ABSTRACT Antimicrobial resistance is a serious public health problem and Salmonella spp. is highly resistant to antimicrobial agents. Biofilms are important in the food industry due to their formation on products, utensils, and surfaces and the difficulty in their removal. The objective of this study was to assess extended spectrum beta-lactamase (ESBL) production, antimicrobial resistance, and biofilm production of Salmonella isolated from poultry slaughterhouses. Antimicrobial susceptibility was assessed by the disk diffusion assay and ESBL by double diffusion disk assay using the beta-lactamase inhibitor (amoxicillin+clavulanate). The antimicrobials tested were: ampicillin, amoxicillin+clavulanate, aztreonam, ceftazidime, cefotaxime, chloramphenicol, gentamicin, enrofloxacin, sulfonamide, and tetracycline. Serovars Infantis, Panamá, and Tennessee were found to produce ESBL. All serovars were sensitive to tetracycline, and S. Brandenburg was sensitive to all drugs tested. Serovars Panamá, Anatum, Infantis, and Schwarzengrund were moderate biofilm producers at 3 ºC and 9 ºC±1 ºC, respectively, showing possible adaptation of these serovars to these temperatures. Antimicrobials should be used with caution because of the levels of resistance observed and because of ESBL production, and hygiene and sanitary measures should be enhanced to minimize the adhesion of biofilm-forming Salmonella serovars at refrigeration temperatures.

ABSTRACT Broiler carcasses presenting cachexia, as determined by the federal inspection agency, were submitted to microbiological, physicochemical, and histological analyses. Over a 2-month period, 278 carcasses from straight-run flocks of 43- to 48-d-old Cobb broilers from two different farms were condemned due to cachexia and subjected to gross examination in the final inspection sector. Out of the 278 carcasses, 131 did not present any gross signs of infection, and were submitted to microbiological analyses (n=83), physicochemical analyses (n=28), and viscera and muscle samples of 20 carcasses were evaluated by histology. The microbiological results of cachectic carcasses complied with the current legislation on the consumption of fresh poultry meat. Lower lipid and higher protein, moisture, and volatile matter contents, and higher pH (p<0.05) were determined in the cachectic than in the control carcasses from a same flock, but no ash content differences. All carcasses were negative for hydrogen sulfide. The histological analysis showed that65% of the cachectic carcasses did not have any muscle injury, 20% showed mild hyalinization and 15% moderate proliferation of fibrous connective tissue. The findings of this study indicate the importance of further technical and scientific studies on the utilization of cachectic broiler carcasses for the manufacture of edible products, rather than whole carcasses rendering, thereby preventing the resulting economic losses.

ABSTRACT There are several causes of carcass condemnation in poultry processing plants, including dorsal cranial myopathy (DCM), in which the anterior latissimus dorsi (ALD) muscle is affected. DCM etiology has not been elucidated yet, but this lesion impairs the visual quality of carcasses and causes economic losses due to downgrading and condemnation. The effects of this lesion on the systemic health of broilers are still unknown. In this context, the objective of this study was to evaluate muscle injury and systemic health indicators in broilers presenting or not DCM. The following parameters were evaluated: complete blood count (CBC), total protein, albumin, globulin, cholesterol, lactate, and glucose serum levels, aspartate aminotransferase (AST) and creatine kinase (CK) serum activities, and breast muscle pH. Blood samples were collected from 800 42-day-old broilers before feed withdrawal and transportation. In the processing plant, 28 carcasses presented DCM during inspection, and 28 carcasses with no DCM were used as controls. Blood biochemical parameters were not significantly different between broilers with DCM and the controls, except for AST and CK, which activities were higher in the DCM group than in the control group, suggesting that the DCM does not affect the systemic health of the broilers.

ABSTRACT The routine use of antimicrobials in animal production for the treatment of infections, disease prevention, or as growth promoters is a predisposing factor for the development and dissemination of antimicrobial resistance. In food industries, sanitizers are used for the control of microbial colonization, and their efficacy depends on contact time and on the dilution of the products used. The present study assessed the effect of 12 antimicrobials and four commercial sanitizers on 18 Salmonella spp. strains isolated from poultry processing plants. None of the evaluated antimicrobials was 100% effective against the tested Salmonella spp. strains; however, 94% of the isolates were susceptible to ciprofloxacin, 77% to amoxicillin + clavulanic acid and to ampicillin, and 72% to enrofloxacin, whereas 100% of the isolates were resistant to penicillin G, 16% to tetracycline, and 11% to sulfonamide. The tested Salmonella spp. strains were 100% inhibited by peracetic acid after five minutes of contact, 0.5% by quaternary ammonium after 15 minutes, and 85.7% by chlorhexidine after 15 minutes. The results indicate the importance of testing of efficacy of antimicrobials used in animal production and in public health to monitor their action and the development of resistance.

