scholarly journals A Current Microbiological Picture of Mycobacterium Isolates from Istanbul, Turkey

2020 ◽  
Vol 69 (2) ◽  
pp. 185-191
Author(s):  
BILGE SUMBUL ◽  
MEHMET ZIYA DOYMAZ

Despite advances in diagnosis and treatment, tuberculosis (TB) continues to be one of the essential health problems throughout the world. Turkey is considered to be endemic for TB. In this study, we analyzed the distribution of Mycobacterium species, compare the diagnostic methods, and susceptibilities to anti-tuberculosis drugs of TB isolates. The aim was to document the current status and to provide a frame of reference for future studies. In this study, 278 Mycobacterium species isolated from 7,480 patients between September 2015 and June 2019 were included. Löwenstein-Jensen medium (LJ) and MGIT 960 were used for the isolation of strains. Susceptibility to 1st-line anti-tuberculosis drugs was determined. Positivity rates in clinical samples were as follows: 1.4% for direct microscopic acid-fast bacilli (AFB) detection, 3.4% for growth on the LJ, and 3.7% for growth on MGIT-960. Two hundred thirty-three isolates were identified as Mycobacterium tuberculosis complex (MTBC) and 45 were non-tuberculous mycobacteria (NTMs). Eleven of the NTMs (24.4%) were Mycobacterium fortuitum group isolates, and eight NTMs (17.7%) were Mycobacterium abscessus complex isolates. A number of patients diagnosed with tuberculosis peaked twice between the ages of 20–31 and 60–71. A hundred and eighty-two MTBC isolates (78.1%) were susceptible to all 1st-line anti-tuberculosis drugs, while 51 isolates (21.9%) were resistant to at least one drug tested. The multidrug-resistant tuberculosis rate was 13.7% among resistant strains and 3% in all strains. The liquid cultures were better for detection of both MTBC and NTMs isolates. The data demonstrate that MTBC continues to be challenge for this country and indicates the need for continued surveillance and full-spectrum services of mycobacteriology laboratory and infectious diseases.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marta Fernández-Martínez ◽  
Claudia González-Rico ◽  
Mónica Gozalo-Margüello ◽  
Francesc Marco ◽  
Irene Gracia-Ahufinger ◽  
...  

AbstractThe objective of this study was to analyse the mechanisms of resistance to carbapenems and other extended-spectrum-β-lactams and to determine the genetic relatedness of multidrug-resistant Enterobacterales (MDR-E) causing colonization or infection in solid-organ transplantation (SOT) recipients. Prospective cohort study in kidney (n = 142), liver (n = 98) or kidney/pancreas (n = 7) transplant recipients between 2014 and 2018 in seven Spanish hospitals. We included 531 MDR-E isolates from rectal swabs obtained before transplantation and weekly for 4–6 weeks after the procedure and 10 MDR-E from clinical samples related to an infection. Overall, 46.2% Escherichia coli, 35.3% Klebsiella pneumoniae, 6.5% Enterobacter cloacae, 6.3% Citrobacter freundii and 5.7% other species were isolated. The number of patients with MDR-E colonization post-transplantation (176; 71.3%) was 2.5-fold the number of patients colonized pre-transplantation (71; 28.7%). Extended-spectrum β-lactamases (ESBLs) and carbapenemases were detected in 78.0% and 21.1% of MDR-E isolates respectively. In nine of the 247 (3.6%) transplant patients, the microorganism causing an infection was the same strain previously cultured from surveillance rectal swabs. In our study we have observed a low rate of MDR-E infection in colonized patients 4–6 weeks post-transplantation. E. coli producing blaCTX-M-G1 and K. pneumoniae harbouring blaOXA-48 alone or with blaCTX-M-G1 were the most prevalent MDR-E colonization strains in SOT recipients.


