Assessment of index value performance of enzyme immunoassay test in predicting the diagnosis of human brucellosis.

INTRODUCTION: Clinical presentation of brucellosis is variable. Therefore, it must be confirmed with laboratory findings. Standard tube agglutination test (STAT) is commonly used for diagnosis of brucellosis. ELISA tests differentiate between IgM and IgG antibodies. However, there are evidences revealing that they do not have sufficient specificity. This study aimed to determine an ELISA optimal index value in the diagnosis of brucellosis. METHODOLOGY: Brucella STAT and ELISA IgM/IgG tests of patients admitted to the hospital with signs and symptoms of brucellosis between January 2017 and December 2019 were evaluated in the Microbiology Laboratory. RESULTS: ELISA IgM and IgG serum median index value was significantly higher in STAT positive (1 ≥ 1:160) group (p < 0.001 for both). By ROC analysis of 117 patients, when the IgM index value was determined to be 2.44, the sensitivity, specificity, positive and negative predictive values were 85.7%, 71.4%, 60%, and 90.9%, respectively, and when the IgG index 7.85 was determined, these values were 85.7%, 53.7%, 36.7%, and 92.3%, respectively was detected. CONCLUSIONS: In this study, it was revealed that Vircell Brucella had a good clinical diagnostic performance for index value of 2.44 for IgM test kit and 7.95 for IgG test kit. If the diagnosis of brucellosis is correctly predicted with index values in Brucella IgM and IgG tests before STAT analysis, they can be used in the process of clinical decision. In addition to the results of Brucella ELISA, reporting index values and determining optimal index values for each laboratory can help the diagnosis of brucellosis.

Frequency of azole resistance in clinical and environmental strains of Aspergillus fumigatus in Turkey: a multicentre study.

OBJECTIVES: Aspergillus fumigatus causes several diseases in humans and azole resistance in A. fumigatus strains is an important issue. The aim of this multicentre epidemiological study was to investigate the prevalence of azole resistance in clinical and environmental A. fumigatus isolates in Turkey. METHODS: Twenty-one centres participated in this study from 1 May 2018 to 1 October 2019. One participant from each centre was asked to collect environmental and clinical A. fumigatus isolates. Azole resistance was screened for using EUCAST agar screening methodology (EUCAST E.DEF 10.1) and was confirmed by the EUCAST E.DEF 9.3 reference microdilution method. Isolates with a phenotypic resistance pattern were sequenced for the cyp51A gene and microsatellite genotyping was used to determine the genetic relationships between the resistant strains. RESULTS: In total, resistance was found in 1.3% of the strains that were isolated from environmental samples and 3.3% of the strains that were isolated from clinical samples. Mutations in the cyp51A gene were detected in 9 (47.4%) of the 19 azole-resistant isolates, all of which were found to be TR34/L98H mutations. Microsatellite genotyping clearly differentiated the strains with the TR34/L98H mutation in the cyp51A gene from the strains with no mutation in this gene. CONCLUSIONS: The rate of observed azole resistance of A. fumigatus isolates was low in this study, but the fact that more than half of the examined strains had the wild-type cyp51A gene supports the idea that other mechanisms of resistance are gradually increasing.

The Emergence of Echinocandin-Resistant Candida glabrata Exhibiting High MICs and Related FKS Mutations in Turkey.

The frequency of invasive fungal infections shows a rising trend as well as a high morbidity and mortality. Among the causative agents, a shift toward the non-albicans Candida species including Candida glabrata species complex is being observed in several centers. Echinocandin resistance is increasingly published; however, isolates presenting with an in vitro resistance have not yet been reported from Turkey. We, herein, report the first FKS mutant and phenotypically echinocandin-resistant C. glabrata clinical strains from a single center in Turkey. In a 43-year-old female patient, several enterocutaneous fistulae developed after a long term hospitalization period and several complicated surgeries. She eventually required parenteral nutrition via a tunneled central venous catheter (CVC). Following a number of bacteremic and fungemic episodes as well as intensive antimicrobial interventions (including fluconazole, caspofungin and anidulafungin), a CVC-related candidemia caused by C. glabrata was detected. The isolated strain yielded high minimum inhibitory concentration (MIC) values for echinocandins and was categorized as resistant. A resistance-related mutation was detected in FKS2 HS1 (D666V). Blood cultures remained negative after the removal of the CVC and treatment with caspofungin and high-dose fluconazole. Following this first case, two additional C. glabrata strains with high echinocandin MICs were isolated from the urine cultures of two unrelated patients from different wards with different mutations in FKS2 HS1 (S663P and delF659). Our findings indicate that routine antifungal susceptibility testing is crucial and underlines the need for attention for the increasing trend of acquired echinocandin resistance in C. glabrata.

[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.

