Antimicrobial Susceptibility Testing for Corynebacterium Species Isolated from Clinical Samples in Romania.

Antimicrobial resistance is one of the most important public health issues. Besides classical multidrug resistance species associated with medical care involved in superficial or invasive infections, there are strains less commonly associated with hospital or outpatient setting's infections. Non-diphtheria Corynebacterium spp. could produce infections in patients with or without immune-compromised status. The aim of our study was to determine the susceptibility to antimicrobial agents to Corynebacterium spp. from clinical samples collected from Romanian hospitalized individuals and outpatients. Twenty Corynebacterium strains were isolated and identified as Corynebacterium striatum (n = 7), Corynebacterium amycolatum (n = 7), C. urealyticum (n = 3), Corynebacterium afermentans (n = 2), and Corynebacterium pseudodiphtheriticum (n = 1). All isolates have been tested for antibiotic susceptibility by standardized disc diffusion method and minimal inhibitory concentration (MIC) tests. Seventeen isolates demonstrated multidrug resistance phenotypes. The molecular support responsible for high resistance to quinolones for ten of these strains was determined by the detection of point mutation in the gene sequence gyrA.

Seroprevalence study of anti diphtheria antibodies in two age-groups of Romanian adults.

BACKGROUND: Diphtheria represents a serious infectious disease with high epidemic potential. It is a vaccine preventable disease (a minimum vaccine coverage of 95% for children of 1 year and 90% in adults could prevent the disease). Diphtheria vaccination is included in the National Immunization Program (NIP). Complete vaccination for children consists in DTaP (diphtheria toxoid, tetanus toxoid and acellular pertussis vaccine) vaccine administration from the age of 2 months until 4 years and dT vaccine (tetanus toxoid and a reduced dose of diphtheria toxoid) at 14 years old. The aim of this paper was to highlight the protection against diphtheria of an age segment of the Romanian adult population (20 to 39 years old) using a seroprevalence study. MATERIALS AND METHODS: The Romanian subjects were selected from two age groups: 20-29 years (n = 219) and 30-39 years (n = 229), representative for all counties of Romania. The commercial kit Anti-Diphtheria Toxoid ELISA (IgG) (EUROIMMUN) was used to detect the antibodies of IgG class against diphtheria toxoid in the sera obtained from our subjects. RESULTS: We detected a 56.6% rate of positive sera (> 0.1 IU/ml--protection level) for the 20-29 age group and 31.7% positivity for the 30-39 age group. These data show a low protection level against diphtheria of the Romanian adult population, which decreases with age. The serologic data on preventable vaccine diseases are useful in order to evaluate the success of the immunization programs.

Phenotypic and genotypic characterization of Staphylococcus aureus strains isolated from a familial foodborne outbreak.

Although Staphylococcus aureus is frequently reported among the common causative agents of foodborne diseases in Europe, very little is known about the strains involved in staphylococcal food-poisoning outbreaks in our region. Therefore, the aim of this study was to characterize the staphylococcal strains recovered from an autochthonous food-poisoning familial outbreak through phenotypic and genotypic methods. Ten S. aureus strains from food and human sources, submitted to the reference laboratory, were tested for susceptibility to 18 antibiotics by disk diffusion and production of enterotoxins A, B, C, D using a reversed passive latex-agglutination assay, and further analyzed by multiplex PCR-based assays for the detection of sea, seb, sec, sed, see, seh, sei, sej, sem, and sen genes. Phage typing, pulsed-field gel electrophoresis (PFGE) and spa typing were performed for evaluating the clonal relatedness of the isolates. Isolates from stool samples and food displayed a similar antibiotic resistance profile, produced enterotoxin B, were PCR-positive for seb, sei and sem genes, and revealed an indistinguishable SmaI macrorestriction pattern at PFGE analysis, suggesting that incriminated food was most likely the source of this food poisoning outbreak. The isolate which expressed a different antibiotic susceptibility profile and tested negative at the screening for enterotoxin production carried seh gene and was discriminated by a nine-band different PFGE profile from the rest. Combined phenotypic and genotypic profiles by multiple typing are necessary to explore key features of epidemic strains and start to lead to a better understanding of the local epidemiology of infections due to toxigenic S. aureus strains.

Antimicrobial activity of copper and silver nanofilms on nosocomial bacterial species.

Contaminated surfaces are possible vehicles in infection transmission. It is known that both Copper (Cu) and Silver (Ag) efficiently inactivate microbes by direct contact. Aiming at using these metals for benefitting from their antimicrobial effect, but to avoid subsequent toxic effects, we evaluated the antimicrobial activity of nanometric thin Silver and Copper films covering less expensive materials. Using a modified version of the Japan Industrial Standard JIS Z 2801:2000, we demonstrated the antimicrobial activity of the surfaces covered with metal ions nanofilms on microorganisms possibly involved in nosocomial infections and on Bacillus anthracis, bacteria with possible implication in bioterrorist attacks. Copper covered surfaces proved to have better antimicrobial activity than Silver surfaces. Silver covered surfaces showed better activity on Gram negative bacteria than on Gram positive cocci. Going deeper with studies on antimicrobial effects using new methods with better direct and/or functional discriminatory capacity is needed in order to provide additional information on the mechanisms of Silver and Copper nanofilms antimicrobial activity.

Antimicrobial activity of plant essential oils against bacterial and fungal species involved in food poisoning and/or food decay.

The currative properties of aromatic and medicinal plants have been recognized since ancient times and, more recently, the antimicrobial activity of plant essential oils has been used in several applications, including food preservation. The purpose of this study was to create directly comparable, quantitative data on the antimicrobial activity of some plant essential oils prepared in the National Institute of Research-Development for Chemistry and Petrochemistry, Bucharest to be used for the further development of food packaging technology, based on their antibacterial and antifungal activity. The essential oils extracted from thyme (Thymus vulgaris L.), basil (Ocimum basilicum L.), coriander (Coriandrum sativum L.), rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.), fennel (Foeniculum vulgare L.), spearmint (Mentha spicata L.) and carraway (Carum carvi L.) were investigated for their antimicrobial activity against eleven different bacterial and three fungal strains belonging to species reported to be involved in food poisoning and/or food decay: S. aureus ATCC 25923, S. aureus ATCC 6538, S. aureus ATCC 25913, E. coli ATCC 25922, E. coli ATCC 35218, Salmonella enterica serovar Enteritidis Cantacuzino Institute Culture Collection (CICC) 10878, Listeria monocytogenes ATCC 19112, Bacillus cereus CIP 5127, Bacillus cereus ATCC 11778, Candida albicans ATCC 10231, Aspergillus niger ATCC 16404, Penicillium spp. CICC 251 and two E. coli and Salmonella enterica serovar Enteritidis clinical isolates. The majority of the tested essential oils exibited considerable inhibitory capacity against all the organisms tested, as supported by growth inhibition zone diameters, MICs and MBC's. Thyme, coriander and basil oils proved the best antibacterial activity, while thyme and spearmint oils better inhibited the fungal species.