Ceftazidime/Avibactam-Resistant Klebsiella pneumoniae subsp. pneumoniae Isolates in a Tertiary Italian Hospital: Identification of a New Mutation of the Carbapenemase Type 3 (KPC-3) Gene Conferring Ceftazidime/Avibactam Resistance

Several Klebsiella pneumoniae carpabenemase (KPC) gene mutations are associated with ceftazidime/avibactam (CAZ-AVI) resistance. Here, we describe four Klebsiella pneumoniae subsp. pneumoniae CAZ-AVI-resistant clinical isolates, collected at the University Hospital of Tor Vergata, Rome, Italy, from July 2019 to February 2020. These resistant strains were characterized as KPC-3, having the transition from cytosine to thymine (CAC-TAC) at nucleotide position 814, with histidine that replaces tyrosine (H272Y). In addition, two different types of KPC gene mutations were detected. The first one, common to three strains, was the D179Y (G532T), associated with CAZ-AVI resistance. The second mutation, found only in one strain, is a new mutation of the KPC-3 gene: a transversion from thymine to adenine (CTG-CAG) at nucleotide position 553. This mutation causes a KPC variant in which glutamine replaces leucine (Q168L). None of the isolates were detected by a rapid immunochromatographic assay for detection of carbapenemase (NG Biotech, Guipry, France) and were unable to grow on a selective chromogenic medium Carba SMART (bioMerieux, Firenze, Italy). Thus, they escaped common tests used for the prompt detection of Klebsiella pneumoniae KPC-producing.

Biofilm formation by Candida albicans and Candida glabrata isolated from urine specimens of diabetic Iraqi women

Biofilms are multicellular communities where microorganisms are grown and form an extracellular matrix that protects the pathogenic microorganisms from the immunity system and antimicrobial agents. This study is aimed to identify Candida spp. isolated from urine specimens by using traditional techniques, germ tube, growth on corn meal agar medium and chromogenic medium then determine the ability of isolates to producing biofilm by tube method (TM) and congo red agar method (CRA). In our study urine specimens were obtained from 174 diabetic females in the period of six months at the Al-Wafa Specialized Center for Diabetes and Endocrinology, Mosul city, Iraq. Out of the total 174 specimens, yeast species were isolated from 56 (32.2 %) specimens. Out of the 56 isolates, 50 isolates were positive for Candida spp., especially C. glabrata which appeared maximum in 30 isolates (60 %) and followed by C. albicans 18 isolates (36%) and C. krusei 2 isolates (4 %). In the TM method for biofilm detection, C. albicans showed 16 isolates (88.9%) positive for biofilm formation followed by 29 isolates (96.7%) of C. glabrata. Furthermore, in the CRA method, all isolates (100%) of C. albicans were negative followed by 27 isolates (90%) of C. glabrata, whereas only 3 isolates (10%) of C. glabrata were positive. We can conclude that TM is the best conventional method and is sensitive to detect biofilm-forming yeast when compared with the CRA method.

Systemic antimycotic therapy of patients with mycosis of the oral mucosa and periodontal Сandida etiology

Candidiasis is the most common mycosis. Оral candidiasis occurs in the form of stomatitis, including the so-called prosthetic stomatitis. Somewhat less often, fungi of the genus Candida are detected with gingivitis and periodontitis, manifestations of red lichen planus on the oral mucosa.The purpose of the work: to analyze the results of mycological studies and determine the sensitivity of fungi isolated from the oral cavity in vari-ous oral pathologies to the main antimycotics, as well as the formation on this basis of an algorithm for antimycotic therapy of candidal lesions of the oral mucosa and periodontium.Material and methods. The paper uses the results of studies of patients with candidiasis of the oral mucosa (127 patients), prosthetic stomatitis (136 patients), candida-associated periodontitis (168 patients). Primary inoculation was performed quantitatively on Sabouraud’s medium and duplicated on M1297 chromogenic medium (Himedia Labs, India).To study the biofilm formed on the oral mucosa, fixed preparations of gold-coated scrapings were prepared for scanning electron microscopy, which was performed using a Quanta 200 3D bi-beam microscope (USA). Sensitivity to antimycotics was assessed using the traditional method of disks.The results of the study. When studying the species composition of yeast-like fungi isolated from the material, it was found that the species C. albicans was isolated in 80% of patients, in association with other species: C. Krusei, C. guilliermondii and C. glabrata. The second place was taken by the species C. Krusei, which was detected in 13.3% of patients. Representatives of this genus of yeast fungi are characterized by the formation of a biofilm with a pronounced mantle, which protects the microorganism from aggressive factors, including antimycotics and antiseptics. All the studied preparations showed fungicidal activity against these strains of yeast-like fungi. When registering the results, it was found that the most pronounced sensitivity of yeast-like fungi of this species was to drugs from the group of azole derivatives. The most pronounced antifungal activity was noted by us in voriconazole.Conclusion. Based on the obtained data, an algorithm of systemic antimycotic therapy for oral candidiasis has been developed.

