[A New Method for Determination of Rifampicin and Isoniazid Resistance in Mycobacterium tuberculosis complex Isolates: Capillary Tube Method]. / Mycobacterium tuberculosis Kompleks Izolatlarinda Rifampisin ve Izoniyazid Direncinin Belirlenmesi için Yeni Bir Yöntem: Kapiller Tüp Yöntemi.

Tuberculosis continues to be an important public health problem worldwide. Culture methods are still considered the gold standard in the diagnosis of tuberculosis and the determination of drug resistance. The most important limitation of these methods is their long turnaround time. Commercial culture systems developed to shorten the duration are emerging as an economic problem, especially for developing countries. Therefore, cheap, fast, easy to apply and objectively evaluable tests are needed. In this study, in addition to culture-based methods for determining RIF and INH resistance in Mycobacterium tuberculosis complex isolates, it was aimed to develop the capillary tube method to accelerate the evaluation process. The study included 27 RIF-resistant, 36 RIF -sensitive, 30 INH-resistant, and 33 INH-sensitive isolates obtained from the mycobacteriology laboratory culture collection, for which susceptibility testing to firstline drugs were previously performed using the BACTEC MGIT 960 system (BD, USA) and were stored. H37Rv standard strain and an external quality control strain (IDT3) with known RIF and INH resistance were used as quality control isolates in the study. As a new testing method, the capillary tube method for detecting rifampicin and isoniazid resistance was compared to the standard BACTEC MGIT 960 system. In the determination of RIF and INH resistance, the sensitivity of the capillary tube method compared to the reference method was determined as 85% and 80%, respectively; however, the specificity values (25% and 45.5%, respectively) for both drugs were found to be low in the studies. The time to detect resistance with the capillary tube method varied between 4-9 days. Capillary tube method, which was developed especially for the rapid identification and treatment of multidrug-resistant isolates, is promising in that it detects resistant strains in a short time with a relatively high sensitivity, although its specificity is very low. It is thought that it would be beneficial to continue the study with a larger number of samples and even improve the method with studies conducted directly from clinical samples.

Endogenous Endophthalmitis Caused by Aspergillus lentulus in an Immunocompromised Patient with Lung Cancer

A 78-year-old man with a history of lung cancer, chemotherapy, radiotherapy, and coronavirus disease 2019 infection experienced visual deterioration of two-weeks' duration in his right eye. There was multifocal, yellowish-white retinitis foci, vascular engorgement, and scattered intraretinal hemorrhages extending from posterior pole to retinal periphery in the right eye, whereas the left eye was normal. Intravitreal vancomycin, ceftazidime, clindamycin, and dexamethasone were given for endogenous endophthalmitis initially. Vitreous culture confirmed the presence of Aspergillus lentulus, and he was treated with intravitreal amphotericin-B and voriconazole injections together with systemic amphotericin-B, voriconazole, posaconazole, and micafungin therapy. During follow-up, vitreoretinal surgery was performed because of rhegmatogenous retinal detachment, and he received one additional cycle of chemotherapy due to recurrence of the cancer. Although the retina was attached, enucleation was eventually required due to painful red eye. Atypical squamous cells beneath the neurosensory retina suggesting metastasis were noted on histopathological examination. Timely ocular examination is crucial for any immunocompromised patient having ocular symptoms. High level of suspicion for a fungal etiology is a must in these patients.

[Evaluation of Antimicrobial Susceptibilities of Rapidly Growing Mycobacteria]. / Hizli Üreyen Mikobakterilerin Antimikrobiyal Ilaçlara Duyarliliklarinin Belirlenmesi.

