Maria Cláudia Dantas Porfírio Borges André

Microbiological quality of organic vegetables produced in soil treated with different types of manure and mineral fertilizer

An attempt was made to evaluate microbiological quality of horticultural crops grown organically. Three species of vegetables were used, lettuce (Lactuva sativa), radish (Raphanus sativus) and spinach (Tetragonia expansa), grown organically, in fertile soil. Six different treatments were applied: mineral fertilizer, chicken, cow, and pig manure, chicken litter and cow manure, in association with a liquid foliar biofertilizer. These crops were handled according to correct agronomic practices for growing crops organically for commercial purposes. Samples were examined for the Most Probable Number (MPN/g/mL) of total and fecal coliforms and to detect the presence of Escherichia coli and Salmonella spp. All analyzed samples were considered acceptable for consumption, as Salmonella spp. was not detected. However, 63.3%, 50.0%, and 23.3% of the samples of lettuce, radish and spinach, respectively, contained >102 total coliforms/g of product. None of the samples of spinach or radish presented >102 fecal coliforms/g, and only 6.6% of lettuce samples contained >102 fecal coliforms/g. The presence of E. coli was confirmed in one sample of spinach, cultivated with cow manure.

Caracterização fenotípica pelo antibiograma de cepas de Escherichia coli isoladas de manipuladores, de leite cru e de queijo "Minas Frescal" em um laticínio de Goiás, Brasil

The present work aimed to type E. coli strains obtained from handlers hands and noses, raw milk and Minas Frescal cheese produced by a dairy milk processing plant in Goias, Brazil in order to establish a contamination relationship between the sources of E. coli and cheese. Twenty-four samples were collected from raw milk and Minas Frescal cheese, 46 from hands and 46 from noses of handlers involved in the cheese manufacturing, between March/2004 and February/2005. All 69 E. coli strains isolated were submitted to the susceptibility test for six antimicrobials (ampicillin, cephalothin, ciprofloxacin, gentamicin, trimethopim-sulphamethoxazole and tetracycline. The strains were grouped in 17 different phenotypic susceptibility profiles (A-Q). The test allowed to establish correlation among a cheese strain (14Qb) and a handler (10M1) strain that presented the same susceptibility profile (E) suggesting a possible product contamination during the handling. In conclusion, the phenotypic susceptibility profiles determinated by the antibiogram method failed to establish a correlation between the strains obtained from the probable sources (handlers and milk) and the final products.

Qualidade microbiológica de leite humano obtido em banco de leite

OBJECTIVE The objectives of the present study were to determine the prevalence of potentially pathogenic microorganisms that indicate the hygienic and sanitary conditions of human milk samples collected at a Human Milk Bank. METHODS Three hundred and thirty eight (338) samples of human milk collected from a milk bank in a maternity in the municipality of Goiânia, in the state of Goias, Brazil were submitted to microbiological analysis. The latter were plated on McConkey agar according to the type of bacteria. Among the total number of samples collected, 194 consisted of raw milk and the remaining 144 were pasteurized milk. RESULTS The presence of Staphylococcus spp., Streptococcus spp., yeasts and molds, and Enterobacteriaceae was verified in the raw milk samples. Staphylococcus aureus were isolated in 10 (5.2%) samples, Staphylococcus epidermidis in 28 (14.4%) samples, Streptococcus spp. in three (1.6%) samples, yeasts and molds in 43 (22.2%) and Enterobacteriaceae in 49 (25.3%) samples. In a hundred and forty four (144) samples which underwent thermal treatment Staphylococcus aureus was detected in five (3.5%) samples, Staphylococcus epidermidis in 15 (10.4%), Staphylococcus lugdenensis in two (1.4%), Streptococcus spp. in four (2.8%), yeasts and molds in 37 (25.7%), and Enterobacteriaceae in nine (6.3%). CONCLUSIONS Analysis indicated a high degree of contamination in raw human milk, and as for the pasteurized milk, despite elimination of the great majority of potentially pathogenic microorganisms, the percentage of yeasts and molds was higher than in raw milk, demonstrating that a lower degree of initial contamination would be necessary for pasteurization to be an efficient means of microbiological control.

Non-typeable Streptococcus pneumoniae carriage isolates genetically similar to invasive and carriage isolates expressing capsular type 14 in Brazilian infants.

