Susceptibility testing of Streptococcus pneumoniae and Viridans streptococcal isolates against: quinolones, oxazolidinones and glycopeptides.

UNLABELLED: The aim of this study was to test the susceptibility of 100 strains (pneumococci and viridans streptococci) isolated from oral and respiratory tract infections and their complications, against one antibiotic of each of the following classes: quinolones, oxazolidinones and glycopeptides. MATERIAL AND METHODS: The Etest has been used in order to investigate the susceptibility of the isolates against levofloxacin, linezolid and vancomycin. RESULTS AND CONCLUSIONS: As expected, the results of the study indicated that all isolates were susceptible to linezolid and vancomycin. In contrast to the pneumococcal isolates, which were all susceptible to levofloxacin, 10% of the viridans strains showed resistance to this quinolone. When fluoroquinolones are needed as an alternative to the beta-lactam antibiotics in infections in which oral streptococci are involved, the in vitro susceptibility testing is required.

Contribution towards developing a new semi-selective medium for Streptococcus anginosus group.

UNLABELLED: The aim of this study was to develop a new selective medium for isolation of Streptococcus anginosus group (SAG) strains, by adding sulphamethazine and aztreonam as selective agents at Mitis-Salivarius agar (MSA), the medium commonly used for recovery of oral streptococci from oral samples. MATERIAL AND METHOD: The evaluation of Mitis-Salivarius--sulphamethazine--aztreonam agar (MSSAA) for SAG selectivity was performed by testing the growth of type strains and laboratory-stored clinical isolates of different oral streptococcal species on this medium and also by investigating the SAG recovery on MSSAA in comparison with MSA and the growth inhibition of non-SAG strains from 100 saliva and 11 pus samples (collected from healthy young subjects and from paediatric patients with upper respiratory tract infections, respectively) on MSSAA. RESULTS: The same SAG recovery rate was obtained on both MSSAA and MSA, while non-SAG strains failed to grow on the novel medium, except for enterococci. The results of the present study have indicated that MSSAA is a suitable medium for selecting SAG isolates from clinical specimens.

[Anaerobic Gram-negative bacilli involved in the etiopathogeny of the abscesses of superficial fascial spaces of the face and neck]. / Bacili Gram-negativi anaerobi implicati in etiopatogenia abceselor cu localizare in lojile superficiale ale fetei si gâtului.

UNLABELLED: The aim of this study was to isolate and identify at species level the strains of anaerobic Gram-negative bacilli (GNB) from pus samples collected in patients with abscesses of fascial spaces of the face and neck. Microscopy of Gram-stained smears and cultures were performed in each specimen. The strictly anaerobic GNB strains were identified using the conventional methods of diagnosis and the Rapid ID 32 A system. In addition, the other strains isolated in association with these bacteria were identified at least to genus level. The 28 anaerobic GNB isolates belonged to: Fusobacterium nucleatum and different species of Prevotella (4 species) and Bacteroides (3 species). CONCLUSIONS: The anaerobic GBN strains were recovered--either alone or in association with other migroorganisms--in more than half of all investigated samples and represented about 40% of all isolates. The most frequently isolated species were P> melaninogenica and B. ureolyticus.

Control of blood-transmitted infections in dentistry.

As knowledge has accumulated on the blood-transmitted pathogenic agents, the contact with biological fluids (blood, plasma, saliva, etc.) from apparently healthy individuals has started to be regarded as a real professional risk for dentists. Theoretically, exposure to a contaminated biological specimen may have as a consequence transmission of infection from patient to dentist, from dentist to patient and from patient to patient via inadequately decontaminated and sterilized dental equipment. The present study is concerned with the analysis of the specific conditions that favor the occurrence of the epidemic process, the estimation of the risk degree of transmission of infections caused by hepatitis B, C viruses as well as of HIV infection in Romania. The data for the study were collected using two processes. First a self reporting survey and secondly an experimental procedure were performed. The testing of dentists' knowledge of blood transmissible diseases and infection control in their offices were performed using a questionnaire with 129 questions. The professional incidents/accidents representing a potential risk were counted using a questionnaire (with 37 questions). Serological markers were tested with ELISA kits. The monitoring of sterilization was accomplished with a questionnaire and biological tests. Many conclusions result from the study. There is an extremely reduced probability and infection transmission from the dentist to the patient. The transmission of infection from the patient to the dentist represents a low risk (for all that, the risk should not be minimized). The rigorous control and observation of infection prevention measures in dental offices is necessary to stop the infection transmission from patient to patient. The dentists' postgraduate training in infection control measures should be completed with knowledge regarding the blood transmissible infections epidemiology. Learning more about the epidemiological process enables the dentists to avoid wrong attitudes and behaviors.