2020 ◽  
Vol 12 (03) ◽  
pp. 203-211
Author(s):  
Megha Sharma ◽  
Bharti Malhotra ◽  
Jitendra Tiwari ◽  
Shipra Bhargava

Abstract Objective Infections due to nontuberculous mycobacteria (NTM) is increasing globally and may present as drug-resistant tuberculosis (DRTB). In India, data on NTM prevalence and species diversity is limited. Present study was conducted to detect the prevalence and profile of NTM among patients suspected of DRTB using paraffin slide culture (PSC)and mycobacteria growth indicator tube (MGIT) culture methods for isolation of NTM. Material and Method A total of 2,938 samples suspected of TB/DRTB were cultured on PSC and MGIT960. Species identification of mycobacterial isolate was done by sequencing of 16s ribosomal RNA gene. Result Among 2938 samples, 35 (1.19%) were found positive for NTM by PSC and 9 (0.30%) were found positive by MGIT. The diversity of NTM species was high (13 species). Out of 35 NTM isolates by PSC, maximum 34.29% (12) isolates were found to be Mycobacterium fortuitum, followed by 11.43% (4) Mycobacterium abscessus and Mycobacterium chelonae, and 42.85% (15) were other species viz. 8.57% (3) were Mycobacterium intracellulare and Mycobacterium kansasii, 5.71% (2) were Mycobacterium peregrinum, and 2.85% (1) were Mycobacterium flavescens, Mycobacterium farcinogenes, Mycobacterium moriokanese, Mycobacterium wolinskyi, Mycobacterium simiae, Mycobacterium goodii, and Mycobacterium terrae each. Coinfection of Mycobacterium tuberculosis(MTB) and NTM was found in 60% (21) samples. Conclusion Prevalence of NTM was low among multidrug resistant tuberculosis/TB suspected patients, similar to other studies done in India. PSC was found better than MGIT for the isolation of NTM, though poor separation of NTM and MTB on subculture may have led to false negativity in cases of coinfection. About 13 species were isolated; M. fortuitum was the most common of all. Since coinfection of NTM and TB can also occur, samples of patients suspected of NTM should be cultured on PSC even if positive for MTB.


Author(s):  
Tkachev A.V. ◽  
Baturin V.A.

A comparative study of resistance to anti-tuberculosis drugs in patients with newly diagnosed pulmonary tuberculosis and in patients with chronic forms of tuberculosis who were treated in an anti-tuberculosis hospital was carried out. We examined 142 patients treated in the department of resistant forms of tuberculosis. A complete bacteriological study of sputum for Mycobacterium tuberculosis was carried out with the determination of sensitivity to anti-tuberculosis drugs during the cultivation of microorganisms on a liquid nutrient medium in a system with automated registration of bacterial growth and on a dense nutrient medium of Lowenstein-Jensen using the method of absolute concentrations. Methods of PCR analysis were also used. According to the anamnesis, two groups of patients were formed: 82 patients with newly diagnosed tuberculosis and 60 patients with a chronic course of the disease or with a relapse of the disease. According to the age structure, patients under the age of 50 prevailed in both groups. At the same time, in the first group there was a significant number of patients aged 18-29 years - 20.7%. In the second group, the number of patients aged 18-29 years was significantly less - 5%. Despite the fact that all patients were assigned to the category of multidrug-resistant pathogen and were treated in the unit of resistant forms of tuberculosis, it was important to assess the level of Mycobacterium tuberculosis resistance separately for patients in each of the selected groups. The largest differences between groups were found in the assessment of second-line drug resistance. Patients of the second group showed high resistance to fluoroquinolones - 30% and amikacin - 41.6%. In patients with newly diagnosed pulmonary tuberculosis (first group), resistance to fluoroquinolones was 9.7%, and to amikacin - 17.1%. Capreomycin was the most effective in both groups. The resistance of the causative agent of tuberculosis in patients of the first group was 4.9%, in the second - 11.6%.


