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Objective: This study aimed to identify subspecies of Mycobacterium abscessus complex (MABC) isolates from clinical samples by a molecular technique and to determine mutations responsible for macrolide and aminoglycoside resistance. We also aimed to investigate the correlation of phenotypic and molecular test results by examining the resistance to antimicrobial agents according to CLSI standard using the liquid microdilution test. Methods: 27 MABC isolates from clinical samples were examined. Molecular subspecies identification and mutations responsible for aminoglycoside (rrs mutation) and macrolide resistance (rrl mutation) were determined using the GenoType NTM-DR test. The resistance phenotypes of the strains to various antimicrobial agents were investigated by the Sensititre™ RAPMYCOI AST microdilution test. Results: Of the 27 isolates tested, 21 were M. abscessus subsp. abscessus, three were M. abscessus subsp. bolletii, and three were M. abscessus subsp. massiliense; rrs and rrl mutations were not observed in any strains. Except for one isolate, all M. abscessus subsp. abscessus strains showed the erm(41) T28 genotype, which indicates inducible macrolide resistance. The correlation between the GenoType NTM-DR and phenotypic susceptibility test results was 81% (k=0.5, p=0.02) for inducible macrolide resistance and 89% for acquired macrolide resistance. The most effective antimicrobial agents were amikacin, cefoxitin, imipenem, linezolid, and tigecycline. Conclusion: Although the GenoType NTM-DR test is reliable in identifying and detecting molecular macrolide and aminoglycoside resistance, there were discrepancies in the results. We recommend confirming the results with the phenotypic susceptibility method after growth on culture. Although the M. abscessus complex is resistant to many antimicrobial agents, it has shown high sensitivity to amikacin, cefoxitin, imipenem, linezolid, and tigecycline. High levels of inducible macrolide resistance in isolates indicate the importance of subtyping and sensitivity testing of isolates in patients where culture conversion has not been achieved. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study is to compare of the results of LED fluorescent microscopy (LED FM) and Ehrlich Ziehl Neelsen (EZN) staining in the examination of the respiratory specimens and to evaluate the performance of LED fluorescent microscopy with culture. Methods: In the study, the respiratory specimens obtained from patients prediagnosed with pulmonary tuberculosis were examined in the Tuberculosis Laboratory of Manisa Celal Bayar University Hafsa Sultan Hospital between February 2018 and November 2019. Two smears from each specimen processed with NALC-NaOH method were prepared and they were evaluated both EZN and LED FM by blind readers. The results of culture were used as reference for determination of the performance of LED FM. Results: In the study 1499 respiratory specimens were evaluated with LED FM. Mycobacteria were grown in the culture of 134 specimens (8.9%). The sensitivity, specificity, positive predictive value, and negative predictive value of LED FM were found as 64.2% (95% GI, 61.8%-64.4%), 96% (95%GI, 95.7%-96.3%), 61.4% and Makale Dili "Türkçe"/Article Language "Turkish" 96.5%, respectively. The sensitivity, specificity, positive and negative predictive values of EZN were also found as 51.5% (95% GI, 49%-54%), 99.9% (95% GI, 99.7%-99.9%), 97.2% and 95.4%, respectively. However, smear scarceculture negative results (54/1365) with LED FM were obtained significantly higher than the results with EZN (0/1365, p=0.000). The reason of this was thought to be due to the lack of the experience of the readers. The reading time of LED FM was 69% time saving. The consistency between the readers was found to be good (Kappa value=0.71) and it was determined that LED FM could be preferred in routine examination as a result of the survey conducted to the readers. Conclusion: The sensitivity of LED FM was found 12.7% higher than the sensitivity of EZN. However, because of the high rate of false positive results, the introduction of LED-FM should be accompanied by appropriate training of the readers. It is also thought that the use of LED FM will be cost-effective in largescale laboratories in our country. [ABSTRACT FROM AUTHOR]

Byline: Aylin. Ermertcan, Nuri. Özkütük, Peyker. Temiz, Cengiz. Çavu?o?lu, Süheyla. Sürücüo?lu A 54-year-old man presented with multiple draining sinuses on the right hand for 2 years. Dermatological examination revealed erythematous [...]

