Pyogenic wound infections are one of the most common clinical entities caused and aggravated by the invasion of pathogenic organisms. Prompt and aggressive antimicrobial therapy is needed to reduce the burden and complications associated with these infections. In this study, we intended to investigate the common pathogens and their antimicrobial susceptibility patterns from the pyogenic wound infections at a tertiary care hospital in Kathmandu, Nepal. A laboratory based cross-sectional study was carried out among the pyogenic clinical specimens of the patients visiting Manmohan Memorial Teaching Hospital, Kathmandu, Nepal. Processing of clinical specimens and isolation and identification of bacterial pathogens were carried out using standard microbiological methods. Antimicrobial susceptibilities and resistant profiles were determined by following the standard guidelines of Clinical and Laboratory Standards Institute (CLSI). About 65% of the clinical specimens were positive for the bacterial growth and Gram positive bacteria (57.4%) were the leading pathogens among pyogenic wound infections. Staphylococcus aureus (412, 49.28%), Escherichia coli (136, 16.27%), Klebsiella spp. (88, 10.53%), and Pseudomonas spp. (44, 5.26%) were the common pathogens isolated. High level of drug resistance was observed among both Gram positive bacteria (51.9%) and Gram negative bacteria (48.7%). Gram positive isolates were resistant to ampicillin, ciprofloxacin, cotrimoxazole, erythromycin, and cloxacillin. Gram negative isolates were resistant to cephalosporins but were well susceptible to amikacin and imipenem. Pyogenic wound infections are common in our hospital and majority of them were associated with multidrug resistant bacteria. The detailed workup of the prevalent pathogens present in infected wounds and their resistance pattern is clearly pertinent to choosing the adequate treatment.

Enteric fever caused by Salmonella enterica is a life-threatening systemic illness of gastrointestinal tract especially in tropical countries. Antimicrobial therapy is generally indicated but resistance towards commonly used antibiotics has limited their therapeutic usefulness. Therefore, we aimed to determine the antimicrobial susceptibility pattern by minimum inhibitory concentration method of common therapeutic regimens against Salmonella enterica from enteric fever clinical cases. Salmonella enterica clinical isolates recovered from the patients with suspected enteric fever whose blood samples were submitted to microbiology laboratory of Manmohan Memorial Community Hospital, Kathmandu, from March 2016 to August 2016, were studied. These isolates were subjected to antimicrobial susceptibility testing against common therapeutic antimicrobials by Kirby-Bauer disk diffusion method. The minimum inhibitory concentration of ciprofloxacin, azithromycin, chloramphenicol, and cefixime was determined by Agar dilution method based on the latest CLSI protocol. A total of 88 isolates of Salmonella enterica were recovered from blood samples of enteric fever cases. Out of them, 74 (84.09%) were Salmonella Typhi and 14 (15.91%) were Salmonella Paratyphi A. On Kirby-Bauer disk diffusion antimicrobial susceptibility testing, entire isolates were susceptible to cotrimoxazole, cefixime, ceftriaxone, azithromycin, and chloramphenicol. Sixty-four (72.7%) Salmonella enterica isolates were nalidixic acid resistant and nonsusceptible to ciprofloxacin and levofloxacin. On MIC determination, four Salmonella isolates were ciprofloxacin resistant with MIC 1 µg/ml and two isolates were ciprofloxacin intermediate with MIC 0.5 µg/ml. The MIC range of azithromycin was from 0.125 µg/ml to 2.0 µg/ml, whereas that for chloramphenicol was 2.0 µg/ml–8.0 µg/ml and for cefixime was 0.0075–0.5 µg/ml, respectively. Despite global surge of antimicrobial resistance among Salmonella enterica clinical isolates, the level of drug resistance in our study was not so high. However, higher level of NARST strains limits therapeutic use of fluoroquinolones and necessitates the routine monitoring of such resistance determinants in order to effectively and rationally manage enteric fever cases.

