Marciane Magnani

Molecular identification of Aspergillus spp. isolated from coffee beans

Some species belonging to the genus Aspergillus are potential producers of ochratoxin A (OA), a mycotoxin with nephrotoxic, immunosuppressive, teratogenic and carcinogenic effects. The aim of the present study was to identify the species of Aspergillus that contaminate the inside of coffee beans collected in the stage of maturation and drying, from 16 producing areas located in the northern region of the State of Parana, in the South of Brazil. A total of 108 isolates of Aspergillus spp. was identified at the species level, by sequencing the internal transcribed spacer (ITS1-5.8S-ITS2) of ribosomal DNA (rDNA). The results revealed the presence of potentially ochratoxigenic species in 82% of the geographic regions studied, among which Aspergillus niger was the species most frequently detected, followed by A. ochraceus and A. carbonarius. The presence of A. carbonarius in immature coffee fruits harvested from trees is reported for the first time.

Ciprofloxacin susceptibility reduction of Salmonella strains isolated from outbreaks

The antimicrobial susceptibility of 212 Salmonella strains isolated from patients and foods was evaluated and 45% were found to be resistant to nalidixic acid. Nalidixic acid resistant strains showed a higher minimal inhibitory concentration for ciprofloxacin than sensitive strains. During the study an increase of strains with reduced susceptibility to ciprofloxacin was also observed.

Protective effect of carboxymethyl-glucan (CM-G) against DNA damage in patients with advanced prostate cancer

Carboxymethyl-glucan (CM-G) is a soluble derivative from Saccharomyces cerevisiae (1 → 3)(1 → 6)-β-D-glucan. The protective efficiency of CM-G against DNA damage in cells from patients with advanced prostate cancer (PCa), and undergoing Androgen Deprivation Therapy (ADT), was evaluated. DNA damage scores were obtained by the comet assay, both before and after treatment with CM-G. The reduction in DNA damage, ranging from 18% to 87%, with an average of 59%, was not related to the increased number of leukocytes in peripheral blood. The results demonstrate for the first time the protective effect of CM-G against DNA damage in patients with advanced PCa. Among smokers, three presented the highest reduction in DNA damage after treatment with CM-G. There was no observable relationship between DNA damage scores before and after treatment, and age, alcoholism and radiotherapy.

Molecular characterization and resistance profile of Salmonella Enteritidis PT4 and PT9 strains isolated in Brazil

A total of 41 Salmonella Enteritidis strains, including phago-types (PTs) PT4 and PT9, were characterized by antimicrobial resistance profiles and PFGE. Of these strains, 34 were isolated from patients and foods, and 7 were of poultry origin. All strains were susceptible to ampicillin, chloramphenicol, cefotaxime, ciprofloxacin and trimethoprim/sulfamethoxazole, and 41.5 % (n = 17) were resistant to nalidixic acid. PFGE analysis using XbaI and SpeI restriction enzymes resulted in X1S1 as the prevalent pattern, which was present in 48.8 % (n = 20) of epidemic strains and in one strain isolated from discarded hatching eggs. Distinct patterns were found for the other strains isolated from poultry (X3S1, X8S8, X11S12, X11S13, X16S1 and X13S15). The S. Enteritidis PT9 strains associated with outbreaks of salmonellosis were highly similar (≥0.90), suggesting clonality. The PFGE genotypes were related to the PTs, and it was possible to differentiate strains isolated from patients with salmonellosis from other strains of non-epidemic origin. The PFGE results suggested that the S. Enteritidis strains of poultry origin were a possible source of human salmonellosis during the study period.