2021 ◽  
Vol 22 (2) ◽  
pp. 304-309
Author(s):  
T. Ouassa ◽  
M.S. N’Guessan-Kacou ◽  
K.A. Kouakou

Background: Apart from tuberculosis caused by Mycobacterium tuberculosis complex (MTBc) species, there are many other  mycobacterial infections due to nontuberculous mycobacteria (NTM). These are rarely identified in many low resource settings in Africa because of the lack of accurate identification methods. The aim of the study is to identify NTM species involved in respiratory infections in Abidjan, Ivory Coast.Methodology: Isolates routinely identified as NTM by the detection of MPT64 antigen between 2015 and 2018 at the Centre for Diagnosis and Research on AIDS and other Infectious Diseases (CeDReS) of the University Hospital of Treichville, were included in the study. Bacterial strains were sub-cultured on three different Lowenstein-Jensen media in order to determine their cultural characteristics, and molecular identification of the strains was performed first by polymerase chain reaction (PCR) assay followed by reverse hybridization (GenoType Mycobacterium CM and AS kits, Hain Lifescience, Germany). The Cohen’s kappa statistical coefficientwas used to evaluate the degree of agreement of the phenotypic with the molecular method.Results: Of 62 NTM isolates tested with the molecular method, 54 (87.1%) tested positive and the main species identified were Mycobacterium fortuitum (52%), followed by Mycobacterium abscessus (13%) alone or in combination with other species. Thirty-six (58.1%) of the 62 NTM isolates were identified phenotypically, out of which 31 (86.1%) were correctly identified by molecular method. The comparison of molecular and phenotypic methods revealed a good concordance, allowing the use of cultural patterns as identification tests in resource limited settings. However, MTBc isolates were identified among the NTM isolates, indicating that even if the rapid test for detection of MPT64 antigen is quite accurate, it could lack sensitivity and specificity in some cases.Conclusion: Mycobacterium fortuitum and M. abscessus were identified as the main NTM species circulating in Abidjan but there is need for additional evaluation of MPT64 antigen detection assay for MTBc. Keywords: non-tuberculous mycobacteria, identification, PCR, GenoType CM/AS, culture   French Title: Mycobactéries non tuberculeuses isolées chez des patients suspects de tuberculose à Abidjan, Côte d'Ivoire Contexte: Outre la tuberculose causée par les espèces du complexe Mycobacterium tuberculosis (MTBc), il existe de nombreuses autres infections mycobactériennes dues à des mycobactéries non tuberculeuses (MNT). Ceux-ci sont rarement identifiés dans de nombreuses régions à ressources limitées, notamment en Afrique en raison du manque de méthodes d'identification précises. Le but de l'étude était d'identifier les espèces de MNT impliquées dans les infections respiratoires à Abidjan, en Côte d'Ivoire.Méthodologie: Des isolats identifiés en routine comme étant des MNT par la détection de l'antigène MPT64 entre  Non-tuberculous mycobacteria in Ivory Coast  2015 et 2018 au Centre de diagnostic et de recherche sur le sida et autres maladies infectieuses (CeDReS) sis au sein du CHU de Treichville, ont été inclus dans l'étude. Les souches bactériennes ont été réisolées sur trois milieux de Lowenstein-Jensen différents afin de déterminer leurs caractéristiques culturales, et l'identification moléculaire des souches a d'abord été réalisée par un test réaction de polymérisation en chaîne (PCR) suivi d'une hybridation inverse (kits GenoType Mycobacterium CM et AS, Hain Lifescience, Allemagne). Le test statistique kappa de Cohen a été utilisé pour évaluer le degré d’accord entre le phénotype et la méthode moléculaire.Résultats: Sur 62 isolats de NTM testés avec la méthode moléculaire, 54 (87,1%) ont été trouvés positifs les principales espèces identifiées étant Mycobacterium fortuitum (52%), suivi de Mycobacterium abscessus (13%) seul ou en association avec d'autres espèces. Trente-six (58,1%) des 62 isolats de MNT ont été identifiés phénotypiquement, parmi lesquels 31 (86,1%) ont été correctement identifiés par la méthode moléculaire. La comparaison des méthodes moléculaires et phénotypiques a révélé une bonne concordance, permettant l'utilisation de caractères culturaux comme tests d'orientation dans des zones à ressources limitées. Cependant, des isolats de MTBc ont été identifiés parmi les isolats de MNT, indiquant que même si le test rapide de détection de l'antigène MPT64 est assez précis, il pourrait manquer de sensibilité et de spécificité dans certains cas. Conclusion: Mycobacterium fortuitum et M. abscessus ont été identifiés comme les principales espèces de MNT circulant à Abidjan mais il est nécessaire de procéder à une évaluation supplémentaire du test de détection de l'antigène MPT64 pour l'identification des MTBc. Mots clés: mycobactéries non tuberculeuses, identification, PCR, GenoType CM/AS, culture


