BackgroundUrinary Tract Infection (UTI) is one of the most common infectious diseases and people of all age-groups and geographical locations are affected. The impact of disease is even worst in low-resource developing countries due to unaware of the UTIs caused by multidrug-resistant (MDR) pathogens and the possibility of transfer of MDR traits between them. The present study aimed to determine the prevalence of MDR bacterial isolates from UTI patients, the antibiotic resistance pattern and the conjugational transfer of multidrug resistance phenotypes in Escherichia coli (E. coli).ResultsTwo hundred and nineteen bacterial isolates were recovered from 710 urine samples at Kathmandu Model hospital during the study period. All samples and isolates were investigated by standard laboratory procedures. Among the significant bacterial growth (30.8%, 219 isolates), 41.1% isolates were MDR. The most prevailing organism, E. coli (81.3%, 178 isolates) was 38.2% MDR, whereas second most common organism, Citrobacter spp. (5%, 11 isolates) was found 72.7% MDR. Extended-spectrum β-lactamase (ESBL) production was detected in 55.2% of a subset of MDR E. coli isolates. Among the 29 MDR E. coli isolates, plasmids of size ranging 2-51 kb were obtained with different 15 profiles. The most common plasmid of size 32 kb was detected in all of the plasmid-harbored E. coli strains. The majority of E. coli isolates investigated for the multidrug resistance transfer were able to transfer plasmid-mediated MDR phenotypes along with ESBL pattern with a frequency ranging from 0.3 × 10-7 to 1.5 × 10-7 to an E. coli HB101 recipient strain by conjugation. Most of the donor and recipient strain showed high levels of minimum inhibitory concentration (MIC) values for commonly-used antibiotics.ConclusionsThe high prevalence of multidrug resistance in bacterial uropathogens was observed. Particularly, resistance patterns were alarmingly higher for amoxycillin, co-trimoxazole, flouroquinolones and third-generation cephalosporins, which necessitate the re-evaluation of first and second line therapies for UTI. In addition, conjugational co-transfer of MDR phenotypes with ESBL-positive phenotypes was observed in MDR E. coli.

BackgroundExtended spectrum beta-lactamase (ESBL) and metallo beta-lactamase (MBL) production in Klebsiella pneumoniae and Escherichia coli are the commonest modes of drug resistance among these commonly isolated bacteria from clinical specimens. So the main purpose of our study was to determine the burden of ESBL and MBL production in E. coli and K. pneumoniae isolated from clinical samples. Further, the antimicrobial susceptibility patterns of E. coli and K. pneumoniae were also determined.MethodsA cross-sectional study was conducted at Om Hospital and Research Centre, Kathmandu, Nepal by using the E. coli and K. pneumoniae isolated from different clinical samples (urine, pus, body fluids, sputum, blood) from May 2015 to December 2015. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique. Extended spectrum beta-lactamase production was detected by combined disc method using ceftazidime and ceftazidime/clavulanic acid discs and cefotaxime and cefotaxime/clavulanic acid discs. Similarly, metallo beta-lactamase production was detected by combined disc assay using imipenem and imipenem/ethylenediaminetetracetate discs. Bacteria showing resistance to at least three different classes of antibiotics were considered multidrug resistant (MDR).ResultsOf total 1568 different clinical samples processed, 268 (17.1%) samples were culture positive. Among which, E. coli and K. pneumoniae were isolated from 138 (51.5%) and 39 (14.6%) samples respectively. Of the total isolates 61 (34.5%) were ESBL producers and 7 (4%) isolates were found to be MBL producers. High rates of ESBL production (35.9%) was noted among the clinical isolates from outpatients, however no MBL producing strains were isolated from outpatients. Among 138 E. coli and 39 K. pneumoniae, 73 (52.9%) E. coli and 23 (59%) K. pneumoniae were multidrug resistant. The lowest rates of resistance was seen toward imipenem followed by piperacillin/tazobactam, amikacin and cefoperazone/sulbactam.ConclusionsHigh rate of ESBL production was found in the E. coli and K. pneumoniae isolated from outpatients suggesting the dissemination of ESBL producing isolates in community. This is very serious issue and can’t be neglected. Regular monitoring of rates of ESBL and MBL production along with multidrug resistance among clinical isolates is very necessary.

