No abstract

INTRODUCTION β-Lactams are a group of antibiotics acting on the cell wall of a bacterial cell. These include the penicillins, cephalosporins, carbapenems and monobactems. These bind to and inhibit the carboxypeptidases and transpeptidases. All beta-lactam based on a common chemical structure: beta-lactam nucleus. From this nucleus there are four families: penicillins, cephalosporins or cephem, carbapenem, monobactams. Beta-lactam have a synergistic effect when administered with aminoglycosides and have an additive effect when administered together with fluoroquinolones. Resistance to beta-lactams can occur by three mechanisms: the target protein modification,

Cystic fibrosis (CF) is the most common autosomal recessive genetic disease caused by mutation of the CFTR gene. In Romania, CF disease has an estimated a prevalence of 1 case per 2500 live births. Approximately 50% of children die in early life, so the exact number of CF patients in our country remains unknown as no national patient registry exists. This situation has limited our knowledge about the disease progression. Complicated with P. aeruginosa is giving long progressive diseases and often aggravates morbidity and mortality.The aim of the study was to phenotypically frame the P. aeruginosa strains, according to their antibiotic susceptibility profile in order to administer more precisely the antibiotics and to avoid development of multidrug-resistant strains.After the diagnosis of CF, the patients return to a medical control at every 3 months. The sputum samples are collected from these patients, in order to perform the bacteriological examination and the DST test. This study was performed during 1 year (01.01-31.12.2015), and all the sputum samples were cultivated on usual and on special culture media to establish more precisely the type of isolated bacteria. The confirmation was performed using the API 20 NE biochemical test and classified in resistance phenotypes according to CLSI 2015 standards.The study population was represented by 85 infants with CF, from which we isolated 364 bacterial strains. 10.16% of the total of bacterial strains were represented by P. aeruginosa. A major problem represents the repeated antibiotic treatments, this being favourable for the emergence of resistant strains. Antibiotic resistance is currently one of the most important problems faced by clinicians. (7) Multidrug-resistant (MDR) strains of P. aeruginosa were identified in this study and we highlighted that this strains limits the antimicrobial treatment and is shortening the patient's life. (9)

ESBL-producing organisms pose unique challenges to clinical microbiologists, clinicians, infection control professionals and antibacterial-discovery scientists. Although the prevalence of ESBLs is not known, it is clearly increasing, and in many parts of the world, 10-40% of strains of E. coli and K. pneumoniae express ESBLs (Rupp and Fey, 2003).The aim of this study was to assess the prevalence of ESBL-positive strains of E. coli and K. pneumoniae in cows with clinical signs of endometritis that were treated exclusively with Oxytetracicline for both diseases of the genital area as well as other bacterial infectious diseases.The study population included 35 Romanian Black Pied cows with clinical signs of endometritis within a farm in North Eastern of Romania. The samples were harvested using sterile cotton swabs that have been further microbiologically processed. For the phenotypic confirmation of the isolated ESBL strains, were used the combined disk test (CLSI, 2014) and the Oxoid Brilliance chromogenic ESBL Agar medium. The taxonomic classification of the isolated colonies was carried out by testing some minimal biochemical characteristics by using the MIU and TSI tests.A total of 47 bacterial strains were isolated from uterine secretions, derived from the 35 cows included in this trial. From the total of 47 isolated bacterial strains, 17 belonged to E. coli and K. pneumoniae species, from which, 6 of them were confirmed as being ESBL-positive.In this preliminary study, by phenotypic methods was confirmed a prevalence of 35.3% for the ESBL strains of E. coli and K. pneumoniae, which requires further research to confirm by molecular biology the identification of ESBL resistance genes, but also for the plasmids encoding these gene transmission.

The animals producing food have become an increasing reservoir of extended spectrum beta-lactamase producing Enterobacteriaceae. The calves and cows are exposed to a greater quantity of antibiotics, but the data concerning the prevalence of ESBL-producing Enterobacteriaceae are not enough, in comparison with other species of animals used for human consumption, such as birds (Hordijk et al., 2013).The aim of this study was to determine the prevalence of ESBL-producing E. coli involved in some episodes of colibacilosis in calves. Faeces samples were collected from 33 calves with the age ranging between 1-2 weeks and that presented clinical signs of colibacilosis. The samples were collected in a sterile medium for the taxonomic isolation and identification of the etiological agent involved, the ESBL screening being conducted subsequently using the ESBL Agar Oxoid Brilliance chromogenic medium. The phenotypic confirmation of the ESBL-producing strains was conducted in accordance with the CLSI (2014) standard through the combined disc method. Following the tests conducted, out of the 33 strains of isolated E. coli, 9 (27, 27%) were phenotypically confirmed as being ESBL strains.The studies that were previously conducted on the dairy farms have pointed out that the young calves rapidly acquire bacterial strains resistant to antibiotics that are often ESBL strains (Hordijk et al., 2013). The prevalence obtained by us, as well as an insufficient quantity of information concerning the antimicrobial resistance on this segment of species of animals used for the human consumption, support conducting a more thorough study, as well as the identification of ESBL resistance genes, but also of the plasmids that encode the transmission of these genes.