BackgroundFecal carriage of multidrug-resistant and extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae is one of the important risk factors for infection with antibiotic-resistant bacteria. In this report, we examined the prevalence of multidrug-resistant and ESBL-producing common enterobacterial strains colonizing the intestinal tract of apparently healthy adults in Kathmandu, Nepal.MethodsDuring a 6-month period (February–July 2016), a total of 510 stool specimens were obtained from apparently healthy students of Manmohan Memorial Institute of Health Sciences, Kathmandu, Nepal. Stool specimens were cultured, and the most common enterobacterial isolates (Escherichia coli and Klebsiella species) were subjected to antimicrobial susceptibility tests according to the standard microbiologic guidelines. Multidrug-resistant isolates were selected for ESBL confirmation by combined disk test and E-test methods. Molecular characterization of plasmid-borne ESBL genes was performed by using specific primers of cefotaximase Munich (CTX-M), sulfhydryl variant (SHV), and temoniera (TEM) by polymerase chain reaction.ResultsAmong 510 bacterial strains, E. coli (432, 84.71%) was the predominant organism followed by Klebsiella oxytoca (48, 9.41%) and K. pneumoniae (30, 5.88%). ESBLs were isolated in 9.8% of the total isolates including K. oxytoca (29.17%), E. coli (7.87%), and K. pneumoniae (6.67%). Among ESBLs, bla-TEM was the predominant type (92%) followed by bla-CTX-M (60%) and bla-SHV (4%).ConclusionMultidrug-resistant and ESBL-producing enterobacterial commensal strains among healthy individuals are of serious concern. Persistent carriage of ESBL organisms in healthy individuals suggests the possibility of sustained ESBL carriage among the diseased and hospitalized patients. We recommend similar types of epidemiologic surveys in larger communities and in hospital settings to ascertain the extent of ESBL resistance.

Bacteriophages are being the subject of interest for alternative antimicrobial therapy for infectious diseases in recent years. Therapeutic effectiveness regarding phage therapy is a matter of concern since it is the most promising biological treatment of this era. Hence, the present study was aimed to isolate the potential bacteriophages present in river water samples and to analyze their host range among clinical strains of bacteria. Ten different locations of Kathmandu valley were selected for the collection of river water for the detection of probable phages. Bacteriophages were isolated from water samples using the double agar overlay method. Isolated phages were purified by diluting in the SM-buffer and filtering through 0.22 μm filter. Purified lysate was further processed for analyzing its host range by using spot method. Their host range was characterized against 20 bacterial strains, including multidrug-resistant. Total 67 different phages were isolated against 8 different host organisms. Out of them, forty-seven phages were selected for analyzing its host range. Among them, Serratia phages (ΦSER) had the broad host range infecting 17 different bacterial strains including multidrug-resistant harboring ESBL and MBL genotypes. However, Klebsiella phages (ΦKP) had narrow host range in comparison to other phages. Isolated phages had the potential effect against clinical strains of bacteria along with their broader host spectrum. Most importantly, promising effect against MDR pathogens in this study has raised the probable chances of the utility of these phages for biological control of bacterial infection including MBL and ESBL strains.

Chromobacterium violaceum is a gram negative saprophytic bacterium, prevalent in tropical and subtropical climates. Infections caused by C. violaceum are very uncommon, yet it can cause severe systemic infections with higher mortality when entered into the bloodstream through open wound. A case of symptomatic bacteremia in a woman caused by C. violaceum was identified recently at a tertiary care teaching hospital in Nepal. Timely diagnosis by microbiological methods and rapid administration of antimicrobials led to a successful treatment of this life-threatening infection in this case. From this experience, we suggest to include this bacterium in the differential diagnosis of sepsis, especially when abraded skin is exposed to soil or stagnant water in tropical areas. The precise antimicrobial selection and timely administration should be considered when this infection is suspected.