A number of nucleic acid amplification assays (NAAs) have been employed to detect tubercle bacilli in clinical specimens for tuberculosis (TB) diagnosis. Among these, loop-mediated isothermal amplification (LAMP) is an NAA possessing superior isothermal reaction characteristics. In the present study, a set of six specific primers targeting the Mycobacterium tuberculosis 16S rRNA gene with high sensitivity was selected and a LAMP system (MTB-LAMP) was developed. Using this system, a total of 200 sputum samples from Nepalese patients were investigated. The sensitivity of MTB-LAMP in culture-positive samples was 100 % (96/96), and the specificity in culture-negative samples was 94.2 % (98/104, 95 % confidence interval 90.5-97.9 %). The positive and negative predictive values of MTB-LAMP were 94.1 and 100 %, respectively. These results indicate that this MTB-LAMP method may prove to be a powerful tool for the early diagnosis of TB.

Seventy-nine Actinomycetes were isolated from soils of Kalapatthar (5545m), Mount Everest region. Twenty seven (34.18%) of the isolates showed an antibacterial activity against at least one test-bacteria among two Gram positive and nine Gram negative bacteria in primary screening by perpendicular streak method. Thirteen (48.15%) showed antibacterial activity in secondary screening. The result showed that three of the isolates, K.6.3, K.14.2, and K.58.5 were highly active with an inhibition zone e"20mm and broad spectrum antibacterial activity including two methicillin resistant Staphylococcus aureus (MRSA) strains. Minimum inhibitory concentration (MIC) of antibacterial metabolites of the isolate K.6.3 was 1mg/ml, and that of isolates K.14.2 and K.58.5 was 2mg/ml. Two spots were detected on thin layer chromatography plate from each of the metabolites which was completely different from the spot produced by vancomycin. The active isolates from primary screening were heterogeneous in their overall macroscopic, biochemical, and physiological characteristics through unweighted pair group method using average (UPGMA) cluster analysis. Delineation of the three active isolates showing potent broad spectrum antibacterial activity revealed that they belonged to distinct taxonomic groups.

BackgroundEnteric fever is an important public health problem in Nepal. Due to emergence of multidrug resistant strains of Salmonella spp. the conventional first-line drugs, ampicillin, chloramphenicol, and cotrimoxazole have not been used as empiric therapy for treatment of enteric fever for last two decades and there have been increased uses of fluoroquinolones as the drugs of choice. The aim of this study was to evaluate and analyze the antimicrobial susceptibility patterns of Salmonella spp.MethodsA total of 620 blood samples collected from the patients suspected of suffering from enteric fever were cultured using standard microbiological techniques. Antibiotic susceptibility testing of the Salmonella spp., was performed by Kirby Bauer disc diffusion technique following Clinical and Laboratory Standard Institute (CLSI) guidelines. Minimum inhibitory concentrations of ciprofloxacin, ofloxacin and nalidixic acid were determined by agar dilution method.ResultsOf the total 83 Salmonella spp., 48 (57.83 %) were S. Typhi and 35 (42.26 %) were S. Paratyphi A. Among 83 Salmonella isolates, 98.8 % of the Salmonella spp. were susceptible to chloramphenicol and co-trimoxazole and about 97.6 % of the isolates were susceptible to ampicillin. Similarly, 69 (83.13 %) isolates were resistant to nalidixic acid. Only 16.9 % of the isolates were susceptible to ciprofloxacin. One S. Typhi isolate was multidrug resistant.ConclusionThe present study revealed the decreased susceptibility of the S. Typhi and S. Paratyphi A to fluoroquinolones, proving them to be inappropriate for empirical therapy for the treatment of enteric fever in our setting. Further the higher susceptibility of the isolates to first line drugs, ampicillin, chloramphenicol, and cotrimoxazole suggests the possibility of using these drugs for empirical therapy.