Immunogenic potency of the recombinant Erp, HspR, LppX, MmaA4, and OmpA proteins from Mycobacterium tuberculosis (MTB), formulated with Montanide ISA 720 VG adjuvant, was evaluated in BALB/c mice for the first time in this study. The five vaccine formulations, adjuvant, and BCG vaccine were subcutaneously injected into mice, and the sera were collected at days 0, 15, 30, 41, and 66. The humoral and cellular immune responses against vaccine formulations were determined by measuring serum IgG and serum interferon-gamma (IFN-γ) and interleukin-12 (IL-12) levels, respectively. All formulations significantly increased IgG levels post-vaccination. The highest increase in IFN-γ level was provided by MmaA4 formulation. The Erp, HspR, and LppX formulations were as effective as BCG in enhancement of IFN-γ level. The most efficient vaccine boosting the IL-12 level was HspR formulation, especially at day 66. Erp formulation also increased the IL-12 level more than BCG at days 15 and 30. The IL-12 level boosted by MmaA4 formulation was found to be similar to that by BCG. OmpA formulation was inefficient in enhancement of cellular immune responses. This study showed that MmaA4, HspR, and Erp proteins from MTB are successful in eliciting both humoral and cellular immune responses in mice. [ABSTRACT FROM AUTHOR]

OBJECTIVES: The aim of the study was to evaluate the levels of interleukin (IL)-4, IL-10, transforming growth factor-beta (TGF-β), IL-1 7, and IL-23 cytokines, which reflect different T lymphocyte responses, in bronchoalveolar lavage (BAL) samples of tuberculin skin test (TST)-positive children. MATERIAL AND METHODS: Twelve children with TST positivity, who underwent flexible videobronchoscopy (FB) to evaluate airway involvement and to obtain BAL to improve diagnostic yield, and 11 control children with negative TST, who underwent FB for other reasons, were enrolled in this case-control study. BAL samples were obtained from all children during the FB procedure. Levels of IL-4, interferon gamma (IFN-γ), IL-10, TGF-β, IL-1 7, and IL-23 were measured by the ELISA method. RESULTS: Mean age of the children enrolled in the TST-positive and -negative groups were 8.6 (4.3) vs. 6.8 (4.5), respectively (p=0.35). There was a trend of higher TGF-β levels in TST-positive children compared with TST-negative children [557.9 (515.3) vs. 386.3 (208.1), respectively, p=0.07]. Mean levels of IL-23 were 39.2 (29.5) in TST-positive children vs. 46.2 (72.3) in TST-negative children (p=0.49). IFN-γ, IL-4, IL-10, and IL-1 7 levels were not significantly different among the groups (p>0.05 for all). CONCLUSION: Results of this study suggest that TGF-β in BAL fluid of children with TST positivity tends to be higher than that in TST-negative children, which indicates an increased activity of regulatory T lymphocytes that may decrease the Th1 immune response. TGF-γ might be studied in future research for its potential as a diagnostic modality and immunomodulatory treatment target. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to investigate the molecular diversity and clonal relationship of drug resistant Mycobacterium tuberculosis strains isolated in Western Turkey. Materials and Methods: A total of 87 strains isolated between 2006 and 2009, eight of which were rifampicin monoresistant and 79 were multidrug resistant, were analyzed with IS6110 RFLP and spoligotyping methods. Results: The results of spoligotyping showed that 7% of the strains were orphans, and 8% were undefined for family in the SpolDB4 database. Major families of the strains were LAM (38%), T (35%), Haarlem (7%), Beijing (2%), S (2%) and U (1%) families. The clustering rate by spoligotyping was calculated as 75%. The most predominant SIT cluster was SIT41 (29%). According to the results of IS6110 RFLP, 71 different patterns of IS6110 were observed. Low copy number was found in 26% of the strains. When the results of two methods were combined, the final clustering rate was calculated as 26%. Conclusions: The genotypical distribution of drug resistant tuberculosis isolates in our region indicates genetic diversity and the clustering rate was found low in our region. However, more comprehensive and long-term molecular epidemiological studies are needed to control the drug resistant strains. [ABSTRACT FROM AUTHOR]