Clinical implications of fungal isolation from sputum in adult patients with cystic fibrosis

Background/aim: Cystic fibrosis is an autosomal recessive disease with a defect in mucociliary activity that is characterized by recurrent pulmonary infections. Bacterial agents frequently implicated in airway colonization are Haemophilus influenzae, Staphylococcus spp., and Pseudomonas spp. Fungal isolation from sputum is common in adults. However, growth of fungal agent only in sputum culture in patients with cystic fibrosis is insufficient for the diagnosis of fungal diseases. There is limited data about the clinical significance of fungal isolation in sputum cultures. The aim of the study was to investigate the clinical outcomes andsignificance of fungal isolation from sputum samples in adult CF. Materials and methods: This retrospective study included patients who have been admitted between October 2017 and January 2019 in an adult cystic fibrosis unit. Patients were grouped according to fungal pathogenicity as; fungal disease group, colonization group, and nonisolated group. The data of the last one year, including demographics, clinical data, laboratory, treatment modalities, results of cultured bacteria and fungus from sputum samples, respiratory function parameters, frequency of exacerbation, and hospitalizationwere compared between groups. Results: A total of 330 sputum samples from 88 adult patients with CF were collected. Patients were divided into 3 groups, the fungal disease group (n = 10, 11.4%), colonization group (n = 49, 55.7%), and nonisolated group (n = 29, 32.9%). Presence of pulmonary exacerbation, number of admissions to emergency department, and the number of positive cultures for bacteria from sputum were higher in the fungal disease group (p = 0.03, p = 0.01 and p < 0.001). The fungal disease group had higher rate of antibiotics by parenteral routethan other groups (p = 0.001) whereas lung functions were similar. Use of nutritional supplementation and parenteral antibiotherapy were the factors associated with elevated risk of fungal isolation. Conclusion: Frequent use of parenteral antibiotics and use of nutritional supplementation were found to be independent risk factors for fungal isolation from sputum in adult CF.

An Investigation into Bacterial Bloodstream Infections and Antibiotic Resistance Profiles in a Tertiary Hospital for a Ten-Year Period.

BACKGROUND: Bloodstream infections are one of the major causes of healthcare-associated morbidity and mortality. The present study aims to investigate the prevalence of the microorganisms isolated from blood cultures and to evaluate susceptibilities to antimicrobial agents in a tertiary center, Gulhane Training and Research Hospital, Ankara, Turkey. METHODS: Blood cultures (BCs) were incubated in BACTEC/9050 (Becton Dickinson, USA) (2007 - 2015) and BacT/ALERT (bio-Merieux, France) (2014 - 2016) automated systems. PhoenixTM 100 system (Becton Dickinson, USA) (2007 - 2014), MALDI-TOF MS (Bruker, USA) (2015 - 2016) and conventional techniques were used for the identification of isolated microorganisms. According to CLSI (2007 - 2014) and EUCAST (2015 - 2016) criteria, Kirby-Bauer disc diffusion method, PhoenixTM system, and broth microdilution were applied for antimicrobial susceptibility testing. Two five-year periods were statistically compared regarding antibiotic resistance. RESULTS: From the overall evaluated 31,380 BCs, 7,367 cultures (23.5%) were positive, excluding 503 BCs (6.4%), which were interpreted as contamination. Of 7,367 isolated microorganisms, 3,680 (50.0%) were gram-negative, 3,303 (44.8%) were gram-positive bacteria, and 384 (5.2%) were fungi. Coagulase-negative staphylococci (CoNS) were predominantly isolated (n = 2,075; 28.2%) among gram-positives. E.coli (n = 978; 13.3%) was the most frequently isolated gram-negative species. Between the first and the last five-year period, three genera (Enterococcus spp., Acinetobacter spp., Streptococcus spp.) showed significant differences when isolated, and only Enterococcus spp. showed increased isolation rates. In total, 90.3% of CoNS and 32% of S. aureus were methicillin-resistant. Only 75 strains of Enterococcus spp. (12.1%) were vancomycin-resistant. ESBL was detected in 40.6% of E. coli and 30.7% of Klebsiella spp. isolates. Carbapenem resistance showed a significant increase, particularly in K. pneumoniae (> 20%). CONCLUSIONS: The findings suggest that there was a threatening condition in antimicrobial resistance rates, especially for some antimicrobials between two periods. Although antimicrobial resistance is usually associated with MRSA, carbapenem resistance, ESBL, and VRE, the problem is far beyond these definitions, consisting of not just medicine, but also commercial companies, food industry, veterinarians, and other areas.

A new colorimetric method for rapid detection of ethambutol and streptomycin resistance in Mycobacterium tuberculosis: crystal violet decolorization assay (CVDA).

