Genomic features and heat resistance profiles of Escherichia coli isolated from Brazilian beef.

AIMS: Characterize Escherichia coli and E. coli -producing (STEC) isolates from Brazilian beef to determine heat resistance and the presence of the transmissible locus of stress tolerance (tLST). METHODS AND RESULTS: Twenty-two STEC previously isolated from beef and characterized as STEC by PCR were subjected to different heat survival challenges (60°C and 71°C). Furthermore, the three tLST-positive isolates and one tLST-negative isolate by PCR were selected for WGS analysis. Phenotypic results indicated that 3/22 (13.64%) were heat resistant, 12/22 (54.54%) were moderately resistant, and 7/22 (31.82%) were sensitive to heat treatments. WGS analyses showed that three isolates with heat resistance showed tLST with up to 80% and 42% of similarity by BLAST analysis, with the major tLST genes being responsible for the homeostasis module. However, WGS showed the absence of stx genes associated with tLST-positive isolates, albeit with virulence and resistance genes found in extraintestinal pathogenic E. coli (ExPEC). CONCLUSION: Our findings demonstrate the presence of heat-resistant E. coli as well as confirm some tLST genes in E. coli isolated from Brazilian beef.

Antimicrobial Resistance of Listeria monocytogenes from Animal Foods to First- and Second-Line Drugs in the Treatment of Listeriosis from 2008 to 2021: A Systematic Review and Meta-Analysis.

First-line drugs for the treatment of listeriosis are the same around the world, but particular conditions might reduce their efficacy, including antimicrobial resistance. Therefore, this study aimed to verify, based on a systematic review and meta-analysis, whether the prevalence of antimicrobial resistance in Listeria monocytogenes from animal foods is higher for first- or second-line antimicrobials. From the total of 302 identified studies, 16 met all the eligibility criteria from 2008 to 2021 and were included in this meta-analysis. They comprised a dataset of 1152 L. monocytogenes isolates, obtained from different animal food products, food processing environment, and live animals. The included studies were developed in South America (n = 5), Europe (n = 4), Asia (n = 3), Africa (n = 2), and North America (n = 2), testing a total of 35 different antimicrobials, 11 of them classified as first-line drugs. Complete lack of antimicrobial resistance across the studies (all L. monocytogenes isolates tested as susceptible) was only observed for linezolid, while widespread antimicrobial resistance (all L. monocytogenes isolates tested resistant) was described for amoxicillin, benzylpenicillin, cefoxitin, fusidic acid, imipenem, sulfamethoxazole, and vancomycin. Overall, the meta-analysis results indicated no evidence that antimicrobial resistance in L. monocytogenes isolated from animal-based food is higher for first-line antimicrobials compared to second-line compounds (p=0.37). A greater volume of publication, together with better characterization of the isolates, is still needed for a more precise estimate of the real prevalence of antimicrobial resistance in L. monocytogenes.

Salmonella in the processing line of farmed Tambatinga (Colossoma macropomum x Piaractus brachypomus) in Mato Grosso, Brazil: serotypes of occurrence and antimicrobial profile.

The objective of this study was to evaluate the dispersion dynamics and antimicrobial resistance profiles of Salmonella in the processing of Tambatinga (Colossoma macropomum x Piaractus brachypomus). Thirty fish were monitored during four processing stages (reception, first wash, evisceration, and prepackage area) in a fish slaughterhouse. One hundred and twenty fish surface samples were collected and tested through bacteriological analysis, PCR, serotyping, and antimicrobial resistance profile (disk-diffusion). Of these samples, 7.5% (9/120) were positive for Salmonella, with 0.83% being observed in the pre-packaging phase, indicating a low occurrence at this stage. All the analyzed stages were positive for Salmonella, with the prevalent serovars being Ndolo, Mbandaka, Typhimurium, Rough, and O:16. All strains were sensitive to various antimicrobials. Improvements in microbiological control during all processing stages should be implemented to ensure a Salmonella-free product.

Worldwide Epidemiology of Salmonella Serovars in Animal-Based Foods: a Meta-analysis.