Copyright of Klimik Journal / Klimik Dergisi is the property of DOC Design & Informatics Co. Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Klimik Journal / Klimik Dergisi is the property of DOC Design & Informatics Co. Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aim: The emergence of multidrug-resistant tuberculosis (MDR-TB) is increasing, and the standard short-course regimen used for the treatment of TB is likely to be ineffective against MDR-TB, leading to the need for second-line drugs. In such situations, drug susceptibility testing is necessary to select an appropriate treatment regimen. Unfortunately, there are few studies showing the pattern of the second-line drug resistance in Turkey. We aimed to analyze the resistance to second-line anti-tuberculosis drugs of MDR strains of Mycobacterium tuberculosis isolated from the Aegean region of Turkey. Materials and Methods: In this study, drug susceptibility testing of 40 MDR-TB strains isolated from the Aegean region of Turkey was performed using the BACTEC 460 TB radiometric system. Capreomycin, ethionamide, kanamycin, amikacin, clofazimine and ofloxacin were tested in 1.25 μg/ml, 1.25 μg/ml, 5.0 μg/ml, 1.0 μg/ml, 0.5 μg/ml, and 2.0 μg/ml concentrations, respectively. Results: The results showed that 37.5% of the strains were resistant to ethionamide, 25% to capreomycin, 5% to kanamycin, amikacin and ofloxacin, and 2.5% to clofazimine. One (2.5%) of the 40 MDR-TB cases was defined as extensively drug-resistant tuberculosis (XDR-TB). Conclusions: The results of the study indicate that the high rates of resistance to ethionamide and capreomycin may be a problem in the treatment of patients with MDR-TB; XDR-TB is not yet a serious problem in our region. [ABSTRACT FROM AUTHOR]

Mycobacterium abscessus complex (MABSC) is one of the most resistant bacteria against antimicrobial agents. The number of agents that can be used by oral route, such as macrolides, is limited in antimicrobial therapy. In recent years, rifabutin and clofazimine have gained importance as they can be administered by oral route and have shown synergistic effects with macrolides and aminoglycosides. The aim of this study was to determine the in vitro activity of rifabutin and clofazimine against clinical isolates of MABSC resistant to macrolides. A total of 48 MABSC isolates obtained from respiratory tract and other clinical samples in the Tuberculosis Laboratories of the Faculty of Medicine of Manisa Celal Bayar and Ege Universities were included in the study. Subspecies differentiation and aminoglycoside and macrolide resistance of the isolates were determined by GenoType NTM-DR test. Rifabutin and clofazimine susceptibilities were determined by standard broth microdilution method. Of the MABSC isolates 42 were identified as M.abscessus subsp. abscessus, three as M.abscessus subsp. bolletii and three as M.abscessus subsp. massiliense. None of the isolates exhibited rrs and rrl mutations indicating acquired macrolide resistance and aminoglycoside resistance. However, the erm(41) T28 genotype which is associated with inducible macrolide resistance was detected in 41 (85%) of the strains. All M.abscessus subsp. massiliense isolates were found to be genotypically susceptible to macrolides. The minimum inhibitory concentration (MIC) range values for rifabutin were 0.0625 to 32 µg/mL, while for clofazimine, the range was 0.0625 to 1 µg/mL. Rifabutin MIC values were significantly higher (mean 5.98 µg/mL vs 0.5 µg/mL, p= 0.026) in the isolates with macrolide resistance. There was no correlation between macrolide resistance and clofazimine MIC values (mean 0.25 µg/mL vs. 0.214 µg/mL, p= 0.758). The MIC50 and MIC90 values for rifabutin were 1 and 8 µg/mL, respectively, while for clofazimine they were 0.25 and 0.5 µg/mL. Macrolide resistance was found to be higher in isolates with rifabutin MIC values above the MIC50 value (p= 0.045). In conclusion, the determination of higher rifabutin MIC values in isolates resistant to macrolides suggested that susceptibility testing should be performed before adding rifabutin to the treatment regimen. The low MIC values of clofazimine in all strains indicated that it may be used as a first choice in the combination therapy. However, further studies using a larger number of clinical isolates and applying genotypic and phenotypic susceptibility tests are needed to determine threshold MIC values to assist clinicians in making treatment decisions.