Infections related to the rapidly growing mycobacteria (RGM), which are common in the environment, have clinical significance as they can affect both immunocompromised and immunocompetent patients. Treatment of RGM related infections is difficult, because they are resistant to many of the first-line tuberculosis agents, require a long-term multiple drug regimen, which is costly, and is associated with drugrelated toxicities. The aim of this study was to investigate the in vitro antimicrobial susceptibility profiles of RGM isolated in Dokuz Eylül University Hospital and also to reveal epidemiological data. A total of 58 isolates [(Mycobacterium fortuitum (n= 35), Mycobacterium abscessus (n= 19) and Mycobacterium chelonae (n= 4)], which were isolated in Dokuz Eylül University Hospital between 2013 and 2018, were subjected to in vitro testing for nine antimicrobial agents (amikacin, cefoxitin, ciprofloxacin, clarithromycin, doxycycline, imipenem, linezolid, moxifloxacin and tobramycin) with the broth microdilution method recommended by the Clinical and Laboratory Standards Institute (CLSI). For M.abscessus; 73.68% of the isolates were found susceptible to amikacin; 73.68% of isolates were susceptible to clarithromycin at early reading and only 21.05% of them remained susceptible at late reading time. No resistance to imipenem were observed. M.abscessus isolates were highly resistant to tobramycin, doxycycline and fluoroquinolones. Antibiotic susceptibility testing of M.chelonae isolates demonstrated 100% susceptibility for amikacin, clarithromycin and tobramycin. No resistance to linezolid, imipenem and moxifloxacin were observed. None of the isolates were susceptible to cefoxitin. Ciprofloxacin and doxycycline also showed poor in vitro activity against M.chelonae isolates. For M.fortuitum clarithromycin susceptibility decreased from 32.35% to 2.94% after an additional incubation until 14 days. All tested isolates of the M.fortuitum were susceptible to amikacin, ciprofloxacin and moxifloxacin. None of the M.fortuitum isolates exhibited resistance to cefoxitin and imipenem. Most of the M.fortuitum isolates were resistant to tobramycin and doxycycline. When the results were evaluated together, RGM isolates in this study were highly susceptible to amikacin; and were highly resistant to doxycycline. In conclusion, this study supported that the status of antimicrobial susceptibilities were different between species and also showed the importance for hospitals to know susceptibility patterns of isolates in their region. It should be noted that accurate species determination is critical for treatment as well as susceptibility status of rapidly growing mycobacteria to the antimicrobials in use.

Comparison of polymerase chain reaction-restriction enzyme analysis method and DNA sequence analysis results in the identification of non-tuberculous mycobacteria.

The typing of non-tuberculous mycobacteria (NTM) is important from a clinical and epidemiological perspective. The polymerase chain reaction-restriction enzyme analysis (PRA) method and DNA sequence analysis method were utilized to target a gene region that codes the 65-kDa heat-shock protein for typing 150 suspected NTM samples isolated from the respiratory tract. Mycobacterium abscessus, Mycobacterium xenopi, Mycobacterium fortuitum, and Mycobacterium peregrinum were most frequently found by both methods. Six isolates that could not be defined by the PRA method were defined as Nocardia cyriacigeorgica, Nocardia abscessus, and Mycobacterium intracellulare by DNA sequence analysis. Discordance between the results of the two methods was observed for only one isolate. The isolate that was defined as Mycobacterium gordonae type 6 by the PRA method was defined as Mycobacterium senegalense by sequence analysis. The PRA method is simple and gives rapid results. Compared with DNA sequence analysis, it gives consistent and reliable results up to a ratio of 90%. DNA sequence analysis is the gold standard method in which all strains can be defined. However, given our laboratory conditions, its disadvantage is that it takes longer to reach a diagnosis than through the PRA method.

The role of molds in the relation between indoor environment and atopy in asthma patients.

BACKGROUND: The effect of mold fungi to allergic sensitization is not well-known. We aimed to evaluate the role of molds in the relation between indoor environment and atopy in asthmatics. MATERIALS AND METHODS: The air samples obtained from 66 stable asthmatics and 35 control subject's houses were sprayed into Sabouraud dextrose agar. Allergy skin testing were performed in both groups. The temperature and humidity of each house were measured. RESULTS: The incidence of atopy was similar in cases (59.1%) and controls (51.4%). The average amount of mold was 35.9 CFU/m(3) and 34.3 CFU/m(3), respectively. The number of household residents was positively correlated with the amount of molds. There was no difference in the amount of mold with respect to dosage of inhaler corticosteroids as well as symptom levels in asthmatics. The most frequently encountered allergens were Dermatophagoides farinae/Dermatophagoides pteronyssinus, grass/weeds and molds. Spending childhood in a village was more common among atopics. CONCLUSION: Living environment during the childhood might affect atopy and asthma. Based on the identification of molds as the second most frequent allergen after mites in our study population, assessment of mold sensitization as well as in forming patients about ways to avoid them seem likely to contribute to the effective management of uncontrolled asthma.