Susceptibility testing of Streptococcus mitis group isolates.

BACKGROUND & OBJECTIVES: Suppurative oral and maxillofacial infections are usually mixed infections due to aerobic and anaerobic bacteria, most frequently by oral streptococci and antimicrobial treatment is necessary for such infections. The aim of this study was to investigate the antimicrobial susceptibility of Streptococcus mitis group strains isolated from Romanian patients with different oral and maxillofacial infections. METHODS: Eighty-five isolates belonging to S. mitis group isolated from pus samples were identified at species level by the Rapid ID 32 STREP system. The E test was used to determine the susceptibilities of the isolates to penicillin, ampicillin, cefotaxime, erythromycin, clindamycin, chloramphenicol and tetracycline. RESULTS: Of the 151 samples studied, 85 isolates belonged to S. mitis group. The minimum inhibitory concentration (MIC) values (mg/l) ranged from 0.016-0.75 for penicillin, 0.016-2 for ampicillin, 0.016- 1 for cefotaxime, 0.016-4 for erythromycin, 0.016-0.047 for clindamycin, 0.5-4 for chloramphenicol and 0.047-256 for tetracycline. INTERPRETATION & CONCLUSION: The low susceptibility and the resistance to some commonly used antibiotics found in this study indicated a need for a careful surveillance of the susceptibility pattern of oral streptococci isolates of clinical significance. Clindamycin and chloramphenicol might be suitable alternative agents in treatment of oral and maxillofacial infections involving penicillin-resistant bacteria and in case of patients with hypersensitivity to beta-lactam antibiotics.

[Prevotella species involved in the onset of superficial face and neck abscesses]. / Specii de Prevotella implicate în producerea abceselor cu localizare în lojile superficiale ale fetei si gâtului.

The aim of the study was to identify at species level the Prevotella strains from 30 pus samples collected by needle aspiration in patients with abscesses of fascial spaces of the face and neck. Microscopy of Gram-stained direct smear and cultures on selective and nonselective media incubated aerobically and anaerobically were performed in each pus specimen. All strains of Gram-negative strictly anaerobic bacilli were identified to genus and species level using conventional methods of diagnosis and the Rapid ID 32 A system (BioMérieux, Marcy-l'Etoile, France). The Prevotella isolates were recovered (alone or in association with other bacteria) in 46.6% of the investigated specimens and were represented in reverse order of frequency by the following species: P. melaninogenica, P. denticola, P. oralis and P. loescheii. In conclusion, the rate of Prevotella isolation was relatively high and the most frequently isolated species was P. melaninogenica (followed by P. denticola), while no P. intermedia was found.

[Phenotypical characterization of some strains of anginosus streptococci isolated from superficial face and neck abscesses]. / Caracterizarea fenotipica a unor tulpini de streptococi din grupul anginosus izolate din abcese cu localizare în lojile superficiale ale fetei si gâtului.

The aim of the present study was to identify at species level and to characterize the strains of streptococci belonging to anginosus group isolated from 30 pus samples collected from patients with abscesses of fascial spaces of the face or neck. The identification of facultatively anaerobic Gram-positive cocci in chains at genus level was made by conventional diagnosis methods and at species level by the help of Rapid ID 32 STREP system. The cultural, biochemical and antigenic (limited at Lancefield Group identification by Slidex Strepto-Kit) characterization was performed in the mean time with the species identification. The anginosus streptococcal strains were isolated either in association with other bacteria or in pure culture and S. anginosus isolates clearly predominated. As expected, the anginosus streptococcal strains were found to be heterogeneous regarding the cultural, biochemical and antigenic features.