Salmonella is traditionally identified by conventional microbiological tests, but the enumeration of this bacterium is not used on a routine basis. Methods such as the most probable number (MPN), which utilize an array of multiple tubes, are time-consuming and expensive, whereas miniaturized most probable number (mMPN) methods, which use microplates, can be adapted for the enumeration of bacteria, saving up time and materials. The aim of the present paper is to assess two mMPN methods for the enumeration of Salmonella sp in artificially-contaminated chicken meat samples. Microplates containing 24 wells (method A) and 96 wells (method B), both with peptone water as pre-enrichment medium and modified semi-solid Rappaport-Vassiliadis (MSRV) as selective enrichment medium, were used. The meat matrix consisted of 25g of autoclaved ground chicken breast contaminated with dilutions of up to 10(6) of Salmonella Typhimurium (ST) and Escherichia coli (EC). In method A, the dilution 10-5 of Salmonella Typhimurium corresponded to >57 MPN/mL and the dilution 10-6 was equal to 30 MPN/mL. There was a correlation between the counts used for the artificial contamination of the samples and those recovered by mMPN, indicating that the method A was sensitive for the enumeration of different levels of contamination of the meat matrix. In method B, there was no correlation between the inoculated dilutions and the mMPN results.

Salmonellosis is an important disease with economic impact as it may affect animal performance and may result in foodborne disease in humans through the eggs and carcass contamination. Regarding the Salmonella control, it is possible to decrease its fecal excretion and the contamination of chicken carcasses by adding organic acids to the feed or drinking water at appropriate times. The aim of this study was to test a blend of organic acids and essential oils in broilers challenged with Salmonella Enteritidis (SE), and to verify the fecal excretion of Salmonella. Sixty broilers were placed in four groups. One group was the negative control. Another group was orally inoculated at 1 day-old with 10(5) CFU/mL of SE as a positive SE control. Two groups (T3 and T4) were orally inoculated at 1 day-old with 10(5) CFU/mL of SE and their feed was separately treated with 0.5 and 1% of organic acids and essential oils, respectively. To assess the fecal excretion of SE, cloacal swabs were collected from all birds at 2, 6, 13 and 20 days after inoculation. The T3 and T4 groups showed a reduction in fecal excretion of SE at 6 and 20 days after inoculation.

The threat to public health represented by Salmonella is at least partially a consequence of its ecology in poultry hosts. Good manufacturing practices in the processing plant can reduce the contamination of poultry products, and critical control point principles are essential throughout the chain production. One procedure adopted in critical points control to prevent and to reduce Salmonella in farms and poultry products is the use of disinfectants. This study aimed at evaluating disinfectant efficiency against Salmonella enteritidis samples isolated from broiler carcasses in Rio Grande do Sul State between 1995 and 1996. The tested disinfectants were: phenol 1:256, quaternary ammonium 1:2500, glutaraldehyde 1:200, and iodine 1:500, with contact times of 5, 10, 15, and 20 in an in vitro test. .Phenolic compounds showed better results, iodine and glutaraldehyde showed intermediary results, and quaternary ammonium presented efficiency at all contact times evaluated in the in vitro test.

Campylobacter was investigated in cecal droppings, feces, and cloacal swabs of 22 flocks of 3 to 5 week-old broilers. Risk factors and the likelihood of the presence of this agent in these flocks were determined. Management practices, such as cleaning and disinfection, feeding, drinkers, and litter treatments, were assessed. Results were evaluated using Odds Ratio (OR) test, and their significance was tested by Fisher's test (p<0.05). A Campylobacter prevalence of 81.8% was found in the broiler flocks (18/22), and within positive flocks, it varied between 85 and 100%. Campylobacter incidence among sample types was homogenous, being 81.8% in cecal droppings, 80.9% in feces, and 80.4% in cloacal swabs (230). Flocks fed by automatic feeding systems presented higher incidence of Campylobacter as compared to those fed by tube feeders. Litter was reused in 63.6% of the farm, and, despite the lack of statistical significance, there was higher likelihood of Campylobacter incidence when litter was reused. Foot bath was not used in 45.5% of the flocks, whereas the use of foot bath associated to deficient lime management increased the number of positive flocks, although with no statiscal significance. The evaluated parameters were not significantly associated with Campylobacter colonization in the assessed broiler flocks.

Dirt floors are used on most Brazilian poultry farms since the construction of concrete floors is very expensive. In vitro tests carried out to verify the effectiveness of disinfectants do not consider the adverse conditions found in poultry farms. Therefore, the present study aimed at evaluating the effect of six commercial disinfectants on the reduction of total and fecal coliforms on the dirt floor of breeder houses. The amount of disinfectant solution to be used per square meter was defined by counting total and fecal coliforms at different soil depths and by analyzing soil physical properties. Coliforms were detected at 0.5 cm, and one liter of disinfectant solution was sufficient for soil saturation at this depth. After that, the efficacy of six commercial products (caustic soda, hydrated lime, phenols 1 and 2, iodine, glutaraldehyde, and quaternary ammonium) in reducing the number of coliforms, after six hours of contact with the dirt floor, was assessed using the most probable number (MPN) method. Escherichia coli specimens isolated from the dirt floor were used to evaluate in vitro effectiveness of disinfectants. Products that yielded the best results in the MPN method were also effective in the in vitro tests. Among the tested disinfectants, hydrated lime was the most efficient, reducing the initial contamination by 2.9 log after six hours of contact with the dirt floor.