Tuberculosis has spread by human movements throughout history. There have been reports indicating tuberculosis transmission on all travel vehicles, including aircrafts, ground vehicles and vessels until today. However, due to the ever increasing of air transportation and air travelling among countries with low and high tuberculosis incidence, transmission risk especially in aircrafts has become an important issue worldwide. But in many of the studies conducted in this regard, transmission of tuberculosis in aircrafts was found very low. The case of active tuberculosis has not yet been reported. This is due to the fact that in modern aircrafts, there are ventilation systems that provide hepa filtered laminar air flow and change the air 15-20 times per hour. The guidelines for the prevention of tuberculosis infection in aircrafts published by the World Health Organization "Tuberculosis and Air Travel, 2008" and European Centre for Disease Prevention and Control "RAGIDA-TB, 2014" confirm each other. According to these guidelines, air travelling of patients with active pulmonary tuberculosis should be prohibited until smears of two consecutive sputum samples become negative for drug susceptible cases, and cultures of two consecutive of sputum samples become negative for multidrug or extensively drug resistant cases. When it is reported that a tuberculosis patient has travelled by the aircraft, it is recommended that the exposed passengers should be investigated for tuberculosis infection if the flight duration equal to or exceeding eight hours including ground delays and the time elapsed between flight and diagnosis of the case is no longer than three months. Contact screening is only recommended for passengers sitting in the same row, two rows ahead and two rows behind the index case. Tuberculin skin test or interferon gamma release assay can be used for investigation. It is very difficult to determine the risk of tuberculosis transmission in ground vehicles like buses, subways and trains. The reason is that it is often not possible to access the information of the passengers travelling in these vehicles. Because the ventilation systems in ground vehicles are not as reliable as in aircrafts and the crowded environment in the ground vehicles, the risk of tuberculosis transmission is theoretically higher. In modelling studies, the transmission risk in the buses was found to be higher than the trains. In the case of regular travelling with an index case such as school bus riders, the risk increases significantly. The increased human population travelling all over the world nowadays has also raised concerns about travel-related tuberculosis risk. However, because of the limited evidence, it may be more efficient to spend time and resources for the other actions in order to prevent tuberculosis. In this review article, the transmission risk of tuberculosis in vehicles has been discussed.

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 Mayıs 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.