Streptomycin (STR) and ethambutol (EMB) are important drugs used for the treatment of tuberculosis. There is a need for fast, reliable and inexpensive methods for detecting resistance to these drugs. The aim of this study was to evaluate the performance of the crystal violet decolorization assay (CVDA) for the detection of STR and EMB resistance that is important drugs in tuberculosis treatment. In this study, drug susceptibility testing was performed on 140 Mycobacterium tuberculosis isolates provided from nine centers. Three tubes were used for each isolate. One of the tubes had a concentration of 2 mg/L STR and the other 5 mg/L EMB. The third was drug-free control tube. Sensitivity, specificity, positive predictive value (PPD), negative predictive value (NPD) and agreement for STR were found to be 81.8%, 94.6%, 87.8%, 91.5% and 90.57%, respectively. For EMB, sensitivity, specificity, PPD, NPD, and agreement were found to be 76%, 98.23%, 90.47%, 94.87% and 94.2%, respectively. The results were obtained in 11.3 ± 2.7 days (8-21 days). CVDA is rapid, reliable, inexpensive, and easy to perform for rapid detection of STR and EMB resistance, and it could be adapted for drug susceptibility testing.

Evaluation of a novel oxiconazole nitrate formulation: The thermosensitive gel.

Superficial fungal infections caused by Candida species are common skin diseases. Therefore, this study aimed to develop a new formulation containing oxiconazole nitrate, which is an azole group derivative for antifungal treatment, as a thermosensitive gel since there has been no literature study until now. MIC value of the novel thermosensitive formulation against three Candida species was calculated and time-dependent antifungal activity analysis was performed. Viscosity, transition temperature Tsol-gel (°C) and gelation time of the thermosensitive gel formulation were also determined in the viscometer. The measurements performed on the tensilometer device were analyzed for adhesion hardness and elongation percentages of the formulation. In the FT-IR spectrometer, the spectrum of solution and gel state was compared between 650 and 4000 cm-1 and it was found that there is no difference between them. It was found that the temperature is reversible on the formulation and did not cause any disruption of its components. Characterization parameters of the thermosensitive gel formulation containing oxiconazole nitrate and time-dependent activity against Candida species was observed to be the same as those of the solution containing only oxiconazole nitrate. MIC, MFC and time-dependent antifungal analysis did not show any particular difference between formulation and oxiconazole nitrate itself. Thermosensitive gel formulation containing oxiconazole nitrate was found to be effective on superficial fungal infections. We believe it is also appropriate for in vivo usage, but it is necessary to perform animal and human research. It is also needed to evaluate the formulation against other etiologic agents of superficial fungal infections.

Evaluation of the BACTEC MGIT 960 SL DST Kit and the GenoType MTBDRsl Test for Detecting Extensively Drug-resistant Tuberculosis Cases.

OBJECTIVE: The present study aimed to evaluate the performances of the BACTEC MGIT 960 SL DST kit and the GenoType MTBDRsl test for detecting second-line antituberculosis drug resistance in Multidrug-resistant TB (MDR-TB) cases. MATERIALS AND METHODS: Forty-six MDR-TB strains were studied. Second-line antituberculosis drug resistances were detected using the BACTEC MGIT 960 SL DST kit and the GenoType MTBDRsl test. The Middlebrook 7H10 agar proportion method was used as the reference test. RESULTS: The sensitivity and specificity values for the BACTEC MGIT 960 SL DST kit were both 100% for amikacin, kanamycin, capreomycin (4 µg/mL), and ofloxacin; 100% and 95.3%, respectively, for capreomycin (10 µg/mL); and 85.7% and 100%, respectively, for moxifloxacin (0.5 µg/mL). The sensitivity and specificity values for the GenoType MTBDRsl test to detect fluoroquinolone and aminoglycoside/cyclic peptide resistance were 88.9% and 100%, respectively, for ofloxacin and 85.7% and 94.9%, respectively, for moxifloxacin (0.5 µg/mL). The accuracy of the GenoType MTBDRsl assay for kanamycin, capreomycin, ofloxacin, and moxifloxacin was lower than that of the BACTEC MGIT 960 SL DST. CONCLUSION: The BACTEC MGIT 960 SL DST kit and the GenoType MTBDRsl were successful in detecting second-line antituberculosis drug resistance. Preliminary results of the GenoType MTBDRsl are very valuable for early treatment decisions, but we still recommend additional BACTEC MGIT 960 SL DST kit usage in the routine evaluation of drug-resistant tuberculosis.

Zika Virus-associated Ocular and Neurologic Disorders: The Emergence of New Evidence.