Streptococci species of anginosus group isolated from oral and maxillofacial infections.

The aim of the study was to isolate and identify at species level streptococci strains of anginosus group in pus samples collected from 110 patients with oral and maxillofacial (OMF) infections. Gram-stained smears and cultures on selective and nonselective media were done from each of the 111 pus samples (2 samples were collected from one of the patients, who presented 2 oral abscesses at the same time). The isolates were identified on the basis of cultural and biochemical characteristics. Speciation of the anginosus group isolates was performed using the Rapid ID 32 Strep system (Bio Mérieux, France). Fourty-four anginosus group strains were isolated from 42 patients. Fourty of these isolates were identified as Streptococcus anginosus (2 nonidentical isolates were found in 2 patients), 3 isolates as Streptococcus constellatus and only one as Streptococcus intermedius. The study confirmed that the anginosus group is often involved in OMF infections alone or in association with other aerobic and/or anaerobic bacteria. In the investigated cases, Streptococcus anginosus was by far the most frequently isolated species within the anginosus group.

Antimicrobial susceptibility of some streptococci strains of anginosus group isolated from oral and maxillofacial infections.

Streptococci strains of the anginosus group isolated from various oral and maxillofacial infections (OMF) were screened for their susceptibility to the following antimicrobial agents: benzylpenicillin, ampicillin, oxacillin, cephalothin, ceftazidime, cefotaxime, cefuroxime, erythromycin, clindamycin, tetracycline, chloramphenicol, vancomycin and trimethoprime-sulphamethoxazole. The isolates were susceptable to: clindamycin, chloramphenicol, vancomycin and all beta-lactam antibiotics, except ceftazidime to which 54.5% of the strains showed intermediate susceptibility. Intermediate susceptibility to tetracycline was found in 11.3% of the strains, whereas resistance to the same antibiotic was demonstrated in 61.4%. Resistance to erythromycin and trimethoprime-sulphamethoxazole was of 2.3% for both. In conclusion, penicillin is the drug of choice in infections caused by streptococci of the anginosus group.

Infection control practices and compliance to national recommendations among dentists in Romania.

The aim of this study was to measure dental office compliance with current Romanian infection control regulations. A questionnaire was completed and returned from 61 randomly selected offices (32 private and 29 public with 94 dentists), where the sterilizers were also biologically monitored. Results indicated that with few exceptions, infection control practices in public and private offices were the same, with compliance on sterilising reusable instruments. Private offices monitored their sterilizers more frequently and had much newer equipment. Gowns were universally worn, but use of gloves, masks and protective eye-wear showed non-compliance with less than 10 per cent of the offices using personal protective equipment for all patients. Cost was the deciding factor. Predominant environmental disinfectants were alcohol and bleach. Offices were in compliance as to the use of disposable anaesthetic needles and carpules. Dentists reported reluctance to be vaccinated against hepatitis B even when offered free immunizations (6.4 per cent) and only 18.1 per cent of dentists had received any infection control training in the last three years. Results indicate that offices were in compliance for most national regulations. However, there are no recently published standards for dentistry in Romania concerning disinfectants or continuing education. Comparison with the literature indicates comparable compliance with recommended national infection control procedures for Romanian dentists as for dentists in other countries.

Phenotypic characterization of some anginosus group isolates from oral and maxillofacial infections.

The aim of this study was to briefly characterize serologically, biochemically and from the cultural point of view some anginosus group isolates found in pus samples collected from patients with oral and maxillofacial infections. Cultural characterization was done by studying the culture odor, the colony size and aspect, and hemolysis type on Columbia bood agar (BA). Lancefield grouping was made on cards using the rapid latex-agglutination test (Slidex Strepto-Kit, Bio Mérieux, France). The biochemical characterization was performed at the same time with the speciation by the Rapid ID 32 Strep system (Bio Mérieux, Marcy-l'Etoile, France). The anginosus group isolates were phenotypically heterogenic. Based on phenotypic description, nonidentical anginosus group isolates were found in the same patient sample.