Community-acquired pneumonia (CAP) is still a serious life-threatening disease, in which the etiologic agent cannot be identified in more than 50% of patients despite advanced diagnostic methods. The most commonly used methods in the determination of CAP etiology are culture and serological tests. Since early and accurate therapy reduces the mortality in CAP cases, rapid and reliable diagnostic methods are needed. The aim of this study was to determine the bacterial etiology in adult patients with CAP by implementing multiplex polymerase chain reaction/reverse line blot hybridization (M-PCR/RLBH) assay combined with conventional methods. A total of 128 cases (94 were male; age range: 19-81 years, mean age: 58) who were admitted to our hospital and clinically diagnosed as CAP between November 2008 - November 2010, were included in the study. Respiratory samples (sputum and/or bronchoalveolar lavage) obtained from patients were searched by M-PCR/RLBH method (Gen ID®, Autoimmun Diagnostika GmbH, Germany) in terms of the presence of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma pneumoniae, Chlamydia pneumoniae and Legionella pneumophila nucleic acids. The samples were simultaneously inoculated onto 5% sheep blood agar, chocolate agar, haemophilus isolation agar, buffered charcoal yeast extract-selective agar and EMB agar media for cultivation. Serum samples obtained from the cases were tested for IgM and IgG antibodies against C.pneumoniae by microimmunofluorescence (Focus Diagnostic, USA) and against L.pneumophila and M.pneumoniae by indirect immunofluorescence (Euroimmun, Germany) methods. The bacterial etiology was identified in 59 (46.1%) of 128 patients with CAP and a total of 73 pathogens were detected. The leading organism was S.pneumoniae (n= 32, 25%), followed by H.influenzae and M.pneumoniae (n= 9, 7%), gram-negative bacilli (n= 10, 7.8%), M.catarrhalis (n= 6, 4.7%), C.pneumoniae (n= 4, 3.2%), L.pneumophila (n= 2, 1.6%) and Staphylococcus aureus (n= 1, 1.4%). Infection with atypical pathogens were detected in 15 (11.7%), and mixed infections in 14 (10.9%) patients. The detection rate of microorganisms (S.pneumoniae, H.influenzae, M.catarrhalis, C.pneumoniae, L.pneumophilia, M.pneumoniae) searched by M-PCR/RLBH method was 41.4% (53/128), while those microorganisms were detected in 23.4% (30/128) of the patients by conventional methods, representing a significant difference (p< 0.05). It was concluded that M-PCR/RLBH method supplemented the determination of bacterial etiology in CAP cases by increasing the rate of detection from 23.4% to 41.4%. The results indicated that empirical treatment of CAP should primarily include antibiotics against S.pneumoniae, M.pneumoniae and H.influenzae in our region.

Pyrazinamide (PZA) is a primary antituberculous drug. BACTEC 460TB is the recommended reference method for the detection of PZA resistance in Mycobacterium tuberculosis. This method is more expensive than the conventional susceptibility methods and therefore, it is recommended that each laboratory should establish their own protocol for the inclusion of PZA in the panel of primary drugs tested. One of the most important factors that help this decision is the prevalence of PZA resistance, particularly PZA monoresistance in the related community. The aim of the present study was to determine the extent of PZA monoresistance in M. tuberculosis complex (MTBC) isolates in our region. In this study, PZA susceptibility testing of 109 MTBC strains (susceptible to isoniazid, rifampicin, ethambutol and streptomycin) isolated from Manisa province in the Aegean region of Turkey was performed by using the BACTEC 460TB radiometric system (Becton Dickinson, MD). Two (1.8%) of the 109 isolates which were susceptible to all primary drugs revealed monoresistance against PZA. One of the PZA-monoresistant isolates has been identified as M. bovis and the other as M. tuberculosis by molecular method (Genotype MTBC, Hain Lifescience, Germany). The results of our study indicated that since the rate of PZA monoresistance was low, susceptibility testing of a panel of primary drugs without PZA may be an economical alternative in our region.

