scholarly journals Molecular identification and antibiotic resistance pattern of actinomycetes isolates among immunocompromised patients in Iran, emerging of new infections

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hossein Ali Rahdar ◽  
Shahram Mahmoudi ◽  
Abbas Bahador ◽  
Fereshteh Ghiasvand ◽  
Fatemah Sadeghpour Heravi ◽  
...  

AbstractRecent advancements in DNA-based approaches have led to the identification of uncommon and rare bacterial pathogens. In this study, by utilizing a DNA-based approach, a total of 1043 clinical specimens were processed for the identification of actinobacteria targeting the 16S rRNA and gyrB genes. Drug susceptibility testing was also conducted using micro-broth dilution and PCR. Two isolates of Nocardia flavorosea and Rhodococcus erythropolis were reported for the first time in Iran. Also, Nocardiopsis dassonvillei, Streptomyces olivaceus, and Streptomyces griseus were reported for the first time in Asia. Infections caused by Nocardia caishijiensis and Prauserella muralis have also been reported in this study. The first Asian case of pulmonary infection caused by Nocardia ignorata and the first global case of brain abscess caused by Nocardia ninae and Nocardia neocaledoniensis have been reported in this study. Overall 30 isolates belonging to 6 genera (Nocardia, Streptomyces, Rodoccoccus, Nocardiopsis, Rothia, and Prauserella) were detected in 30 patients. All 30 isolates were susceptible to amikacin and linezolid. Three isolates including Nocardia otitidiscaviarum (n = 2) and Nocardia flavorosea (n = 1) were resistant to trimethoprim-sulfamethoxazole which were the first trimethoprim-sulfamethoxazole resistant clinical actinomycetes in Iran. Isolation of rare species of actinomycetes particularly Nocardia spp. requires urgent action before they spread clinically particularly among immunocompromised patients.

1970 ◽  
Vol 10 (2) ◽  
pp. 45-47 ◽  
Author(s):  
Mostafizur Rahman ◽  
SM Mostafa Kamal ◽  
Fazle Rabbi Mohammed ◽  
Md Billal Alam ◽  
HAM Nazmul Ahasan

Background: Anti-Tuberculosis (TB) drug resistance is emerging as a new global health problem. No national data on drug resistance is available in Bangladesh. The absolute number of multidrug resistant TB (MDR-TB) is expected to be high considering high TB burden. This study was aimed to determine the resistance pattern of mycobacterium tuberculosis (MTB) isolates among different category of patient. Method: A total 1123 randomly selected patients having clinical and or radiological features of tuberculosis attending out patients department of NIDCH were enrolled in this study during January to December, 2008. Sputum were collected and processed for culture by digestion, decontamination and concentration following modified Petroff's method and were inoculated on to two slopes of Lowenstein- Jensen (L-J) media for six weeks. The identity of the isolates was made by growth rate, colony morphology, P-nitrobenzoic acid (PNB) susceptibility, catalase and nitrate reduction tests. Ultimately drug susceptibility testing (DST) were performed. Result: Drug susceptibility testing for Isoniazid (INH), Rifampicin (RIF), Ethambutol (EMB) and Streptomycin (SM) was done among 363 cases. Resistance rates for INH, RIF, EMB and SM were 76.03%, 71.63%, 27.55% and 55.65% respectively. According to DST report, total 221 cases were detected as multi drug resistant TB (MDR-TB). Among them, 87% cases were MDR-TB in category II (CAT - II) failure and 13% were MDR-TB in category I (CAT - I) failure and it was 0% in new cases. Conclusion: Pattern of anti TB drug resistance was identified in this study. More surveillance and immediate therapeutic interventions should be performed in order to combat the threat of MDR-TB to the general population. Keywords: Tuberculosis, Multi drug resistance, Drug susceptibility testing.   doi: 10.3329/jom.v10i2.2812 J MEDICINE 2009; 10 : 45-47


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Moges Tiruneh ◽  
Sisay Yifru ◽  
Mucheye Gizachew ◽  
Kassie Molla ◽  
Yeshambel Belyhun ◽  
...  

Background. In most hospitals of developing countries, urinary tract infections are treated empirically because of lack of culture facilities. This leads to emergence of multiresistant uropathogens. Culturing and drug susceptibility testing are essential to guide therapy. Objectives. To assess changing prevalence and resistance pattern of uropathogens to commonly used antibiotics in a two-year study period. Methods. Urine specimens were collected and cultured. Uropathogens were identified by standard methods and tested for antibiotics resistance. Data were analyzed using SPSS version 16 statistical sofware. P value < 0.05 was considered statistically significant. Results. The commonest isolates in both the previous and present studies were E. coli, Klebsiella, CoNS, S. aureus, Proteus, and Citrobacter species. Previous isolates of Enterobacteriaceae were 100% sensitive to ciprofloxacin, whereas present isolates developed 31% to 60% resistance to it. Previous isolates were less resistant to gentamycin than the present ones. Multiresistance isolates were predominant in present study than previous ones. Conclusion. E. coli was predominant in the two study periods. Present isolates were more resistant than previous ones. Some previous isolates were 100% sensitive to ciprofloxacin, whereas present isolates were increasingly resistant. Ciprofloxacin and gentamicin have been recommended for empiric treatment of urinary tract infections.