OBJECTIVES We have recently found a high prevalence of non-typeable pneumococcal isolates (NTPn) circulating in day-care centers in Central Brazil, besides serotype 14 isolates. We therefore examined the genetic relationship among NTPn and serotype 14 from carriage and invasive pneumococcal isolates obtained from children attending emergency rooms enrolled in a population-based surveillance. METHODS The isolates were characterized by Quellung reaction serotyping, PCR for the presence of pneumolysin and the loci for a capsule gene (cpsA) and the type 14 gene (cps14H) in all NTPn, and by multilocus sequence typing and pulsed field gel electrophoresis. RESULTS 87.2% of the isolates were clustered into nine clusters. The major cluster included 41 pneumococcal serotype 14 (28 carriage and 13 invasive isolates) and two NTPn related to the global pneumococcal clone Spain(9V)-3. Overall, 95.4% of the NTPn carriage strains were genetically related to carriage or invasive strains expressing serotype 14. A dominant NTPn lineage was found, that grouped 14 pneumococcal strains. Almost half of the multidrug-resistant isolates grouped into the NTPn cluster. CONCLUSION These findings provide baseline data to assess the impact of the pneumococcal vaccination on the molecular epidemiology of Streptococcus pneumoniae. Changes in frequency of NTPn isolates and also genetic changes should be carefully monitored post vaccination, to detect potential vaccine-escape or replacement disease by capsule switched strains, especially in areas where colonization with NTPn has been frequently observed.

Molecular epidemiology of coagulase-negative Staphylococcus carriage in neonates admitted to an intensive care unit in Brazil

BackgroundNasal colonization with coagulase-negative Staphylococcus (CoNS) has been described as a risk factor for subsequent systemic infection. In this study, we evaluated the genetic profile of CoNS isolates colonizing the nares of children admitted to a neonatal intensive care unit (NICU).MethodsWe assessed CoNS carriage at admittance and discharge among newborns admitted to a NICU from July 2007 through May 2008 in one of the major municipalities of Brazil. Isolates were screened on mannitol salt agar and tryptic soy broth and tested for susceptibility to antimicrobials using the disc diffusion method. Polymerase chain reaction (PCR) was used to determine the species, the presence of the mecA gene, and to perform SCCmec typing. S. epidermidis and S. haemolyticus isolated from the same child at both admission and discharge were characterized by PFGE.ResultsAmong 429 neonates admitted to the NICU, 392 (91.4%) had nasal swabs collected at both admission and discharge. The incidence of CoNS during the hospitalization period was 55.9% (95% confidence interval [CI]: 50.9-60.7). The most frequently isolated species were S. haemolyticus (38.3%) and S.epidermidis (38.0%). Multidrug resistance (MDR) was detected in 2.2% and 29.9% of the CoNS isolates, respectively at admittance and discharge (p = 0.053). The mecA gene was more prevalent among strains isolated at discharge (83.6%) than those isolated at admission (60%); overall, SCCmec type I was isolated most frequently. The length of hospitalization was associated with colonization by MDR isolates (p < 0.005). Great genetic diversity was observed among S. epidermidis and S. haemolyticus.ConclusionsNICU represents an environment of risk for colonization by MDR CoNS. Neonates admitted to the NICU can become a reservoir of CoNS strains with the potential to spread MDR strains into the community.

Methicillin-resistant Staphylococcus aureus nasal carriage in neonates and children attending a pediatric outpatient clinics in Brazil

BACKGROUND In Latin America, few studies have been carried out on methicillin-resistant Staphylococcus aureus carriage in the pediatric population. We conducted a survey of nasal S. aureus carriage in neonates and in children attending the pediatric outpatient clinics in a large Brazilian city with high antimicrobial consumption. METHODS Pernasal swabs of neonates were collected upon admission and at discharge in four neonatal intensive care units and of children less than five years of age during outpatient visits. Methicillin-resistant S. aureus isolates were characterized for antibiotic susceptibility, mec gene presence, pulsed-field gel electrophoresis, spa type, SCCmec-type, multilocus sequence type, and presence of Panton-Valentine leukocidin genes. RESULTS S. aureus was carried by 9.1% and 20.1% of the 701 neonates and of 2034 children attending the outpatient clinics, respectively; methicillin-resistant S. aureus carriage was detected in 0.6% and 0.2%, of the these populations, respectively. Healthcare-associated methicillin-resistant S. aureus strains found in neonates from neonatal intensive care units and outpatients were genetically related to the Brazilian (SCCmec-III, ST239) and to the Pediatric (SCCmec-IV, ST5) clones. Community-associated methicillin-resistant S. aureus was only detected in outpatients. None of the methicillin-resistant S. aureus strains contained the Panton-Valentine leukocidin gene. Methicillin-resistant S. aureus strains related to the Brazilian clone showed multidrug resistance pattern. CONCLUSIONS Despite the high antibiotic pressure in our area, and the cross transmission of the healthcare-associated methicillin-resistant S. aureus clones between neonatal intensive care units and outpatients, the prevalence of methicillin-resistant S. aureus carriage is still low in our setting.

