INVESTIGATION OF TIGECYCLINE SUSCEPTIBILITY OF MULTIDRUG-RESISTANT ACINETOBACTER BAUMANNII ISOLATES BY DISC DIFFUSION, AGAR GRADIENT AND BROTH MICRODILUTION TESTS.

The use of tigecycline is becoming increasingly important because of the high levels of antibiotic resistance in Acinetobacter baumannii (A. baumannii) isolates. In this prospective study, multidrug-resistant A. baumannii isolates were obtained from various tissue and fluid samples of patients admitted to or treated at various departments and tested in Laboratory of Microbiology, Duzce University Medical Faculty between January 2013 and December 2015. Tigecycline resistance in multidrug-resistant A. baumannii isolates were analyzed using the disc diffusion test (DDT), agar gradient test (AGT), and gold standard test [broth microdilution test (BMT)]. A. baumannii isolates resistant to multiple drugs were included in the study (N=94). Using the BMT method, 89 (95%), 4 (4%) and 1 (1%) A. baumannii isolates were determined as tigecycline susceptible, intermediate and resistant isolates, respectively. Using the Food and Drug Administration criteria, the rates of major error (ME), minor error (mE) and categorical agreement (CA) for DDT were 26%, 67% and 9%, respectively. In contrast, for AGT, the rates of ME, mE and CA were 0%, 4%, 95%, respectively. Tigecycline resistance as assessed by BMT showed no increase between 2013 and 2015. Accordingly, isolates found to be resistant or intermediate by DDT should be confirmed by BMT. Due to the ease of application, AGT is a safe method of detecting susceptibility.

Threat in water for drinking and domestic use: Nontuberculous mycobacteria.

Objective: Nontuberculous mycobacteria (NTM) have been recognized as a diverse group of organisms that are ubiquitous in environmental sources. In most regions of the world, NTM are not reportable as a public health disease, so epidemiological data are not easily available. However, data in published studies note increasing trends at the rate of NTM isolation from different geographic regions of the world. Increasing NTM isolation may have important public health implications. The aim of our study is the investigation of NTM from water resources and networks in Düzce, Turkey. Methods: NTM are common in water resources and water networks. They can cause waterborne infections in humans. A total of 120 water samples measured of chlorine and pH levels were decontaminated and filtered. Then, the filters were placed in the culturing media. Statistical Analysis Used: Chi-square and t-test were used for the statistical analysis. Results: NTM were detected in 20 (16.6%) samples. Nine of them (45%) were Mycobacterium fortuitum, three (15%) were Mycobacterium gordonae, three (15%) were Mycobacterium szulgai, two (10%) were Mycobacterium lentiflavum, two (10%) were Mycobacterium chelonae, and one (5%) was Mycobacterium peregrinum. Conclusions: These environmental bacteria can cause serious illnesses in both immunocompetent and especially immunocompromised individuals. For the correct treatment of these patients, it is important to determine NTM in clinical samples. Surveillance is necessary to know the source of NTM infection, to identify and type the strains, and to establish effective control measures such as disinfection, maintenance, and modernization of water systems.

[Changing Trends in Isolation Frequencies and Species of Clinical Fungal Strains: What Do the 12-years (2008-2019) Mycology Laboratory Data Tell About?] / Enfeksiyon Etkeni Mantarlarin Zamana Göre Siklik ve Tür Dagilimlarindaki Degisimler: 12 Yillik (2008-2019) Mikoloji Laboratuvari Verileri Ne Söylüyor?