2020 ◽  
Vol 17 (2) ◽  
pp. 0444
Author(s):  
Fairuz Tawgozy et al.

Mycobacterium tuberculosis resistance to rifampicin is mainly mediated through mutations in the rpoB gene. The effects of rpoB mutations are relieved by secondary mutations in rpoA or rpoC genes. This study aims to identify mutations in rpoB, rpoA, and rpoC genes of Mycobacterium tuberculosis isolates and clarify their contribution to rifampicin resistance. Seventy isolates were identified by acid-fast bacilli smear, Genexpert assay, and growth on Lowenstein Jensen medium. Drug susceptibility, testing was performed by the proportional method.  DNA extraction, PCR, and sequencing were accomplished for the entire rpoA, rpoB, and rpoC genes. Twenty-three isolates (32.85%) showed resistance to rifampicin by either proportion method or Genexpert assay. Sequence analysis of the rpoB gene revealed fourteen different mutation patterns. Inside the rifampicin resistance determining region (RRDR), codons: S531L, D516V were highly mutated with frequencies of (21.73%, 17.39%) respectively. Outside the RRDR, there were nine different types of mutations, and M479L was the most prevalent one. Out of 23 RIF resistant isolates, seven isolates (30.43%) carried mutations in the rpoA gene, and twelve isolates (52.17%) harbored a mutation in rpoC. Most of the mutations were identified for the first time in this study. The current study demonstrated that mutations in rpoB, rpoA, and rpoC contributed to RIF resistance in Mycobacterium tuberculosis and this new finding may be relevant to realize how compensatory mutations in the rpoA and rpoC genes restore the fitness cost caused by rifampin resistance-conferring mutations in rpoB.


2014 ◽  
Vol 58 (9) ◽  
pp. 5632-5635 ◽  
Author(s):  
Zhijian Zhang ◽  
Yufeng Wang ◽  
Yu Pang ◽  
Changting Liu

ABSTRACTWe compared the efficiencies of different drug susceptibility testing methods in detecting rifampin (RIF) heteroresistance inMycobacterium tuberculosis. Our data revealed that the broth dilution method found more resistance than MGIT did (P= 0.046) for the low-resistance group. Similarly, the broth dilution method was more sensitive in detecting RIF heteroresistance in subpopulations with low growth rates than was MGIT (P= 0.033). In conclusion, our data demonstrated that the broth dilution method was more sensitive than MGIT in detecting RIF heteroresistance.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ariadna Rando-Segura ◽  
María Luisa Aznar ◽  
María Milagros Moreno ◽  
Mateu Espasa Soley ◽  
Elena Sulleiro Igual ◽  
...  

Abstract Background The importance of Mycobacterium tuberculosis strains with disputed rpoB mutations remains to be defined. This study aimed to assess the frequency and types of rpoB mutations in M. tuberculosis isolates from Cubal, Angola, a country with a high incidence of tuberculosis. Methods All isolates included (n = 308) were analyzed using phenotypic drug susceptibility testing and GenoType MTBDRplus assay. DNA sequencing of the rpoB gene and determination of rifampicin MIC by macrodilution method were additionally performed on isolates yielding discordant results (n = 12) and those in which the mutation detected was not characterized (n = 8). Results In total, 85.1% (74/87) of rifampicin-resistant strains had undisputed rpoB mutations -S450L (49), D435V (15), H445D (3), H445Y (2), Q432ins (1), L449M plus S450F (1), S450F (1), S450W (1) and S450Y (1)-; 10.3% (9/87) had disputed rpoB mutations—L430P plus S493L (1), N437del (1), H445L (3), D435Y (2), L452P (2)-, 2.3% (2.3%) showed no rpoB mutations and 2.3% (2/87) showed heteroresistance—D435Y plus L452P and L430P plus S493L-. Conclusion Disputed rpoB mutations were common, occurring in 10.3% of rifampicin resistant isolates. Current phenotyping techniques may be unable to detect this resistance pattern. To increase their sensitivity, a lower concentration of RIF could be used in these tests or alternatively, rpoB mutations could be screened and characterized in all M. tuberculosis strains.