Salmonella spp. are among the most important foodborne pathogens and the third leading cause of human death among diarrheal diseases worldwide. Animals are the primary source of this pathogen, and animal-based foods are the main transmission route to humans. Thus, understanding the global epidemiology of Salmonella serovars is key to controlling and monitoring this bacterium. In this context, this study aimed to evaluate the prevalence and diversity of Salmonella enterica serovars in animal-based foods (beef, pork, poultry, and seafood) throughout the five continents (Africa, the Americas [North and Latin America], Asia, Europe, and Oceania). The meta-analysis consisted of a chemometric assessment (hierarchical cluster analysis and principal component analysis) to identify the main epidemiological findings, including the prevalence and diversity of the Salmonella serovars in each matrix. Regarding the serovar distribution, S Typhimurium presented a cosmopolitan distribution, reported in all four assessed matrices and continents; poultry continues to play a central role in the dissemination of the Enteritidis serovar to humans, and Anatum and Weltevreden were the most frequently found in beef and seafood, respectively. Additionally, we recommended careful monitoring of certain serovars, such as Derby, Agona, Infantis, and Kentucky. Finally, given the scientific data regarding the most frequently reported serovars and which matrices constitute the main vehicles for the transmission of this pathogen, control programs may be improved, and specific interventions may be implemented in an attempt to reduce the risk of this pathogen reaching humans.IMPORTANCE Salmonellosis is caused by Salmonella spp. and is the third leading cause of death among food-transmitted diseases. This pathogen is commonly disseminated in domestic and wild animals, and the infection's symptoms are characterized by acute fever, nausea, abdominal pain, and diarrhea. The animals are the primary source of salmonellae, and animal-based foods are the main transmission route to humans. Therefore, data collected from these sources could contribute to future global interventions for effective control and surveillance of Salmonella along the food chain. In light of this, the importance of our research is in identifying the prevalence of Salmonella serovars in four animal-based food matrices (pork, poultry, beef, and seafood) and to evaluate the importance that each matrix has as the primary source of this pathogen to humans.

Acetic Acid Increased the Inactivation of Multi-drug Resistant Non-typhoidal Salmonella by Large-Scaffold Antibiotic.

Salmonella is a gram-negative bacterium with intrinsic resistance to large-scaffold antibiotics due to the presence of an outer membrane. Based on the mode of action of the organic acids in outer membrane disintegration, and consequently, an enhancement in cell permeability, a combination of acetic acid and a large-scaffold antibiotic is it evaluated. Therefore, the aim of this study is to assess the combination of different levels of acetic acid with vancomycin, in order to determine whether or not the organic acid may overcome the cell wall and the intrinsic resistance in multi-drug resistant Salmonella. Screening of five wild-type Salmonella strains and one clinical strain was performed to select the strain more resistance to acid inhibition. Acetic acid was tested at 2.0, 1.75, 1.50, and 1.25% levels, separated or combined with 8 µg/mL vancomycin dose. An aliquot was collected after exposure and inoculated into the brain and heart infusion agar. The plates were counted and the data analyzed by ANOVA and a posthoc Tukey test (p < 0.05). The results indicate that 1.25 and 1.50% levels did not affect the vancomycin inactivation of multi-drug resistant Salmonella. However, at levels of 1.75 and 2.0%, an increase in microbial reduction is observed. Also, 2% level acetic acid and vancomycin had a threefold increase compared to vancomycin alone. Therefore, the use of acetic acid as prior treatment for Salmonella increased the inactivation rate of vancomycin. The combination of organic acid and antibiotics is a potential tool to overcome cases of antimicrobial resistance.

Escherichia coli O26 and O113:H21 on Carcasses and Beef from a Slaughterhouse Located in Mato Grosso, Brazil.

