (blaTEM, blaSHV, and blaKPC) via quantitative PCR of oyster DNA. Our results detected total coliforms, Escherichia coli , and enterobacteria in the oysters from urban estuaries, which is indicative of poor water quality. In addition, our detection of the eaeA and stxA2 virulence genes in 16.7% of E. coli isolates from oysters from this region suggests the presence of multiantibiotic-resistant enteropathogenic and enterohemorrhagic E. coli strains. During periods of low precipitation, increased contamination by E. coli (in winter) and Vibrio parahaemolyticus (in autumn) was observed. In contrast, cultivated oysters inhabiting monitored farms in preserved areas had low levels of bacterial contamination, emphasizing that oyster culture monitoring enhances food quality and makes oysters fit for human consumption. Distinct antibiotic resistance profiles were observed in bacteria isolated from oysters collected from different areas, including resistance to ß-lactam antibiotics. The presence of the blaTEM gene in 91.3% of oyster samples indicated that microorganisms in estuarine water conferred the capability to produce ß-lactamase. To our knowledge, this is the first study to directly quantify and detect ß-lactam antibiotic resistance genes in oysters. We believe our study provides baseline data for bacterial dynamics in estuarine oysters; such knowledge contributes to developing risk assessments to determine the associated hazards and consequences of consuming oysters from aquatic environments containing pathogenic bacteria that may possess antibiotic resistance genes.

Identification and genetic characterization of Toxoplasma gondii in free-ranging bristle-spined porcupine (Chaetomys subspinosus), a threatened arboreal mammal from the Brazilian Atlantic Forest.

BACKGROUND: Strains of Toxoplasma gondii in Brazil have high genetic diversity compared to North America and Europe. The bristle-spined porcupine, Chaetomys subspinosus, is often subject to hunting for human food, but it is not known whether it can be a reservoir of this parasite. The aim of this study was to verify the occurrence of T. gondii in C. subspinosus from southern Bahia, Brazil, and genetically characterize and compare the strains found with those isolated in previous studies of the same region to quantify their genetic diversity by multilocus PCR-RFLP and PCR sequencing. FINDINGS: Twelve free-ranging C. subspinosus captured in forest fragments of the Una Biological Reserve and adjacent areas were evaluated. Three isolates of T. gondii (TgCsBr01-03) were detected. Two different genotypes were identified by applying multilocus PCR-RFLP with six molecular markers (SAG1, SAG2, SAG3, c22-8, PK1, and Apico). The isolates TgCsBr02 and TgCsBr03 were indistinguishable by this technique. However, the three isolates differed from all the reference strains and from the samples from the same region. Nevertheless, when the six genetic markers were used in multilocus PCR sequencing, all three isolates of T. gondii were different. The phylogenetic analysis revealed a greater genetic distance for TgCsBr01, which was closer to isolates from pigs from the same region, while TgCsBr02-03 was classified in the same lineage and was closer to isolates from sheep from this region. CONCLUSIONS: All the isolates differed from the clonal genotypes of types I, II, and III using both genotyping techniques.

Infection cycle of Salmonella enterica serovar Enteritidis in latent carrier mice.

This work reports the distribution of an oral dose of Salmonella enterica serovar Enteritidis (SE) in C57Bl/6-Bcgr mice, to study its pathogenesis in a latent carrier animal. Mice orally inoculated with a high dose of SE developed a latent infection characterized by the absence of clinical symptoms in which the cecum is functioning as a "strategic site" of SE proliferation, releasing bacteria into feces intermittently over the 4-week study. A sequence of disruptions occurred in the small intestine at 1 day postinculation (PI). The microvilli exhibited different degrees of degeneration, which were reversible as the cells became vacuolated. From 2 days PI, SE was detected in the mononuclear phagocytic system, and an exponential growth of the remaining bacteria in tissues was observed until 4 days PI. The production of interferon gamma from 3 days PI is restricting the SE growth, and a plateau phase was observed from 4 to 15 days PI. A recurrence of the bacterial growth in tissue occurred from 15 to 28 days PI, especially in the cecum. Increasing our knowledge about the host-pathogen interaction of adapted pathogens with the ability to develop latency is essential for the development of an efficient strategy for Salmonella control.

Microbial surfactant activities from a petrochemical landfarm in a humid tropical region of Brazil.

The goal of this study was to assess the presence and surfactant potential of naturally occurring microbes from a tropical soil with petrochemical contamination. Microorganisms in a soil sample from a Brazilian landfarm were isolated and grown on petroleum as the sole carbon source. Of 60 isolates screened for petroleum-based growth, 7 demonstrated surfactant activities by the drop-collapse methodology over various types of oils. From their growth profiles in liquid culture during 132 h, all had their first detection of surfactant activity after 96 h. Little is currently known about biosurfactant-producing microorganisms in tropical environments contaminated by hydrophobic compounds, and the search for them is essential for bioremediation and for oil recovery enhanced by microbes. Our results indicate that different petroleum-grown microorganisms showing surfactant activity can be recovered from landfarm soil in a tropical environment.

Ocorrência de sorotipos exóticos de Salmonella encontrados em cães assintomáticos nos distritos do município de Ilhéus / BA - Brasil / Occurrence of exotic Salmonella serovar in assymptomatic dogs in Ilheus City / BA - Brazil

Amostras fecais de cães provenientes de distritos carentes do Município de Ilhéus / BA foram analisadas para a presença de Salmonella spp durante o período de junho de 2001 a abril de 2002. Dezoito (9,47 por cento) dos 190 animais foram considerados positivos sendo que 66,6 por cento destes casos ocorreram com animais até 1 ano de idade, 56 por cento se alimentavam com comida caseira, 66 por cento tinham acesso à fonte de água não tratada e 67 por cento possuía comportamento domiciliar. A sintomatologia da doença não foi percebida em 83,3 por cento dos animais. A S. Gafsa representou o sorotipo mais prevalente (38,9 por cento), seguido pela S. Rubislaw (27,8), S. Carrau (16,7 por cento) e S. enterica subsp. Houtenae (11,1 por cento). Uma cepa não pôde ser identificada. O antibiograma revelou a gentamicina como sendo a droga mais potente, in vitro, para o tratamento das salmonelas encontradas na região de Ilhéus, seguida pela ampicilina. Nossos resultados confirmam que cães representam um importante reservatório de sorotipos exóticos de Salmonella e que ocorre padrões diferentes de sensibilidade a antibióticos entre eles.