2016 ◽  
Vol 5 (01) ◽  
pp. 4715
Author(s):  
A. V. Sowmya* ◽  
G. Jayalakshmi ◽  
David Agatha

Pneumonia is a common illness accounting for majority of hospitalizations worldwide with significant mortality and morbidity. Antimicrobial therapy, being the main stay of treatment, the choices of antibiotics depends on the nature of the etiologic agents and the host factors. The current study was aimed to identify the bacterial & fungal etiologic agents of Community Acquired Pneumonia (CAP) in Immunocompromised (IC) patients, with their antimicrobial resistant pattern and to analyze the associated immunocompromised states. Various respiratory samples from study group of 75 immunocompromised patients with features of pneumonia were collected, processed and the isolates were identified with their antimicrobial susceptibility& resistance pattern according to CLSI guidelines. The results were analyzed statistically. Diabetes mellitus is the most common immunocompromised state (48%) associated with CAP. Monomicrobial and polymicrobial infection rates were 80.36% and 19.64% respectively. Gram negative pathogens and fungal pathogens were identified in 60% and 25.37% of culture positive cases respectively. Diabetes mellitus is commonly found in association with polymicrobial infection (19.44%) and fungal infection (16.66%). Drug resistant strains comprise about 75% of MRSA strains, 72.72 % of ESBL producers and 3.44% of Amp C producers. As the number of elderly people with associated IC state is on rise, with change in the pattern of microbial etiologic agents causing CAP, a prior knowledge of the host and microbial factors will help in formulating empirical antimicrobial therapy and proper treatment thereby curbing the spread of infections by drug resistant pathogens and the associated morbidity and mortality.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 797
Author(s):  
Vichita Ok ◽  
Alexandra Aubry ◽  
Florence Morel ◽  
Isabelle Bonnet ◽  
Jérôme Robert ◽  
...  

The MDR/MTB ELITe MGB® kit (ELITech) carried on the ELITe InGenius® platform is a new real-time PCR assay allowing automated extraction and detection of DNA of the Mycobacterium tuberculosis complex (MTB) and mutations in the rpoB and katG genes and inhA promoter region (pro-inhA) associated to resistance to rifampicin and isoniazid, the two markers of multidrug-resistant TB (MDR). We assessed the performances of the test on a collection of strains (n = 54) and a set of clinical samples (n = 242) from routine practice, comparatively to TB diagnosis and genotypic drug susceptibility testing (gDST) as references. Regarding the 242 clinical samples, the sensitivity and specificity of MTB detection by ELITe were 90.9% and 97.5%, respectively. For the detection of resistance-conferring mutations on positive clinical samples, we observed perfect agreement with gDST for katG and pro-inhA (κ = 1.0) and two discordant results for rpoB (κ = 0.82). Considering the 54 cultured strains, very good agreement with gDST was observed for the detection of the 25 distinct mutations in rpoB, katG, and pro-inhA, (κ = 0.95, 0.88, and 0.95, respectively). In conclusion, the automated MDR/MTB ELITe MGB® assay shows great promise and appears to be a valuable tool for rapid detection of pre-MDR- and MDR-TB directly from clinical specimens.


Author(s):  
Horacio Gil ◽  
Hasmik Margaryan ◽  
Ismailov Azamat ◽  
Bekturdieva Ziba ◽  
Halmuratov Bayram ◽  
...  

2020 ◽  
Vol 44 (1) ◽  
Author(s):  
Kome Otokunefor ◽  
Blessing O. Famakin ◽  
Dorothy O. Douglas

Abstract Background Fomites have long been known to play a key role in the spread of disease causing agents. Hospital-associated fomites in particular have been linked with transmission of members of the Enterococci sp which are key human pathogens. Few studies have explored the role non-hospital door handles might play as potential sources of these isolates. This study therefore set out to explore this role. Results A total of hundred toilet and office door handles in a tertiary institution in Rivers State, Nigeria, were sampled using the swab and rinse method. The presence and drug susceptibility of Enterococcus was determined using the selective bile esculin agar (BEA) and standard microbiological methods. Growth on BEA was observed in 71% of cases, with more growth (38/50, 76%) observed from toilet door handles. Only 35% of samples produced the characteristic black pigmentation associated with Enterococcus sp. Six different bacterial groups were identified from this subset with Enterococcus sp. making up only 14% (5/35) of the isolates. All (100%) Enterococci were isolated from toilet door handles. Antibiotic susceptibility testing revealed very high levels of resistance (80–100%) against 75% of the test antibiotics. An analysis of the antibiotic resistance pattern of each isolate revealed 11 unique antibiogram patterns. Only 2 of these patterns were associated with the enterococci, with majority (4/5) exhibiting resistance to Augmentin (AUG), Ceftazidime (CAZ), Ceftriaxone (CTR), Cefuroxime (CRX), Cloxacillin (CXC), Erythromycin (ERY), Gentamicin (GEN), Ofloxacin (OFL) (antibiogram of AUG–CAZ–CRX–CTR–CXC–ERY). None of the enterococci, however, was resistant to vancomycin. Conclusion This study reports low level contamination of door handles by enterococci. Identical antibiogram patterns linked with majority of the enterococci could however point at the occurrence of a single clone perhaps indicating single source contamination. Reports of high levels of ampicillin resistance among these isolates are problematic as ampicillin–gentamicin combination is the treatment of choice for nosocomial enterococci pathogens.


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