Alessandra Barbosa Ferreira-Machado

Aerobic exercise and not a diet supplemented with jussara açaí ( Euterpe edulis Martius) alters hepatic oxidative and inflammatory biomarkers in ApoE-deficient mice

The pulp of jussara açaí (Euterpe edulis Martius) fruit is rich in anthocyanins that exert antioxidant and anti-inflammatory effects similar to those exerted by aerobic exercise. In the present study, we investigated the effects of jussara açaí fruit pulp consumption, either alone or in combination with aerobic exercise, on the hepatic oxidative and inflammatory status of ApoE-deficient (ApoE - / - ) mice. Male mice were divided into four groups (control (C), control plus açaí, exercise plus açaí (EXA) and exercise (EX)) and fed the AIN-93M diet or the AIN-93M diet formulated to contain 2 % freeze-dried açaí pulp. Mice in the EX and EXA groups were subjected to a progressive running programme (5 d/week, 60 min/d, 16 m/min) for 12 weeks. Mice that were made to exercise exhibited reduced (40·85 %; P< 0·05) hepatic superoxide dismutase activity when compared with the C mice, independent of the açaí diet. Mice in the EX group exhibited a lower (42 %; P< 0·05) mRNA expression of monocyte chemotactic protein-1 in the liver compared with the C mice. Mice in the EXA and EX groups had lower percentages of hepatic lipid droplets (70 % and 56 %, respectively; P< 0·05) when compared with the C mice. Mice in the EX group had smaller (58 %; P< 0·05) area of lesions in the aorta when compared with the C mice. Serum lipid profile was not affected (P>0·05). In conclusion, aerobic exercise training rather than açaí fruit pulp consumption or a combination of both enhances the hepatic oxidative and inflammatory status of ApoE - / - mice.

Prevalence, Antimicrobial Resistance, and Virulence Characteristics of mecA‐Encoding Coagulase‐Negative Staphylococci Isolated from Soft Cheese in Brazil

Coagulase-negative staphylococci (CoNS), which are generally neglected as foodborne bacteria, are emerging as significant opportunistic pathogens that may be highly resistant to available antimicrobial drugs. In this study, antimicrobial susceptibility patterns, mecA gene occurrence, and virulence-associated characteristics were evaluated in CoNS isolated from soft cheese in Brazil. A total of 227 bacterial isolates were recovered from 35 cheese samples belonging to 5 batches with 7 different trademarks. The CoNS counts ranged from 10(6) to 10(7) CFU/g. High antimicrobial resistance percentages were observed for oxacillin (76.2%), penicillin (78.5%), erythromycin (67.8%), gentamicin (47.2%), clindamycin (35.7%), rifampicin (26.8%), azithromycin (14.7%), tetracycline (14.7%), levofloxacin (14.2%), and sulfamethoxazole-trimethoprim (11.9%). A low antimicrobial resistance percentage was observed for chloramphenicol (2.3%), and all of the tested bacteria were susceptible to vancomycin and linezolid. In total, a multiple antibiotic resistance (MAR) index of >0.2 was observed for 80.6% of the isolated CoNS. However, the MAR index ranged from 50% to 92.6% when only bacterial cheese isolates belonging to the same trademark were considered. Regarding to the prevalence of CoNS carrying mecA gene, 81.5% of the isolated strains were mecA(+) , and 76.2% of these were phenotypically resistant to oxacillin. Three isolates carried the enterotoxin A gene (sea), 29.5% produced biofilm in a laboratory test, and α- or ß-hemolysis were observed for 3% and 5.2%, respectively. This study highlights the extent of the antimicrobial resistance phenomenon in neglected foodborne microorganisms and the potential public health risks that are related to the consumption of CoNS-contaminated soft cheese.