Shiga toxin-producing Escherichia coli (STEC) is a group of emerging pathogens that can cause human diseases, including hemolytic uremic syndrome (HUS) and hemorrhagic colitis (HC). Monitoring slaughtering stages and checking contamination points are crucial for the production of safe food. In this context, the aim of this study was to verify contamination by STEC strains, to determine the contamination points and evaluate the resistance profile to 12 antimicrobials used in both veterinary and human medicine. A total of 80 samples were obtained from eight collection points (pen floor, rectum, hide, carcass swabs and esophagus, diaphragm, masseter, and retail beef tissue samples). The isolates were collected by dilution plating on MacConkey agar with sorbitol, cefixime, and tellurite and analyzed by multiplex polymerase chain reaction for virulence genes. Serotyping of non-O157 was performed, and testing for 12 antibiotics by disk diffusion was carried out. A total of 18 STEC strains were isolated, presenting different virulence profiles. Contamination by STEC was observed in the rectum (5/18), carcass surface (5/18), hide (3/18), diaphragm (2/18), retail beef (2/18), and masseter muscle (1/18). Pen floor swabs and esophagus tissues showed no STEC contamination. Moreover, three strains were identified as O26 and three as O113:H21 strains, which have been linked to HUS and HC outbreak cases in Brazil. All STEC isolates were susceptible to all evaluated antimicrobials, except streptomycin. The presence of STEC strains is a direct risk to the consumer, especially when isolated from retail beef, and contamination can occur during different slaughter stages. However, antimicrobial resistance profiles did not identify multidrug-resistant strains, limiting potential antimicrobial resistance transmission to other pathogens.

Listeria monocytogenes in beef: a hidden risk.

Listeria monocytogenes in beef receives less attention compared to other pathogens such as Salmonella and Escherichia coli. To address this gap, we conducted a literature review focusing on the presence of L. monocytogenes in beef. This review encompasses the pathogenic mechanisms, routes of contamination, prevalence rates, and the laws and regulations employed in various countries. Our findings reveal a prevalence of L. monocytogenes in beef and beef products ranging from 2.5% to 59.4%. Notably, serotype 4b was most frequently isolated in cases of beef contamination during food processing, with the skinning and evisceration stages identified as critical points of contamination.

Optimizing the Antimicrobial Activity of Sodium Hypochlorite (NaClO) over Exposure Time for the Control of Salmonella spp. In Vitro.

Fish is a nutritionally rich product; however, it is easily contaminated by pathogenic microorganisms, such as Salmonella spp. Therefore, this study aimed to identify the best concentration of sodium hypochlorite (NaClO), exposure time, and water temperature that allow the most effective antimicrobial effect on the viable population of Salmonella spp. Thus, Salmonella Enteritidis ATCC 13076 and Salmonella Schwarzengrund were exposed to different time frames, ranging from 5 min to 38.5 min, temperatures between 5 and 38.5 °C, and NaClO concentrations ranging from 0.36 to 6.36 ppm, through a central composite rotational design experiment (CCRD). The results demonstrated that the ATCC strain exhibited a quadratic response to sodium hypochlorite when combined with exposure time, indicating that initial contact would already be sufficient for the compound's action to inhibit the growth of the mentioned bacteria. However, for S. Schwarzengrund (isolated directly from fish cultivated in aquaculture), both NaClO concentration and exposure time significantly influenced inactivation, following a linear pattern. This suggests that increasing the exposure time of NaClO could be an alternative to enhance Salmonella elimination rates in fish slaughterhouses. Thus, the analysis indicates that the Salmonella spp. strains used in in vitro experiments were sensitive to concentrations equal to or greater than the recommended ones, requiring a longer exposure time combined with the recommended NaClO concentration in the case of isolates from aquaculture.

Heat-resistant and biofilm-forming Escherichia coli in pasteurized milk from Brazil.