The frequency and variety of infections caused by fungi are increasing. However, changes and intercenter and regional differences are observed in the distribution of fungal species over the years. It is important to update the epidemiological data in order to enable early and appropriate treatment. In this retrospective study, the number of fungi isolated from clinical samples, their distribution at the genus/ species level and the variations over the years in Hacettepe University hospital which is a regional center for patients at risk of fungal infection were investigated. For this purpose, laboratory records from 2008- 2019 were examined and 21813 fungal strains isolated from 19636 clinical samples were detected. When the first (2008-2013) and second (2014-2019) six-year periods were compared, a 2.5 fold increase was observed in the number of specimens yielding fungal growth (first period; n= 5620, second period; n= 14016). Fungi were most frequently isolated from urine (45.0%), lower respiratory tract (30.7%) and blood (6.8%) samples. Mould isolation rate in all samples increased significantly in the second six-year period (from 8.3% to 10.6%, p≤ 0.001). As expected, the most frequent yeast was Candida albicans (57.0%) and mould was Aspergillus fumigatus complex (50.4%). In the second six-year period, isolation of C.albicans (59.3% to 56.0%, p≤ 0.001) among yeasts and A.fumigatus complex (58.1% to 48.0%, p≤ 0.001) among moulds decreased significantly. In urine specimens, most common fungi were C.albicans (49.8%), Candida glabrata complex (15.6%), Candida tropicalis (8.9%) and Candida kefyr (7.5%). In lower respiratory tract specimens, the most common mould was A.fumigatus complex (51.2%), which has decreased from 63.7% in the first six years to 47.1% in the second period (p≤ 0.001). Over the same period, other Aspergillus species (from 25.5% to 34.1%, p= 0.002) and non-Aspergillus moulds (from 36.3% to 52.9%, p≤ 0.001) were increased. In blood samples, C.albicans (44.4%), Candida parapsilosis complex (21.5%) and C.glabrata complex (13.0%) were the most frequent species. In the second six-year period, the frequency of C.albicans decreased from 47.3% to 42.2% (p= 0.059) and the frequency of C.glabrata complex increased from 9.5% to 15.5% (p≤ 0.001) when compared to the first period. For the sterile specimens other than blood, the most common species were C.albicans (37.8%), C.glabrata complex (9.1%) and C.parapsilosis complex (4.7%). However, the number of fungal isolates and the distribution of the species showed great variation over the years. In our center, a substantial increase in the number of fungal strains isolated from the clinical specimens were observed over a 12-years period. In addition and similar to previously published reports, the increase of strains belonging to species with decreased antifungal susceptibility and/or species with unknown susceptibility were detected. The use of local data is required in order to implement early and appropriate antifungal treatment because of inter-center and regional differences observed in epidemiological trends regarding the distributions of fungal genera and species. Surveillance studies to be conducted with the participation of large and sufficient numbers of centers in our country, as we have done for our center, will also contribute to approaches regarding the management of fungal infections by revealing the epidemiological data in a comprehensive manner.

Seroprevalence of hantavirus and Borrelia burgdorferi in Düzce (Turkey) forest villages and the relationship with sociodemographic features

Background/aim: Hantavirus and Borrelia burgdorferi are two zoonotic agents that pose a great risk especially for people living in forest areas. This study aimed to investigate the seroprevalence of hantavirus and B. burgdorferi in forest villages of Düzce and its relationship with sociodemographic features. Materials and methods: The presence of immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against hantavirus and B. burgdorferi in serum samples was investigated via enzyme-linked immunosorbent assay (ELISA). Hantavirus IgG and B. burgdorferi IgM and IgG positivity was then validated by western blot (WB) method. Results: During the analyses, 193 serum samples were tested. Eleven (6%) cases of hantavirus IgM was found positive by ELISA. Six (3%) cases of hantavirus IgG, 3 (2%) cases of B. burgdorferi IgM, and 12 (6%) cases of B. burgdorferi IgG were found positive by WB. Borrelia burgdorferi IgG positivity was found to be higher in the 46­70 age group and it was seen that the positivity was the highest among those who lived in mud-brick houses. Conclusion: This study was the first to determine the frequency of hantavirus in the study region and it includes current data for B. burgdorferi. Consequently, it is recommended that similar studies be carried out on rodents in all the regions at risk.