2021 ◽  
Vol 12 ◽  
Author(s):  
Qiong Ma ◽  
Rende Chen ◽  
Enhui Yang ◽  
Youhua Yuan ◽  
Yongfu Tian ◽  
...  

Non-tuberculous mycobacterial (NTM) infection of the musculoskeletal system is rare but poses a grave threat to public health. These infections yield non-specific symptoms that remain undetected until the development of the later stages of the disease. In this study, we performed a retrospective review of 25 cases of musculoskeletal NTM infection at two tertiary medical centres over a 5-year period to determine the clinical features and improve the current clinical diagnosis and treatment. The most common mycobacterial species detected were Mycobacterium fortuitum in eleven patients, Mycobacterium abscessus in eight patients, Mycobacterium houstonense in three patients, Mycobacterium avium in two patients, and Mycobacterium smegmatis in one patient. The sites of infection included the limbs and joints, most commonly the knee (ten patients) and foot (six patients). The median duration from the onset of symptoms to diagnosis was 2.5 months (0.8–13.5 months). Deep sinus tracts extending to the surgical site were observed in 60% of the patients (15/25), and granulomatous inflammation and granulomatous inflammation with necrosis occurred in 60% of the patients (15/25). All patients underwent surgical treatment for infection control, and all patients, except one, received antimycobacterial therapy based on drug sensitivity assays. The median duration of the antimicrobial chemotherapy was 5 months (range: 3–20 months). At the final follow-up, 24 patients presented with absence of recurrence and one patient succumbed owing to heart failure after debridement. Our findings highlight the importance of vigilance and improvements in the diagnostic methods for musculoskeletal NTM infection. Aggressive surgical treatment and antimycobacterial drug treatment can help achieve satisfactory results.


Author(s):  
Yuting Luo ◽  
Yafeng Xie ◽  
Yongjian Xiao

With the increasing number of patients infected with syphilis in the past 20 years, early diagnosis and early treatment are essential to decline syphilis prevalence. Owing to its diverse manifestations, which may occur in other infections, the disease often makes clinicians confused. Therefore, a sensitive method for detecting T. pallidum is fundamental for the prompt diagnosis of syphilis. Morphological observation, immunohistochemical assay, rabbit infectivity test, serologic tests, and nucleic acid amplification assays have been applied to the diagnosis of syphilis. Morphological observation, including dark-field microscopy, silver-staining, and direct fluorescent antibody staining for T. pallidum, can be used as a direct detection method for chancre specimens in primary syphilis. Immunohistochemistry is a highly sensitive and specific assay, especially in the lesion biopsies from secondary syphilis. Rabbit infectivity test is considered as a sensitive and reliable method for detecting T. pallidum in clinical samples and used as a historical standard for the diagnosis of syphilis. Serologic tests for syphilis are widely adopted using non-treponemal or treponemal tests by either the traditional or reverse algorithm and remain the gold standard in the diagnosis of syphilis patients. In addition, nucleic acid amplification assay is capable of detecting T. pallidum DNA in the samples from patients with syphilis. Notably, PCR is probably a promising method but remains to be further improved. All of the methods mentioned above play important roles in various stages of syphilis. This review aims to provide a summary of the performance characteristics of detection methods for syphilis.