Exploratory Investigation of Bacteroides fragilis Transcriptional Response during In vitro Exposure to Subinhibitory Concentration of Metronidazole

Bacteroides fragilis, member from commensal gut microbiota, is an important pathogen associated to endogenous infections and metronidazole remains a valuable antibiotic for the treatment of these infections, although bacterial resistance is widely reported. Considering the need of a better understanding on the global mechanisms by which B. fragilis survive upon metronidazole exposure, we performed a RNA-seq transcriptomic approach with validation of gene expression results by qPCR. Bacteria strains were selected after in vitro subcultures with subinhibitory concentration (SIC) of the drug. From a wild type B. fragilis ATCC 43859 four derivative strains were selected: first and fourth subcultures under metronidazole exposure and first and fourth subcultures after drug removal. According to global gene expression analysis, 2,146 protein coding genes were identified, of which a total of 1,618 (77%) were assigned to a Gene Ontology term (GO), indicating that most known cellular functions were taken. Among these 2,146 protein coding genes, 377 were shared among all strains, suggesting that they are critical for B. fragilis survival. In order to identify distinct expression patterns, we also performed a K-means clustering analysis set to 15 groups. This analysis allowed us to detect the major activated or repressed genes encoding for enzymes which act in several metabolic pathways involved in metronidazole response such as drug activation, defense mechanisms against superoxide ions, high expression level of multidrug efflux pumps, and DNA repair. The strains collected after metronidazole removal were functionally more similar to those cultured under drug pressure, reinforcing that drug-exposure lead to drastic persistent changes in the B. fragilis gene expression patterns. These results may help to elucidate B. fragilis response during metronidazole exposure, mainly at SIC, contributing with information about bacterial survival strategies under stress conditions in their environment.

Potential spread of multidrug-resistant coagulase-negative staphylococci through healthcare waste

INTRODUCTION Healthcare waste (HCW) might potentially harbor infective viable microorganisms in sanitary landfills. We investigated the antimicrobial susceptibility patterns and the occurrence of the mecA gene in coagulase-negative Staphylococcus strains (CoNS) recovered from the leachate of the HCW in an untreated sanitary landfill. METHODOLOGY Bacterial identification was performed by physiological and molecular approaches, and minimum inhibitory concentrations (MICs) of antimicrobial drugs were determined by the agar dilution method according to CLSI guidelines. All oxacillin-resistant bacteria were screened for the mecA gene. RESULTS Out of 73 CoNS, seven different species were identified by 16S rDNA sequencing: Staphylococcus felis (64.4%; n = 47), Staphylococcus sciuri (26.0%; n = 19), Staphylococcus epidermidis (2.7%; n = 2), Staphylococcus warneri (2.7%; n = 2), Staphylococcus lentus (1.4%; n = 1), Staphylococcus saprophyticus (1.4%; n = 1), and Staphylococcus haemolyticus (1.4%; n = 1). Penicillin was the least effective antimicrobial (60.3% of resistance; n = 44) followed by erythromycin (39.8%; n = 29), azithromycin (28.8%; n = 21), and oxacillin (16.5%; n = 12). The most effective drug was vancomycin, for which no resistance was observed, followed by gentamicin and levofloxacin, for which only intermediate resistance was observed (22%, n = 16 and 1.4%, n = 1, respectively). Among the oxacillin-resistant strains, the mecA gene was detected in two isolates. CONCLUSIONS Considering the high antimicrobial resistance observed, our results raise concerns about the survival of putative bacterial pathogens carrying important resistance markers in HCW and their environmental spread through untreated residues discharged in sanitary landfills.

Methicillin-resistant Staphylococcus aureus isolated from an intensive care unit in Minas Gerais, Brazil, over a six-year period

To characterize methicillin-resistant Staphylococcus aureus isolates from an intensive care unit of a tertiary-care teaching hospital, between 2005 and 2010. A total of 45 isolates were recovered from patients admitted to the intensive care unit in the study period. Resistance rates higher than 80% were found for clindamycin (100%), erythromycin (100%), levofloxacin (100%), azithromycin (97.7%), rifampin (88.8%), and gentamycin (86.6%). The SCCmec typing revealed that the isolates harbored the types III (66.7%), II (17.8%), IV (4.4%), and I (2.2%). Four (8.9%) isolates carried non-typeable cassettes. Most (66.7%) of the isolates were related to the Brazilian endemic clone from CC8/SCCmec III, which was prevalent (89.3%) between 2005 and 2007, while the USA100/CC5/SCCmec II lineage emerged in 2007 and was more frequent in the last few years. The study showed high rates of antimicrobial resistance among methicillin-resistant S. aureus isolates and the replacement of Brazilian clone, a well-established hospital lineage, by the USA100 in the late 2000s, at the intensive care unit under study.