Escherichia coli harboring a transmissible locus of stress tolerance (tLST) and the ability to form biofilms represent a serious risk in dairy production. Thus, we aimed to evaluate the microbiological quality of pasteurized milk from two dairy producers in Mato Grosso, Brazil, with a focus on determining the possible presence of E. coli with heat resistance (60 °C/6 min), biofilm-forming potential phenotypes and genotypes, and antimicrobial susceptibility. For this, fifty pasteurized milk samples from producers named A and B were obtained for 5 weeks to investigate the presence of Enterobacteriaceae members, coliforms, and E. coli. For heat resistance, E. coli isolates were exposed to a water bath at 60 °C for 0 and 6 min. In antibiogram analysis, eight antibiotics belonging to six antimicrobial classes were analyzed. The potential to form biofilms was quantified at 570 nm, and curli expression by Congo Red was analyzed. To determine the genotypic profile, we performed PCR for the tLST and rpoS genes, and pulsed-field gel electrophoresis (PFGE) was used to investigate the clonal profile of the isolates. Thus, producer A presented unsatisfactory microbiological conditions regarding Enterobacteriaceae and coliforms for weeks 4 and 5, while all samples analyzed for producer B were contaminated at above-the-limit levels established by national and international legislation. These unsatisfactory conditions enabled us to isolate 31 E. coli from both producers (7 isolates from producer A and 24 isolates from producer B). In this way, 6 E. coli isolates (5 from producer A and 1 from producer B) were highly heat resistant. However, although only 6 E. coli showed a highly heat-resistant profile, 97% (30/31) of all E. coli were tLST-positive. In contrast, all isolates were sensitive to all antimicrobials tested. In addition, moderate or weak biofilm potential was verified in 51.6% (16/31), and the expression of curli and presence of rpoS was not always related to this biofilm potential. Therefore, the results emphasize the spreading of heat-resistant E. coli with tLST in both producers and indicate the biofilm as a possible source of contamination during milk pasteurization. However, the possibility of E. coli producing biofilm and surviving pasteurization temperatures cannot be ruled out, and this should be investigated.

Increased interregional virus exchange and nucleotide diversity outline the expansion of the chikungunya virus ECSA lineage in Brazil.

The emergence and reemergence of mosquito-borne diseases in Brazil such as Yellow Fever, Zika, Chikungunya, and Dengue have had serious impacts on public health. Concerns have been raised due to the rapid dissemination of the chikungunya virus (CHIKV) across the country since its first detection in 2014 in Northeast Brazil. Faced with this scenario, on-site training activities in genomic surveillance carried out in partnership with the National Network of Public Health Laboratories have led to the generation of 422 CHIKV genomes from 12 Brazilian states over the past two years (2021-2022), a period that has seen more than 312 thousand chikungunya fever cases reported in the country. These new genomes increased the amount of available data and allowed a more comprehensive characterization of the dispersion dynamics of the CHIKV East-Central-South-African (ECSA) lineage in Brazil. Tree branching patterns revealed the emergence and expansion of two distinct subclades. Phylogeographic analysis indicated that the northeast region has been the leading hub of virus spread towards other regions. Increased frequency of C>T transitions among the new genomes suggested that host restriction factors from the immune system such as ADAR and AID/APOBEC deaminases might be driving CHIKV ECSA lineage genetic diversity in Brazil.

Increased interregional virus exchange and nucleotide diversity outline the expansion of chikungunya virus in Brazil.

The emergence and reemergence of mosquito-borne diseases in Brazil such as yellow fever, zika, chikungunya, and dengue have had serious impacts on public health. Concerns have been raised due to the rapid dissemination of the chikungunya virus across the country since its first detection in 2014 in Northeast Brazil. In this work, we carried out on-site training activities in genomic surveillance in partnership with the National Network of Public Health Laboratories that have led to the generation of 422 chikungunya virus genomes from 12 Brazilian states over the past two years (2021-2022), a period that has seen more than 312 thousand chikungunya fever cases reported in the country. These genomes increased the amount of available data and allowed a more comprehensive characterization of the dispersal dynamics of the chikungunya virus East-Central-South-African lineage in Brazil. Tree branching patterns revealed the emergence and expansion of two distinct subclades. Phylogeographic analysis indicated that the northeast region has been the leading hub of virus spread towards other regions. Increased frequency of C > T transitions among the new genomes suggested that host restriction factors from the immune system such as ADAR and AID/APOBEC deaminases might be driving the genetic diversity of the chikungunya virus in Brazil.

Application of serial analysis of gene expression to the study of the gene expression profile of Leishmania infantum chagasi promastigote.

This study describes the application of the LongSAGE methodology to study the gene expression profile in promastigotes of Leishmania infantum chagasi. A tag library was created using the LongSAGE method and consisted of 14,208 tags of 17 bases. Of these, 8,427 (59.3%) were distinct. BLAST research of the 1,645 most abundant tags showed that 12.8% of them identified the coding sequences of genes, while 82% (1,349/1,645) identified one or more genomic sequences that did not correspond with open reading frames. Only 5.2% (84/1,645) of the tags were not aligned to any position in the L. infantum genome. The UTR size of Leishmania and the lack of CATG sites in some transcripts were decisive for the generation of tags in these regions. Additional analysis will allow a better understanding of the expression profile and discovering the key genes in this life cycle.