BackgroundThe increasing drug resistance along with inducible clindamycin resistance, methicillin resistance and biofilm production among the strains of Staphylococcus aureus are present as the serious problems to the successful treatment of the infections caused by S. aureus. So, the main objectives of this study were to determine the antimicrobial susceptibility patterns along with the rates of inducible clindamycin resistance, methicillin resistance and biofilm production among the strains of S. aureus isolated from pus/wound swab samples.MethodsA total of 830 non-repeated pus/wound swab samples were processed using standard microbiological techniques. The colonies grown were identified on the basis of colony morphology, Gram’s stain and biochemical tests. Antimicrobial susceptibility testing was performed by Kirby–Bauer disc diffusion technique. Detection of inducible clindamycin resistance was performed by D test, while detection of methicillin resistant S. aureus (MRSA) was performed by determination of minimum inhibitory concentration of oxacillin by agar dilution method. Similarly, detection of biofilm formation was performed by microtiter plate method. Strains showing resistance to three or more than three different classes of antibiotics were considered multidrug resistant.ResultsTotal 76 samples showed the growth of S. aureus, among which 36 (47.4%) contained MRSA and 17 (22.4%) samples were found to have S. aureus showing inducible clindamycin resistance. Among the S. aureus isolated from outpatients, 41.9% were MRSA. Highest rates of susceptibility of S. aureus were seen toward linezolid (100%) and vancomycin (100%). Similarly, S. aureus isolated from 35 (46.1%) samples were found to be biofilm producers. Higher rate of inducible clindamycin resistance was seen among MRSA in comparison to methicillin susceptible S. aureus (MSSA). Similarly, higher rates of multidrug resistance and methicillin resistance were found among biofilm producing strains in comparison to biofilm non producing strains.ConclusionsThe rate of isolation of MRSA from community acquired infections was found to be high in Nepal. Increased rate of inducible clindamycin resistance as compared to previous studies in Nepal was noted. So for the proper management of the infections caused by S. aureus, D test for the detection of inducible clindamycin resistance should be included in the routine laboratory diagnosis. Further, detection of biofilm production should also be included in the routine tests. Linezolid and vancomycin can be used for the preliminary treatment of the serious infections caused by S. aureus.

BackgroundMethicillin resistant Staphylococcus aureus (MRSA) has evolved as a serious threat to public health. It has capability to cause infections not only in health care settings but also in community. Due to the multidrug resistance shown by MRSA, there are limited treatment options for the infections caused by this superbug. Vancomycin is used as the drug of choice for the treatment of infections caused by MRSA. Different studies from all around the world have documented the emergence of strains of S. aureus those are intermediate sensitive or resistant to vancomycin. And recently, there have been reports of reduced susceptibility of MRSA to vancomycin, from Nepal also. So the main purpose of this study was to determine the minimum inhibitory concentration (MIC) of vancomycin to methicillin resistant S. aureus isolated from different clinical specimens.MethodsTotal 125 strains of S. aureus isolated from different clinical samples at KIST Medical College and Teaching Hospital, Lalitpur, Nepal from Nov 2012 to June 2013, were subjected to MRSA detection by cefoxitin disc diffusion method. The minimum inhibitory concentrations of vancomycin to confirmed MRSA strains were determined by agar dilution method. Yellow colored colonies in mannitol salt agar, which were gram positive cocci, catalase positive and coagulase positive were confirmed to be S. aureus.ResultsAmong, total 125 S. aureus strains isolated; 47(37.6%) were MRSA. Minimum inhibitory concentrations of vancomycin to the strains of MRSA ranged from 0.125 μg/ml to 1 μg/ml.ConclusionFrom our findings we concluded that the rate of isolation of MRSA among all the strains of S. aureus isolated from clinical samples was very high. However, none of the MRSA strains were found to be vancomycin intermediate-sensitive or vancomycin-resistant.

In Nepal, little is known about the microbiological profile of wound infections in children and their antimicrobial susceptibility patterns. Total of 450 pus/wound swab samples collected were cultured using standard microbiological techniques and the colonies grown were identified with the help of biochemical tests. The antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique. Methicillin-resistant Staphylococcus aureus isolates were detected by using cefoxitin disc and confirmed by determining minimum inhibitory concentrations (MIC) of oxacillin. 264 (59%) samples were culture positive. The highest incidence of bacterial infections was noted in the age group of less than 1 year (76%). Out of 264 growth positive samples, Gram-positive bacteria were isolated from 162 (61%) samples and Gram-negative bacteria were found in 102 (39%) samples. Staphylococcus aureus (99%) was the predominant Gram-positive bacteria isolated and Pseudomonas aeruginosa (44%) was predominant Gram-negative bacteria. About 19% of S. aureus isolates were found to be methicillin-resistant MIC of oxacillin ranging from 4 μg/mL to 128 μg/mL. Among the children of Nepal, those of age less than 1 year were at higher risk of wound infections by bacteria. Staphylococcus aureus followed by Pseudomonas aeruginosa were the most common bacteria causing wound infections in children.