Epidemiology and antimicrobial susceptibility trends of methicillin-resistant Staphylococcus aureus in a tertiary hospital

Introduction: Staphylococcus aureus is a major cause of health care associated infections worldwide. Objective: The aim of this work was to evaluate epidemiological characteristics and antimicrobial susceptibility of Methicillin-resistant S . aureus (MRSA) strains isolates from infections in a Brazilian tertiary hospital. Methods: Clinical and epidemiological data of the patients were collected. Bacterial strains were isolated and identified using the classical identification tests. Antimicrobial susceptibility assays were performed using the disc-diffusion method. Findings: A total of 590 samples of S. aureus were isolated from patients and 42.5% were characterized as MRSA. Considering the clinical specimens, most of samples were isolated from blood and tracheal secretion, catheter tip, surgical site swabs, wound secretion, exudates and urine. Overall, a high frequency of resistance was observed against ciprofloxacin, clindamycin, erythromycin, amikacin, gentamicin, trimethoprim-sulfamethoxazole, tetracycline and chloramphenicol. Association between death and multidrug-resistance in elderly patients, and death and occurrence of bacteremia by multidrug-resistant MRSA was observed. Conclusions: Our data are highly relevant for surveillance systems and to map on a wider scale the dynamics of circulation of MRSA and raise discussions on containment strategies and rational use of empiric chemotherapy.

Antimicrobial-Resistance Genetic Markers in Potentially Pathogenic Gram Positive Cocci Isolated from Brazilian Soft Cheese: Antimicrobial-resistance genetic markers…

Although most Brazilian dairy products meet high technological standards, there are quality issues regarding milk production, which may reduce the final product quality. Several microbial species may contaminate milk during manufacture and handling. If antimicrobial usage remains uncontrolled in dairy cattle, the horizontal transfer of antimicrobial resistance genes in foodstuffs may be of particular concern for both food producers and dairy industry. This study focused on the evaluation of putative Gram positive cocci in Minas cheese and of antimicrobial and biocide resistance genes among the isolated bacteria. Representative samples of 7 different industrially trademarked Minas cheeses (n = 35) were processed for selective culture and isolation of Gram positive cocci. All isolated bacteria were identified by DNA sequencing of the 16S rRNA gene. Antimicrobial resistance genes were screened by PCR. Overall, 208 strains were isolated and identified as follows: Enterococcus faecalis (47.6%), Macrococcus caseolyticus (18.3%), Enterococcus faecium (11.5%), Enterococcus caseliflavus (7.7%), Staphylococcus haemolyticus (7.2%), Staphylococcus aureus (4.3%), Staphylococcus epidermidis (2.9%), and Enterococcus hirae (0.5%). The genetic markers mecA (78.0%) and smr (71.4%) were the most prevalent, but others were also detected, such as blaZ (65.2%), msrA (60.9%), msrB (46.6%), linA (54.7%), and aacA-aphD (47.6%). The occurrence of opportunist pathogenic bacteria harboring antimicrobial resistance markers in the cheese samples are of special concern, since these bacteria are not considered harmful contaminating agents according to the Brazilian sanitary regulations. However, they are potentially pathogenic bacteria and the cheese may be considered a reservoir for antimicrobial resistance genes available for horizontal transfer through the food chain, manufacturing personnel and consumers.

Antimicrobial susceptibility and vaginolysin in Gardnerella vaginalis from healthy and bacterial vaginosis diagnosed women

INTRODUCTION Bacterial vaginosis (BV) is a syndrome related to Gardnerella vaginalis and is characterized by an imbalance in the vaginal microbiota. This work focused on the evaluation of antimicrobial susceptibility patterns and the occurrence of the vaginolysin (vly) gene in G. vaginalis isolated from BV and non-BV patients. METHODOLOGY The vaginal secretions were collected randomly and processed for G. vaginalis isolation. The isolates were presumptively identified by β-hemolysis and oxidase and catalase tests. Polymerase chain reaction (PCR) was performed to confirm bacterial identity and to detect the vly gene. Antimicrobial susceptibility patterns were determined. RESULTS Of 89 patients, G. vaginalis was isolated from 42 (37 BV and 5 non-BV), and 204 isolates were selected (179 from BV and 25 non-BV). The vly gene was detected in all G. vaginalis isolated from non-BV women and in 98.3% of the bacteria from BV patients. High resistance was observed for ampicillin (54.4%), metronidazole (59.8%), tinidazole (60.3%) and secnidazole (71.6%). CONCLUSIONS Further studies are needed to better address the role of G. vaginalis and the vly gene in BV pathogenesis.