Listeria monocytogenes and Pseudomonas spp. Distribution in a Processing Facility of Spotted Sorubim (Pseudoplatystoma corruscans) in Brazil.

ABSTRACT: The ecology of Listeria monocytogenes and Pseudomonas spp. during the slaughtering of spotted sorubim (Pseudoplatystoma corruscans) in a fish processing facility was assessed. Fish samples (n = 28) were obtained in different points of slaughtering (A, arrival; B, washing; C, gutting; and D, cooling) and subjected to detection of L. monocytogenes and enumeration of Pseudomonas spp. High frequencies of Listeria spp. (17 of 28 to 22 of 28) and L. monocytogenes (6 of 28 to 9 of 28) were identified in all slaughtering points but were not significantly different (P ≥ 0.05). All L. monocytogenes isolates (n = 33) were identified as belonging to serogroup IVb (serotype 4b) and subjected to macrorestriction with ApaI and AscI. The results indicated a continuous entry of L. monocytogenes in the facility, as well as a temporary persistence of a specific pulsotype. Pseudomonas spp. counts significantly decreased between points A and D (P < 0.05), but the mean counts in the end products (D) remained higher than 3 log CFU/g, suggesting the potential for fast spoilage. The obtained results show that L. monocytogenes and Pseudomonas spp. are widely distributed during spotted sorubim slaughtering, indicating the need for proper hygienic procedures to control these bacteria in the processing facility.

Salmonella spp. in Aquaculture: An Exploratory Analysis (Integrative Review) of Microbiological Diagnoses between 2000 and 2020.

The present study aimed to characterize, through descriptive statistics, data from scientific articles selected in a systematic integrative review that performed a microbiological diagnosis of Salmonella spp. in aquaculture. Data were obtained from research articles published in the BVS, Scielo, Science Direct, Scopus and Web of Science databases. The selected studies were published between 2000 and 2020 on samples of aquaculture animal production (fish, shrimp, bivalve mollusks, and other crustaceans) and environmental samples of aquaculture activity (farming water, soil, and sediments). After applying the exclusion criteria, 80 articles were selected. Data such as country of origin, categories of fish investigated, methods of microbiological diagnosis of Salmonella spp., sample units analyzed and most reported serovars were mined. A textual analysis of the word cloud and by similarity and descending hierarchical classification with the application of Reinert's algorithm was performed using R® and Iramuteq® software. The results showed that a higher percentage of the selected articles came from Asian countries (38.75%). Fish was the most sampled category, and the units of analysis of the culture water, muscle and intestine were more positive. The culture isolation method is the most widespread, supported by more accurate techniques such as PCR. The most prevalent Salmonella serovars reported were S. Typhimurium, S. Weltevreden and S. Newport. The textual analysis showed a strong association of the terms "Salmonella", "fish" and "water", and the highest hierarchical class grouped 25.4% of the associated text segments, such as "aquaculture", "food" and "public health". The information produced characterizes the occurrence of Salmonella spp. in the aquaculture sector, providing an overview of recent years. Future research focusing on strategies for the control and prevention of Salmonella spp. in fish production are necessary and should be encouraged.

Salmonella Schwarzengrund, Akuafo, and O:16 isolated from vacuum-packaged beef produced in the state of Mato Grosso, Brazil.