Utility of Chromogenic Medium in Characterization of Enterococci in Urinary Tract Infection and Phenotypic Detection of Their Virulence Factors

Introduction: Enterococci from being intestinal commensals have evolved in becoming pathogens and are associated with significant morbidity and mortality Aims & Objectives: This study was done to speciate the uropathogenic Enterococci using the chromogenic medium and to determine the antibiogram also to detect virulence factors phenotypically. Materials and methods: The study included a total of 30 uropathogenic Enterococci isolated over 6 months. Speciation was done using HiCrome Enterococcus faecium agar base. Antibiotic sensitivity was done by the Kirby Bauer Disc Diffusion method as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Among the virulence factors hemolysin, haemagglutination, and gelatin liquefaction tests were done. Results: Amongst the 30 enterococci isolates, 17 were Enterococcus faecalis (E. faecalis) (56.66%) & 13 were Enterococcus faecium (E. faecium) (43.33 %). 100% of the Enterococcus species were sensitive to Vancomycin & Teicoplanin. 66.67% of the Enterococci showed hemolysis, 10% haemagglutination, and 43.33% gelatinase property. Conclusion: Most common isolated species were Enterococcus faecalis. The changing patterns of antibiotic sensitivity to Enterococci in patients with urinary tract infection possess difficulty in selection of the antibiotics. Failure to synergistic therapy is seen in cases of resistance to High-level Gentamicin. Therefore, speciation and antibiotic sensitivity patterns will help in setting up an empirical therapy and thereby help in the reduction of morbidity and mortality. Key words: Antibiotic susceptibility, Chrome agar, Enterococcus species, virulence factors.

METHODS OF INDICATION OF E. COLI AND E. COLI GROUP BACTERIA IN MEAT

The article provides an overview of methods for detecting bacteria of the Escherichia coli group, including E. coli. This group of microorganisms is one of the main standardized indicators when assessing the quality of food products of animal origin. Analysis of microbiological studies of chilled beef meat samples showed that when determining the presence of BGKP in samples, using traditional and modern methods of analysis, the results do not differ significantly. For the differentiation of enterobacteria, Endo's medium and a selective agar chromogenic medium Chromocult Coliform Agar (Merck, Germany) were used. The amount of BGKP in 1 cm3 of meat products varied from 0.3 × 102 CFU / cm3 to 1.6 × 102-1.8 × 102 CFU / cm3. When microcopying smears in all samples, small rods with rounded ends were found, according to Gram they were negatively stained. When growing on Endo agar, colonies of red color with a metallic sheen were noted; on a chromogenic medium, the growth of violet colonies was noted. During the tests, microorganisms were identified from the samples, representatives of the genera: Escherichia, Enterobacter, Citrobacter. The use of modern methods of analysis made it possible to reduce the labor costs that were spent on the preparation of media, and also made it possible to exclude the stages of confirmatory biochemical tests, thanks to the use of culture media with markers of specific enzymatic activity.

Analysis of the results of microbiological studies of samples of chilled pork and beef meat using traditional and advanced techniques

The article analyzes microbiological studies of meat raw materials obtained using traditional methods of determination and using ready-made test systems. The most promising direction for the development of modern sanitary microbiology at the present time is the use of modern chromogenic medium and ready-made test systems.