2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Seifu Gizaw Feysia ◽  
Malihe Hasan-nejad ◽  
Siroos Amini ◽  
Gholamreza Hamzelou ◽  
Hossein Kazemian ◽  
...  

BACKGROUND: Nontuberculous mycobacterial (NTM) infections have radically increased worldwide due to the increase in HIV infections. The disease activity increases with progressive immunodeficiency.METHODS: A total of 216 HIV seropositive patients suspected of having mycobacterial infection were recruited for this study. Clinical samples were collected from each patient and cultured on Lowenstein-Jensen media. Detection and species identification were simultaneously done using Reverse Blot Hybridization Assay System. Also, the minimum inhibitory concentrations (MIC) for each isolate were determined in 7H9 broth media for 10 antibiotics.RESULTS: In this study, 4 rapid and 4 slow-growing NTM species were isolated and identified. Mycobacterium fortuitum was the most common NTM species, 3/8 (37.5%), followed by Mycobacterium kansasii, 2/8 (25%). The cases were identified as pulmonary disease, 5/8 (62.5 %), disseminated infection, 2/8 (25%), and skin abscess, 1/8 (12.5%). M. chelonae and Mycobacterium avium were isolated from patients diagnosed with disseminated infection with treatment failure. The skin abscess was caused by infection with M. simiae. The results of the MIC testing were as follows: M. kansasii and M. fortuitum were susceptible to amikacin (AMK); M. avium to clarithromycin (CLA); M. fortuitum 2/3 (67%) to ciprofloxacin (CIP); 1/2 (50%) of M. kansasii isolates to CLA, and M.chelonae to rifampin (RIF), linezolid (LIN), AMK, and CIP atmedium and high concentrations.CONCLUSION: AMK showed incredible in vitro activity against M. kansasii and M. fortuitum. Also, M. avium was susceptible to CLA, whereas M. simiae and M. chelonae were resistant to the tested drugs in this study. 


2020 ◽  
pp. 54-59
Author(s):  
A. S. Molostova ◽  
N. S. Gladyshev ◽  
A. V. Svarval ◽  
R. S. Ferman ◽  
A. B. Karasyova ◽  
...  

(HP) infection was performed using invasive and non-invasive methods. The study group consisted of 95 patients with dyspepsia. HP infection was detected in 47 patients (49.4 %). The expediency of using a set of diagnostic methods for detecting HP (PCR, immunochromatographic, bacteriological and method for determining urease activity) is proved. Most often (100 %) in patients HP infection was detected in biopsies using the PCR method. Somewhat less frequently it was detected when examining biopsies with an invasive biochemical method (AMA RUT Reader) (82 %) and fecal immunochromatographic method (83 %). Despite the fact that helicobacteriosis was detected bacteriologically in a small number of patients (24 %), this method is of particular value, since it allows you to assess the sensitivity to antimicrobial drugs and probiotics, and does not give false positive results.


2019 ◽  
Vol 20 (1_suppl) ◽  
pp. 38-44
Author(s):  
Mizuya Fukasawa

At the second Dialysis Access Symposium held in Nagoya, Japan, a proposal was made to investigate the differences in vascular access methods used in different countries. In this article, we describe the management of vascular access in Japan. The Japanese population is rapidly aging, and the proportion of elderly patients on dialysis is also increasing. There were 325,000 dialysis patients in Japan at the end of 2015, of whom 65.1% were aged 65 years or above. The number of patients with diabetic nephropathy or nephrosclerosis as the underlying condition is also increasing, whereas the number with chronic glomerulonephritis is steadily decreasing. The Japanese health insurance system enables patients to undergo medical treatment at almost no out-of-pocket cost. Percutaneous transluminal angioplasty suffers from a severe device lag compared with other countries, but although there are limitations on permitted devices, the use of those that have been authorized is covered by medical insurance. One important point that is unique to Japan is that vascular access is performed and managed by doctors involved in dialysis across a wide range of disciplines, including nephrologists, surgeons, and urologists. This may be one factor contributing to the good survival prognosis of Japanese dialysis patients.


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