INTRODUCTION: Salmonella spp. is a pathogen associated with foodborne infections, mainly in foods of animal origin. In this context, the present study investigated the occurrence of Salmonella serotypes, genotypes and the antimicrobial resistance profiles of strains in fresh beef produced in Mato Grosso, Brazil. METHODOLOGY: A total of 107 samples from 13 different slaughterhouses in the Mato Grosso were analyzed. Suggestive Salmonella spp. colonies detected during the biochemical screening were submitted to DNA extraction, and hilA gene amplification was used for the PCR reaction. Antimicrobial resistance analyses were performed using 17 antimicrobial agents from eight different classes by the disk diffusion method. Strains exhibiting multiple drug resistances were submitted to PCR genotyping based on repetitive sequences (rep-PCR), using a commercial semiautomatic DiversiLab® system. RESULTS: A total of 5.6% (6/107) of the samples tested positive by the conventional method and were confirmed by PCR, namely two S. Akuafo, two non-typable Salmonella enterica strains, one Salmonella O:16 serovar, and one S. Schwarzengrund. The antimicrobial resistance profiles indicated resistance to gentamicin (30%), tetracycline, nitrofurantoin, and trimethoprim + sulfamethoxazole (16%). Genotyping indicated a 70% difference between S. Schwarzengrund and the non-typable Salmonella strains. No genetic similarities were observed between the six Salmonella isolates based on rep-PCR, including two S. Akuafo. CONCLUSIONS: The results obtained herein corroborate that Salmonella serovar Schwarzengrund is commonly isolated in animal products in the state of Mato Grosso, Brazil, also highlighting the presence of two unusual Salmonella serovars in beef (Akuafo and O:16).

Inactivation of Multi-Drug Resistant Non-Typhoidal Salmonella and Wild-Type Escherichia coli STEC Using Organic Acids: A Potential Alternative to the Food Industry.

Salmonella and Escherichia coli are the main bacterial species involved in food outbreaks worldwide. Recent reports showed that chemical sanitizers commonly used to control these pathogens could induce antibiotic resistance. Therefore, this study aimed to describe the efficiency of chemical sanitizers and organic acids when inactivating wild and clinical strains of Salmonella and E. coli, targeting a 4-log reduction. To achieve this goal, three methods were applied. (i) Disk-diffusion challenge for organic acids. (ii) Determination of MIC for two acids (acetic and lactic), as well as two sanitizers (quaternary compound and sodium hypochlorite). (iii) The development of inactivation models from the previously defined concentrations. In disk-diffusion, the results indicated that wild strains have higher resistance potential when compared to clinical strains. Regarding the models, quaternary ammonium and lactic acid showed a linear pattern of inactivation, while sodium hypochlorite had a linear pattern with tail dispersion, and acetic acid has Weibull dispersion to E. coli. The concentration to 4-log reduction differed from Salmonella and E. coli in acetic acid and sodium hypochlorite. The use of organic acids is an alternative method for antimicrobial control. Our study indicates the levels of organic acids and sanitizers to be used in the inactivation of emerging foodborne pathogens.

Listeria monocytogenes in Export-approved Beef from Mato Grosso, Brazil: Prevalence, Molecular Characterization and Resistance to Antibiotics and Disinfectants.

The Brazilian state of Mato Grosso is the largest producer and exporter of beef in the country, but few studies of relevance have been conducted to evaluate the microbiological safety of its products. This study aimed to estimate the prevalence of Listeria monocytogenes (LM) in export-approved beef from Mato Grosso and to characterize the isolates in terms of molecular properties and antimicrobial resistance. From a total of 50 samples analyzed, Listeria sp. was isolated in 18 (36% prevalence). Listeria monocytogenes was confirmed in 6 (12% prevalence). Among the serotype groups assessed by multiplex PCR, serotype 4 (4b, 4d or 4e) was the most prevalent. Although antibiotic resistance was not an issue, two strains isolated from different plants showed high resistance to sodium hypochlorite. Overall, this scenario causes concern because it puts at risk not only the Brazilian customer, but also the population of countries that import beef from Mato Grosso.

Mixture design approach for the development of reduced fat lamb patties with carboxymethyl cellulose and inulin.

Fat replacement by carboxymethyl cellulose (CMC) and inulin (IN) for the manufacture of low-fat lamb patties was investigated utilizing mixture design. The effect of fat, CMC, and IN levels on texture, color, weight loss, patty diameter reduction, and sensory characteristics was investigated. The presence of CMC decreased hardness (p < 0.05). While CMC and IN also decreased springiness, cohesiveness, gumminess, and chewiness (p < 0.05), no effect on adhesiveness was observed (p > 0.05). CMC increased L* (lightness), a* (redness), and b* (yellowness) values in raw patties, whereas IN and fat contributed to a decrease on these parameters. Higher contents of CMC resulted in products with lower weight loss (p < 0.05) with no significative diameter reduction (p > 0.05). Nonetheless, higher levels of CMC affected the sensory acceptance resulting on products described as crumbly and with residual flavor by check-all-that-apply questions. CMC and IN can be used as fat replacers in lamb patties; however, the content of each ingredient must be carefully considered. In this study, it was observed that contents of CMC higher than 1% (w/w) negatively affected the product, whereas IN levels were not capable to decrease weight loss and diameter reduction in lamb patties.