Expression of the marA, soxS, acrB and ramA genes related to the AcrAB/TolC efflux pump in Salmonella entérica strains with and without quinolone resistance-determining regions gyrA gene mutations

Several studies have been conducted in recent years to elucidate the structure, function and significance of AcrB, MarA, SoxS and RamA in Salmonella enterica. In this study, the relative quantification of acrB, soxS, marA and ramA genes expression was evaluated in 14 strains of S. enterica, with or without accompanying mutations in the quinolone resistance-determining regions of the gyrA gene, that were exposed to ciprofloxacin during the exponential growth phase. The presence of ciprofloxacin during the log phase of bacterial growth activated the genes marA, soxS, ramA and acrB in all S. enterica strains analyzed in this study. The highest expression levels for acrB were observed in strains with gyrA mutation, and marA showed the highest expression in the strains without mutation. Considering only the strains with ciprofloxacin minimum inhibitory concentration values<0.125 μg/mL (sensitive to ciprofloxacin), the most expressed gene in the strains both with and without mutations was acrB. In the strains with ciprofloxacin minimum inhibitory concentration values ≥ 0.125 μg/mL (low susceptibility), with and without mutations in gyrA, the most expressed gene was marA. In this study, we observed that strains resistant to nalidixic acid may express genes associated with the efflux pump and the expression of the AcrAB-TolC pump genes seems to occur independently of mutations in gyrA.

Analysis of peripheral T cells and the CC chemokine receptor (CCR5) delta32 polymorphism in prostate cancer patients treated with carboxymethyl-glucan (CM-G)

β-Glucan, derived from Saccharomyces cerevisiae, is a biological response modifier which affects the innate and adaptive immune responses. The CCR5 chemokine receptor is crucial for immune cell responses. In this study, the effects of the carboxymethylated form of β-glucan (CM-G) on the lymphocyte population of CCR5 genotype patients with prostate cancer (PCa), undergoing androgen deprivation therapy (ADT) was assessed. The CCR5 genotype and lymphocyte population was investigated by cytometry flow in 30 Brazilian patients with advanced PCa who were treated with CM-G for 28 days. The analysis of the CCR5 chemokine receptor revealed that the wild-type genotype Wt/Wt was present in 80% of patients, while the heterozygotic genotype Wt/delta32 was present in 20% of patients. After CM-G administration, a significant increase in CD3+, CD4+ and CD8+ T lymphocytes was observed in patients who displayed the wild-type genotype for the CCR5 chemokine receptor. No association was found between patients age or length of ADT and increase in T lymphocyte cells. The results demonstrated the ability of CM-G to stimulate CD4+ and CD8+ T cells in the peripheral blood of patients carrying a wild-type CCR5 genotype, suggesting an interaction between immunomodulation by CM-G and the CCR5 receptor.

Commercially laid eggs vs. discarded hatching eggs: contamination by Salmonella spp

Salmonella enterica is frequently associated with outbreaks of human salmonellosis, and products of avian origin, such as eggs and chicken meat, are the main vehicles of its transmission. The present study describes the occurrence of different serovars of Salmonella enterica and phagotypes of S. enterica serovar Enteritidis in eggs destined for human consumption. Four thousand eggs obtained from commercial egg laying farms and one thousand discarded hatching eggs from broiler farms, which were acquired at farmers’ markets and informal shops, were analyzed. Salmonella spp. was isolated from 52.0% of the discarded hatching eggs, in which the predominant serovar was Enteritidis (84.6%), and the predominant Salmonella Enteritidis phagotype (PT) was PT7 (26.9%). Salmonella spp. was not isolated from eggs obtained from commercial egg laying farms. The antimicrobial resistance profile showed that 23.1% (n = 6) of the SE strains were resistant to nalidixic acid. The results suggest that the consumption of discarded hatching eggs represents an important source of Salmonella transmission to humans.

Detection of quinolone-resistance mutations in salmonella spp. Strains of epidemic and poultry origin.

Mutations into codons Aspartate-87 (62%) and Serine-83 (38%) in QRDR of gyrA were identified in 105 Salmonella strains resistant to nalidixic acid (94 epidemic and 11 of poultry origin). The results show a high incidence of mutations associated to quinolone resistance but suggest association with others mechanisms of resistance.