BACKGROUND: It has been approximately 70 years since the discovery of the Zika virus (ZIKV). It had been established that the virus causes mild infections and is confined to Africa and Asia; however, major changes in the clinical and epidemiologic patterns of ZIKV infection have occurred in recent years. The virus has attracted intense interest because of the possible association of several autoimmune and neurodevelopmental disorders. METHODS: We present a summary of the articles that attempt to explain the ZIKV unknowns and strengthen the association with some disorders that are thought to be related to ZIKV, by describing the discovery milestones from the initial identification of the virus to the present day. RESULTS: New evidence strengthens the association between ZIKV infections and Guillain-Barré syndrome (GBS), microcephaly and various neurodevelopmental and ophthalmologic disorders as a result of numerous new clinical and experimental studies. CONCLUSIONS: The World Health Organization declared the end of the "Public Health Emergency of International Concern" in December 2016, but ZIKV and associated consequences remain a significant enduring public health challenge.

Multicenter evaluation of crystal violet decolorization assay (CVDA) for rapid detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis.

The aim of this multicenter study was to evaluate the performance of the crystal violet decolorization assay (CVDA) for detection of multidrug resistant tuberculosis (MDR-TB). This study was performed in 11 centers in two phases. A total of 156 isolates were tested for INH and RIF resistance. In the phase I, 106 clinical isolates were tested in the Center 1-7. In the phase 2, 156 clinical isolates were tested in the center 1-6, center 8-11. Eighty six of 156 tested isolates were the same in phase I. Agreements were 96.2-96.8% for INH and 98.1-98.7% for RIF in the phase I-II, respectively. Mean time to obtain the results in the phase I was 14.3 ± 5.4 days. In the phase II, mean time to obtain the results was 11.6 ± 3.5 days. Test results were obtained within 14days for 62.3% (66/106) of isolates in the phase I and 81.4% (127/156) of isolates in the phase II. In conclusion, CVDA is rapid, reliable, inexpensive, and easy to perform for rapid detection of MDR-TB isolates. In addition, it could be adapted for drug susceptibility testing with all drugs both in developed and developing countries.

[Multicenter evaluation of the indirect nitrate reductase assay for the rapid detection of multidrug-resistant tuberculosis]. / Çok ilaca dirençli tüberkülozun hizli tespiti için dolayli nitrat redüktaz testinin çok merkezli degerlendirilmesi.

Multidrug-resistant tuberculosis (MDR-TB) is defined as resistance to at least isoniazid (INH) and rifampicin (RIF), and it complicates the implementation of tuberculosis control programmes. The rapid detection of MDR-TB is crucial to reduce the transmission of disease. The nitrate reductase assay (NRA) is one of the colorimetric susceptibility test methods for rapid detection of MDR-TB and based on the ability of reduction of nitrate to nitrite by Mycobacterium tuberculosis. The aim of this study was to evaluate the performance of the NRA for the rapid detection of MDR-TB. A total of 237 M.tuberculosis complex (MTC) isolates that were identified by the same method (BD MGIT(TM) TBc Identification Test, USA) from nine different medical centers in Turkey were included in the study. The susceptibility results of the isolates against INH and RIF obtained by reference test (Bactec MGIT(TM) 960, BD, USA) were then compared with NRA. In order to ensure consistency between centers, Löwenstein-Jensen (LJ) medium with antibiotics and without antibiotics (growth control) and Griess reagent solution were prepared in a single center (Ondokuz Mayis University School of Medicine, Medical Microbiology Department) and sent to all participant centers with the standardized test procedure. After the inoculation of bacteria into the test tubes, the tubes were incubated at 37°C, and after seven days of incubation, 500 µl Griess reagent was added to the LJ medium without antibiotics. If a color change was observed, an equal volume of Griess reagent was added to test LJ media with antibiotics. When a color change was observed in LJ media with antibiotics, it was considered that the isolate was resistant to tested antibiotics. Among 237 MTC isolates, 16 were resistant only to INH and nine were resistant only to RIF; 93 isolates (39.2%) were resistant (MDR) and 119 isolates (50.2%) were susceptible to both of the drugs determined with the reference susceptibility test. In the study, five INH-resistant isolates determined with reference method were found susceptible with NRT and eight INH-susceptible isolates determined with reference method were found resistant with NRT. In contrast, one RIF-resistant isolate determined with reference method was found susceptible with NRT and three RIF-susceptible determined isolates were found resistant with NRT. Accordingly, the concordance rate between the reference method and NRA were estimated as 94.5% for INH and 98.3% for RIF. The sensitivity, specificity, positive and negative predictive values of NRA were detected as 95.4%, 93.7%, 92.8% and 96% for INH, and 99%, 97.8%, 97.1% and 99.2% for RIF, respectively. The results of the 111 isolates were obtained on the seventh day, while the rest of the results were obtained between 10-14 days. In conclusion, the data of this multicenter study showed that NRA is a reliable, relatively inexpensive and practical method to perform for the rapid detection of MDR-TB.