Eficácia da ivermectina e atazanavir no tempo de recuperação dos sintomas de covid-19: uma coorte prospectiva / Effectiveness of ivermectin and atazanavir on time to resolution from covid-19 symptoms: a prospective cohort / Eficacia de ivermectina y atazanavir en el tiempo hasta lá resolución de los síntomas de covid-19: una cohorte prospectiva

Objetivo: avaliar a eficácia da Ivermectina e do Atazanavir em comparação com placebo no tempo de resolução dos sintomas e no tempo de duração da doença por COVID-19. Método: estudo observacional, de coorte prospectivo, longitudinal, descritivo e analítico com pacientes sintomáticos ambulatoriais, acompanhados por 06 meses em duas Unidades Básicas de Saúde para atendimento de COVID-19 em Teresina- Piauí, Brasil, no período de novembro a abril de 2021 identificados por amostragem aleatória 1:1:1. Foram realizados exames Reverse transcription polymerase chain reaction (RT-PCR) para confirmação laboratorial da suspeita de infecção pelo novo coronavírus e avaliação sociodemográfica e clínica. Resultados: dos 87 pacientes randomizados, 62,1% (n=54) eram do sexo masculino, com média de idade de 35,1 anos, possuíam companheira (53,9%), baixa renda (50,6%), eutróficos (40,7%) e sem comorbidades de saúde (78,2%). Não houve diferença entre o tempo médio para resolução dos sintomas, que foi de 21 dias (IQR, 8-30) no grupo atazanavir, 30 dias (IQR, 5-90) no grupo ivermectina em comparação com 14 dias (IQR, 9-21) no grupo controle. No dia 180, houve resolução dos sintomas em 100% no grupo placebo, 93,9% no grupo atazanavir e 95% no grupo ivermectina. A duração mediana da doença foi de 08 dias em todos os braços do estudo. Conclusão: o tratamento com atazanavir (6 dias) e ivermectina (3 dias) não reduziu o tempo de resolução dos sintomas e nem o tempo de duração da doença entre os pacientes ambulatoriais com COVID-19 leve em comparação com o grupo placebo. Os resultados não suportam o uso de ivermectina e atazanavir para tratamento de COVID-19 leve a moderado.

Objective: to evaluate the effectiveness of Ivermectin and Atazanavir compared to placebo in the time to resolution of symptoms and duration of illness due to COVID-19. Method: observational, prospective, longitudinal, descriptive and analytical cohort study with symptomatic outpatients, followed for 06 months in two Basic Health Units for COVID-19 care in Teresina-Piauí, Brazil, from November to April 2021 identified by 1:1:1 random sampling. Reverse transcription polymerase chain reaction (RT-PCR) tests were performed for laboratory confirmation of suspected infection with the new coronavirus and sociodemographic and clinical evaluation. Results: of the 87 randomized patients, 62.1% (n=54) were male, with a mean age of 35.1 years, had a partner (53.9%), low income (50.6%), eutrophic (40.7%) and without health comorbidities (78.2%). There was no difference between the median time to resolution of symptoms, which was 21 days (IQR, 8-30) in the atazanavir group, 30 days (IQR, 5- 90) in the ivermectin group compared with 14 days (IQR, 9- 21) in the control group. At day 180, there was resolution of symptoms in 100% in the placebo group, 93.9% in the atazanavir group, and 95% in the ivermectin group. The median duration of illness was 8 days in all study arms. Conclusion: Treatment with atazanavir (6 days) and ivermectin (3 days) did not reduce the time to symptom resolution or the duration of illness among outpatients with mild COVID-19 compared to the placebo group. The results do not support the use of ivermectin and atazanavir for the treatment of mild to moderate COVID-19.