Molecular Epidemiology of Microorganisms Isolated from Food Workers and Enteral Feeding of Public Hospitals

UNLABELLED This study aimed to compare strains of Staphylococcus aureus and E. coli isolated from food workers and enteral diet samples obtained from 2 public hospitals (H1/H2) in Goiania, Goias, Brazil, by the means of antibiogram and pulsed field gel electrophoresis (PFGE). In the H1, strains of S. aureus were present in 2 enteral diet samples and in 13 food worker swabs. Strains of E. coli were found in an enteral diet sample from H1 and in 2 enteral diet samples from H2 and in 6 food worker swabs in the H1 and in 12 food worker swabs from H2. According to the antibiogram, the 6 susceptibility profiles (A to F) of 15 S. aureus strains colonizing personnel and enteral feeding did not allow the identification of the probable source of diet contamination. All 20 E. coli strains isolated from the H1 and H2 were grouped in 4 phenotypic profiles (A to D). The phenotypes A (H1) and C (H2) showed the same profile for microorganisms isolated from handlers and diets, suggesting more phenotypic similarity among these samples. PFGE genotyping showed that S. aureus isolates from diets were related to a single strain isolated from a food worker suggesting that in this case the reason for the diet contamination may be a result of food handling. The food worker appears to be the most probable source of E. coli contamination for enteral feeding from H2. This fact emphasizes on the food workers as a risk of bacterial transmission for the diets and that the diet chain production must be controlled. PRACTICAL APPLICATION The study emphasizes the importance of monitoring the enteral diet microbiological quality and the factors associated to its contamination. The study highlights the use of molecular biology as an instrument to correlate strains to determine the origin of the final product contamination.

Molecular characterization of Listeria monocytogenes isolated from animal products in a city of Northern Brazil

Listeria monocytogenes, a foodborne pathogen causes listeriosis, a fatal disease in about 30% of cases that affects mainly immunocompromised persons. The aim of this research was to characterize L. monocytogenes pulsed-field gel electrophoresis (PFGE) types isolated from meat products collected at public markets in Araguaina city, TO. Sixty samples of raw ground beef and frescal sausage were analyzed during the second half of 2008. Five out of 30 samples (16.7%) of raw ground beef tested positive for L. monocytogenes, three of which were classified as serotype 1/2b and two as serotype 4b. Among the 30 samples of sausage collected, two strains of L. monocytogenes were isolated (6.7%), one of them belonging to serotype 1/2a and the other belonging to serotype 1/2b. The restriction enzymes used were ApaI and SmaI. Similarities among the strains were determined by Dice coefficient. The macro restriction profile obtained by using SmaI enzyme allowed the distribution of seven strains in two clusters, two pulsotypes and two subtypes. The result indicates that L. monocytogenes isolates, belonging to serotype 4b, 1/2a and 1/2b, are strongly correlated within the same serotype group, and in some cases among different serotypes, suggesting that they have a common source.

Methicillin-resistant Staphylococcus sp. colonizing health care workers of a cancer hospital

The aim of the study was to analyze epidemiological and microbiological aspects of oral colonization by methicillin-resistant Staphylococcus of health care workers in a cancer hospital. Interview and saliva sampling were performed with 149 health care workers. Antimicrobial resistance was determined by disk diffusion and minimum inhibitory concentration. Polymerase Chain Reaction, Internal Transcribed Spacer-Polymerase Chain Reaction and Pulsed Field Gel Electrophoresis were performed for genotypic characterization of methicillin-resistant Staphylococcus. Risk factors were determined by logistic regression. Methicillin-resistant Staphylococcus colonization prevalence was 19.5%, denture wearing (p = 0.03), habit of nail biting (p = 0.04) and preparation and administration of antimicrobial (p = 0.04) were risk factors identified. All methicillin-resistant Staphylococcus were S. epidermidis, 94.4% of them had mecA gene. Closely related and indistinguishable methicillin-resistant S. epidermidis were detected. These results highlight that HCWs which have contact with patient at high risk for developing infections were identified as colonized by MRSE in the oral cavity, reinforcing this cavity as a reservoir of these bacteria and the risk to themselves and patients safety, because these microorganisms may be spread by coughing and talking.

Pseudomonas spp. ISOLATED FROM THE ORAL CAVITY OF HEALTHCARE WORKERS FROM AN ONCOLOGY HOSPITAL IN MIDWESTERN BRAZIL

This cross-sectional study, performed in an oncology hospital in Goiania, aimed to characterize the prevalence of oral colonization and antimicrobial susceptibility of Pseudomonas spp. isolated from the saliva of healthcare workers. Microorganisms were subjected to biochemical tests, susceptibility profile, and phenotypic detection. Of 76 participants colonized with Gram negative bacilli, 12 (15.8%) harbored Pseudomonas spp. Of all isolates, P. aeruginosa (75.0%), P. stutzeri (16.7%), and P. fluorescens (8.3%), were resistant to cefoxitin, and therefore likely to be AmpC producers. The results are clinically relevant and emphasize the importance of surveillance to minimize bacterial dissemination and multiresistance.