Detection and Quantification of Campylobacter in Poultry Slaughterhouses Using Conventional Microbiological Technique, Most Probable Number, and Real-Time PCR.

Campylobacteriosis is one of the most common bacteria causing human gastroenteritis. Poultry is a major reservoir of Campylobacter spp. as well as the main source of transmission. Due to the increased occurrence of campylobacteriosis, poultry slaughterhouses are under pressure to deliver carcasses with low contamination. However, a few studies have been carried out to evaluate Campylobacter contamination of broiler carcasses in Brazilian slaughter lines. Therefore, in this study, we aimed at detecting and quantifying the thermotolerant Campylobacter spp. at different stages of the poultry slaughtering process. The samples were collected from 12 points in three slaughterhouses in southern Brazil, at an interval of 12 months, and were tested for Campylobacter spp. by conventional microbiological technique, the most probable number, and real-time PCR. A total of 432 samples were analyzed. The majority of strains belonged to Campylobacter jejuni (92%), and the flock positivity among the three techniques was similar in most cases. Campylobacter was detected in all slaughtering stages. Although contamination has remained similar (p > 0.05) throughout almost all the slaughter process, evisceration seemed to be an important source of contamination. Our results reinforce the idea that the final carcass quality after the slaughtering process is directly influenced by the level of contamination of the broiler flocks on arrival at the processing plant.

Identification of pathogenic genes in Campylobacter jejuni isolated from broiler carcasses and broiler slaughterhouses.

Campylobacter jejuni is one of the most common causes of foodborne diseases worldwide. There are few reports on Campylobacter strains isolated from Latin-American countries. Here, 140 C. jejuni strains isolated from cloacal and transport boxes swabs, water from chiller tanks, and broiler carcasses of five poultry companies in Southern Brazil were identified using phenotypic and genotypic methods. Polymerase chain reaction (PCR) was used to analyze eight C. jejuni virulence markers: flaA, cadF, and invasion-associated (iam) genes, cdtABC operon (associated with the cytolethal distending toxin), and plasmidial virB11 and wlaN genes were present in 78.5%, 77.8%, 0%, 74.2%, 22.1%, and 10.7% of samples, respectively. There were 25 different virulence profiles: 1 (cdtA, cdtB, cdtC, flaA, and cadF), 2 (cdtA, cdtB, cdtC, flaA, cadF, and virB11), and 3 (cdtA, cdtB, cdtC, flaA, cadF, and wlaN) were the most common (> 60% of strains). We provide insight into factors related to the occurrence of this pathogen and their epidemiology.

Fluoroquinolone resistance in Campylobacter jejuni and Campylobacter coli from poultry and human samples assessed by PCR-restriction fragment length polymorphism assay.

The objective of this study was to determine fluoroquinolone resistance in Campylobacter spp from poultry and human isolates. Forty-one Campylobacter jejuni isolates (30 of poultry origin and 11 of human origin) and 11 Campylobacter coli isolates (10 of human origin and 1 of poultry origin) were examined for ciprofloxacin, norfloxacin, and nalidixic acid resistance using the minimal inhibitory concentration (MIC) method. Thereafter, the isolates were analyzed by PCR-Restriction Fragment Length Polymorphism (RFLP) assay for detection of Thr-86 mutation. Finally, DNA sequencing was performed for confirmation of gyrA gene mutation. A complete correlation was observed between MICs, PCR-RFLP assay, and sequencing. The results revealed high quinolone resistance rates for C. jejuni (100%) and C. coli (100%) isolates obtained from poultry and moderate resistance for C. jejuni (9.1%) and C. coli (40%) samples of human origin. A mutation in codon 86 of the gyrA gene with a Thr-to-Ile substitution is reported to be the main cause of high resistance to quinolones. This mutation can be analyzed by PCR-RFLP assay, which has been proven to be a simple and fast method for the detection of fluoroquinolone resistance in Campylobacter spp.

Effectiveness of high-power diode laser associated to chemical auxiliary substance on decontamination of root canal system infected with Enterococcus faecalis ? an in vitro study

Objective: to evaluate the additional antibacterial ac-tion of high-power diode laser after the use of 2.5% sodium hypochlorite and 2% chlorhexidine gel in root canals infected with E.faecalis. Materials and method: 120 human teeth with single canal were inoculated with E.faecalis for 14 days and randomly divided into six groups (n=20), according to the chemical auxiliary substance used in the chemo-mechanical preparation and the use of high-power diode laser: G1(NaOCl) ? root canal preparation with 2.5% sodium hypo-chlorite; G2(CHX) ? root canal preparation with 2% chlorhexidine gel; G3(NaOCl+DL) - root canal pre-paration with 2.5% sodium hypochlorite+diode la-ser; G4(CHX+DL) - root canal preparation with 2% chlorhexidine gel+diode laser; G5(NaCl+DL) - root canal preparation with 0.9% saline solution+diode la-ser; G6(no treatment) ? no treatment was performed. Microbiological test (CFUs counting) was performed to evaluate the effectiveness of proposed treatments. Data were subjected to One-way ANOVA followed by post-hoc Tukey test (?=0.05). Results: G3(NaOCl+DL) had reduction of 99.42% of E.faecalis, followed by G4(CHX+DL) ? 93.48%; G1(NaOCl) ? 89.82%; G2(CHX) ? 81.86%; G5(NaCl+DL) ? 65.40%; and G6(no treatment) ? no reduction. There was significant statistical difference in CFUs of all groups in relation to G6(no treatment) (p<0.05). G1(NaOCl), G2(CHX), G3(NaOCl+DL) and G4(CHX+DL) were statistically superior to G5(NaCl+DL) (p<0,05). Conclusion: High--power diode laser, when associated with 2.5% NaOCl or 2% CHX, improves the antimicrobial effect of these substances in the root canals infected with E. faecalis.

Análise comparativa entre microbiologia convencional, ELISA e PCR para detecção de Salmonella enteritidis, S. typhimurium, S. gallinarum e S. pullorum em carne de frango contaminada artificialmente

O presente trabalho teve como objetivo realizar uma análise comparativa das técnicas de Reação em Cadeia pela Polimerase(PCR) e Ensaio Imunoenzimático (ELISA SALVIA®) com o método microbiológico convencional para detecção e SalmonellaEnteritidis (SE), S. typhimurium (ST), S. gallinarum (SG) e S. pullorum (SP) em carne de frango. As amostras foram contaminadasartificialmente com diluições de 10-7, 10-8 e 10-9 para SE e ST e de 10-4, 10-5 e 10-6 para SG e SP, com cinco repetições decada diluição, totalizando 300 análises. Os testes foram realizados em cinco diferentes laboratórios para a validação dastécnicas. Na avaliação geral dos dados obtidos, a microbiologia convencional obteve 56,67% (170/300) de recuperação dasamostras contaminadas artificialmente, enquanto as técnicas de ELISA e PCR representaram 71% (213/300) e 75% (225/300), respectivamente. A análise dos resultados de detecção de Salmonella através dos testes ELISA e PCR, em relação aomicrobiológico convencional, apresentaram diferença estatística (p=0,0001, teste de MacNemar). Não houve diferença significativaentre os resultados da PCR e do ELISA. Os resultados alcançados demonstraram que, comparado ao microbiológicoconvencional, tanto o ELISA quanto a PCR foram eficazes para detecção dos sorovares de Salmonella nas amostras de carnede frango avaliadas.