Objetivo: evaluar la efectividad de Ivermectina y Atazanavir en comparación con placebo en el tiempo de resolución de los síntomas y duración de la enfermedad por COVID-19. Método: estudio de cohorte observacional, prospectivo, longitudinal, descriptivo y analítico con pacientes ambulatorios sintomáticos, seguidos durante 06 meses en dos Unidades Básicas de Salud para atención de COVID-19 en Teresina-Piauí, Brasil, de noviembre a abril de 2021 identificados por 1:1:1 muestreo aleatorio. Se realizaron pruebas de reacción en cadena de la polimerasa con transcriptasa inversa (RT-PCR) para confirmación de laboratorio de sospecha de infección por el nuevo coronavirus y evaluación sociodemográfica y clínica. Resultados: de los 87 pacientes aleatorizados, 62,1% (n=54) eran del sexo masculino, con una edad media de 35,1 años, tenían pareja (53,9%), bajos ingresos (50,6%), eutróficos (40,7%) y sin comorbilidades de salud (78,2%). No hubo diferencia entre la mediana de tiempo hasta la resolución de los síntomas, que fue de 21 días (RIC, 8-30) en el grupo de atazanavir, 30 días (RIC, 5- 90) en el grupo de ivermectina en comparación con 14 días (RIC, 9 - 21) en el grupo control. En el día 180, hubo una resolución de los síntomas del 100 % en el grupo de placebo, del 93,9 % en el grupo de atazanavir y del 95 % en el grupo de ivermectina. La mediana de duración de la enfermedad fue de 8 días en todos los brazos del estudio. Conclusión: El tratamiento con atazanavir (6 días) e ivermectina (3 días) no redujo el tiempo de resolución de los síntomas ni la duración de la enfermedad entre los pacientes ambulatorios con COVID-19 leve en comparación con el grupo placebo. Los resultados no respaldan el uso de ivermectina y atazanavir para el tratamiento de la COVID-19 de leve a moderada.

Salmonella isolated from chicken carcasses from a slaughterhouse in the state of Mato Grosso, Brazil: antibiotic resistance profile, serotyping, and characterization by repetitive sequence-based PCR system.

Salmonella is one of the major causative agents of foodborne infections. Salmonellosis becomes more dangerous when strains resistant to several antibiotics are found in food, especially in chicken, one of the primary transmission vehicles of this pathogen for humans. The present study aimed to estimate the occurrence of Salmonella in chicken carcasses from the state of Mato Grosso, Brazil, as well as determine the antibiotic resistance profile and genotypic characteristic of multi-drug resistant (MDR) isolates. During a 15-month period, from 01/2014 to 05/2015, 850 samples of chilled fresh chicken carcasses were sampled from a slaughterhouse and submitted to Salmonella determinations according to the ISO-6579/2002 method, serotyping and multiplex PCR. The disc diffusion test was applied for 17 antibiotics, according to CLSI (2014). Five isolates were genotyped by repetitive sequence-based PCR using the semi-automated DiversiLab (bioMérieux®) system. The occurrence of Salmonella in chicken carcasses was of 3.7% (31/850), with only 4 strains (12.9%) presenting as MDR, and 6 strains (19.35%) displaying ESBL. The predominant serovars were Salmonella Infantis (35.4%, 11/31), and S. Abony (25.8%, 8/31), followed by serovars S. Agona (12.9%, 4/31), S. Schwarzengrund (9.7%, 3/31), S. Anatum and Salmonella enterica O:4,5 (6.5%, 2/31), and only one Salmonella enterica O:6,7 strain (3.2%, 1/31). All isolates were resistant to one to 5 classes of antibiotics in decreasing order: folate pathway inhibitors, ß-lactams (cephalosporins, penicillin, monobactams), tetracyclines, chloramphenicol, and gentamicin. However, strains sensitive to florfenicol, streptomycin, nalidixic acid, ciprofloxacin, enrofloxacin, and nitrofurantoin were also found in this study. Genotyping revealed 98 to 99% homology between 3 Salmonella strains, which displayed high phenotypic resistance similarity to ß-lactams and folate pathway inhibitors. Detection of MDR non-typhoid Salmonella in chicken slaughterhouses with quality assurance systems such as Hazard Analysis and Critical Points and Implemented Good Manufacturing Practices is a concern, reinforcing the need for constant monitoring of these pathogens, with the purpose of safeguarding the safety of their products.