Invasive Mould Infections In Intensive Care Units: Epidemiology, Microbiologic Diagnosis And Antifungal Resistance

Invasive fungal infections present with a rising incidence and high morbidity and mortality rates. Among these infections are those due to moulds which draw particular attention per the diagnostic difficulties and higher mortality rates. While a relative decrease is observed in mortality rates regarding the use of prophylactic, empirical or preemptive antifungal regimens, there is a tendency of increase in antifungal resistance rates. Furthermore, due to increase in number of cases with immunosuppression, infections caused by rare and emerging moulds are now more frequently observed. Breakthrough infections, nosocomial infections, and infections due to risk factors other than immunosuppression are also a clinical concern. Diagnosis of invasive mould infections requires a multidisciplinary approach with clinical, radiological, histopathological and microbiological data. However, nonspecificity of clinical signs and radiological findings and difficulties in differentiation of infection and colonization are major problems in patients with invasive mould infections in intensive care units. Limited availability of routine microbiology laboratories with adequate facilities in mycological diagnostics and problems in specificity and sensitivity of diagnostic tests for intensive care unit patients result in further difficulties in diagnosis of these infections. In this review article, epidemiological data and microbiological diagnostic methods for invasive mould infections in intensive care units were reviewed per the published reports and the recommendations of current guidelines. Finally, antifungal resistance and clinical impact of resistance were discussed.WoSScopu

Zika virus infections in pregnancy: epidemics and case management

Zika virus is an RNA virus belonging to the Flaviviridae family, and is primarily transmitted by Aedes mosquitoes. Only a small number of cases had been described until 2007 when the first major Zika virus outbreak occurred on Yap Island, Micronesia. Approximately 80% of people infected with Zika virus do not exhibit any symptoms. Symptomatic infections are generally moderate and characterized by acute onset of fever, maculopapular rash, arthralgia, or conjunctivitis. The virus has recently attracted a broad interest due to the emerging cases of microcephaly that are possibly associated with mothers infected by the Zika virus during pregnancy, and the regional increases in the incidence of Guillain-Barre syndrome during the epidemic periods. Although the relationship between Zika virus infection and these abnormalities is not obviously understood yet, Zika virus testing is recommended for infants with microcephaly or intracranial calcifications whose mothers were potentially infected with the Zika virus during pregnancy. Every day, new reports are being published about the outbreaks associated with this virus; nevertheless, no new cases of this virus have been reported in Turkey. Despite this, we cannot currently exclude the possibility of the encounter with the virus because of the presence of Aedes mosquitoes, which are responsible for the spread of the virus, are prevalent in Turkey, and an increasing number of travel-related cases are being reported from different countries. In the light of the current knowledge on this virus, this review aims to discuss the course of Zika virus infections in detail, especially congenital infection, and presenting current information about the case management and preventive measures. [Cukurova Med J 2016; 41(1.000): 143-151

Arising Prevalence Of Oxa-48 Producer Escherichia Coli And Oxa-48 With Ndm Co-Producer Klebsiella Pneumoniae Strains

Background/aim: This prospective study aimed to determine the presence of the most common carbapenemase genes, blaOXA-48, blaKPC, blaIMP, blaVIM and blaNDM on carbapenem resistant clinical K.pneumoniae and E.coli isolates. Materials and methods: Isolates were selected according to EUCAST guideline; gradient test and disc diffusion with both meropenem and ertapenem discs. Resistance rates of these isolates to other antimicrobial agents were also examined by disc diffusion method. Carbapenem resistance gene were investigated by using Real-Time PCR. Results: A total of 3845 E. coli and 1689 K. pneumoniae isolates from clinical samples between January 2015 and April 2017 were evaluated. The 419 isolates were found as carbapenem resistant but only the first resistant isolate (n=155; 126 K. pneumoniae and 29 E.coli) of each patient were included. Carbapenem resistant isolates were most frequently isolated from intensive care units (48.8%). Colistin was the most effective antibiotic (91.0%). The 121 (78.1%) of the tested isolates were positive for OXA-48 (103 K. pneumoniae and 18 E. coli) and 9 K. pneumoniae carrying blaNDM were also positive for blaOXA-48. VIM, IMP and KPC type carbapenemases were not detected in any isolates. Conclusion: Carbapenem-resistant pathogens have been shown to be able to develop resistance mechanisms with more than one carbapenemase encoding gene.Wo

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. Keywords: Oxiconazole nitrate, Thermosensitive gels, Poloxamer 407, Candida, Antifungal activit

Multicenter Evaluation Of The Indirect Nitrate Reductase Assay For The Rapid Detection Of Multidrug-Resistant Tuberculosis

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, Lowenstein-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 degrees C, and after seven days of incubation, 500 mu l 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.WoSScopu

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 2mg/L STR and the other 5mg/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 +/- 2.7days (8-21days). 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

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

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