Tuberculin skin test which is used for the detection of latent tuberculosis (TB), has many disadvantages such as false positivities due to cross reactions between environmental mycobacteria and BCG strain, false negativities due to immunosuppression and malpractice, and also difficulties in application and evaluation. Recently a new diagnostic test which measures the production of interferon (IFN)-gamma in whole blood upon stimulation with specific ESAT-6 and CFP-10 antigens of Mycobacterium tuberculosis has been introduced. Since most of the mycobacteria other than tuberculosis and BCG strain do not contain these antigens, the detection of IFN-gamma levels indicates the specific T-cell response against M. tuberculosis. The aim of the study was to compare the tuberculin skin test and whole blood IFN-gamma assay (QuantiFERON-TB Gold, Cellestis Ltd, Carnegie, Victoria, Australia) for the identification of latent TB infection in the contacts with active TB patients. The tests results were evaluated by using Kappa (K) analysis, and K coefficients of < 0.4, 0.4-0.75 and > 0.75 were accepted as poor, moderate and excellent agreements, respectively. A total of 233 subjects from three risk groups were included to the study. Group 1 included the household members (n = 133) who had contact with smear positive index cases, Group 2 included the subjects from community (n = 46) who had contact with smear positive index cases, and Group 3 included health care workers (n = 74) who had contact with TB patients or their specimens. The positivity rates of tuberculin skin test and IFN-gamma assay in the cases were found as 37% and 42%, respectively. There were no significant differences among the three patient groups with regard to the results of the tuberculin skin test (p > 0.05). However, the positive result of the IFN-gamma assay in Group 1 was found statistically higher than the other groups (51.3%, p = 0.013). A poor agreement between the two tests was detected in the results taken from 233 subjects (65.7%, K = 0.28), while agreement was moderate in unvaccinated group (72.7%, K = 0.44). Evaluation of agreement rates of the tests according to the risk groups yielded 64.6% (K = 0.3) for Group 1, 71.7% (K = 0.32) for Group 2, and 63.5% (K = 0.21) for Group 3, which all coefficients showed poor agreement. Although IFN-gamma blood assay has many advantages such as objective and quantitative results, no interference with vaccination due to the use of specific antigens and being practical, the high cost and the need for well-equipped laboratory are its disadvantages. As a result it was concluded that, IFN-gamma blood assay has limited value for the detection of latent TB infection in our country, since the prevalence of TB infection and BCG vaccination rates are high in Turkey.

Background & Objectives: Information on oropharyngeal carriage rates of Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus pyogenes and Moraxella catarrhalis and their resistance pattern in healthy school children in Turkey is lacking. The present study was undertaken to determine the carriage rates and antimicrobial resistance of these bacterial pathogens in such children aged 6-14 yr in Manisa, Turkey., Methods: A total of 1022 children were included from nine schools selected randomly from 32 schools. Throat swabs were cultured for bacteria which were identified using standard microbiological methods. Antimicrobial susceptibility was determined as per National Committee for Clinical Laboratory Standards guidelines., Results: Of the 1022 children 240 (23.4%) harboured S. pneumoniae, 162 (15.8%) H. influenzae, 30 (2.9%) S. pyogenes and 82 (8%) M. catarrhalis in their oropharynx. For S. pneumoniae overall 17.9 per cent of the isolates were intermediately and 7 per cent were resistant to penicillin and resistance to erythromycin trimethoprim-sulphamethoxasole (TMP/SMX), and chloramphenicol was 13.7, 9.1 and 1.6 per cent, respectively. Ampicillin resistance observed in 20.9 per cent of H. influenzae isolates was associated with the presence of beta-lactamase, except two isolates interpreted as beta-lactamase-negative ampicillin resistant strains. Resistance of H. influenzae to TMP/SMX, chloramphenicol, azithromycin, cefaclor and amoxicillin/clavulanic acid was 14.2, 2.4, 1.8, 1.2 and 1.2 per cent, respectively. M.catarrhalis isolates produced beta-lactamase in 80.5 per cent of the cases and all were susceptible to macrolides and clavulanic acid/amoxicillin combination; the highest rate of resistance of 17 per cent was for TMP/SMX. One (3.3%) isolate of S. pyogenes was resistant to macrolides tested., Interpretation & Conclusion: Our data shows that upper respiratory tract of about 50 per cent children was colonized with respiratory pathogens. There is a need for surveillance of nasopharyngeal carriage of resistant strains in healthy school children.