Emergence of Various NDM-Type-Metallo-ß-Lactamase-Producing Escherichia coli Clinical Isolates in Nepal.

Of 250 clinical isolates of Escherichia coli obtained in Nepal, 38 were carbapenem resistant, with MICs of imipenem or meropenem of ≥4 µg/ml. All 38 isolates harbored the following blaNDMs: blaNDM-1, blaNDM-3, blaNDM-4, blaNDM-5, blaNDM-7, blaNDM-12, and blaNDM-13 Most of these isolates also harbored the 16S rRNA methylase gene(s) armA, rmtB, and/or rmtC.

Identification of a novel NDM variant, NDM-13, from a multidrug-resistant Escherichia coli clinical isolate in Nepal.

A novel New Delhi metallo-ß-lactamase, NDM-13, was identified in a carbapenem-resistant Escherichia coli clinical isolate obtained from the urine of a patient in Nepal. The enzymatic activity of NDM-13 against ß-lactams was similar to that of NDM-1. However, NDM-13 displayed significantly higher k cat/Km ratios for cefotaxime. The genetic environment of bla NDM-13 was determined to be tnpA-IS30-bla NDM-13-ble MBL-trpF-dsbC-cutA-groES-groL, with bla NDM-13 located within the chromosome.

NDM-12, a novel New Delhi metallo-ß-lactamase variant from a carbapenem-resistant Escherichia coli clinical isolate in Nepal.

A novel New Delhi metallo-ß-lactamase variant, NDM-12, was identified in a carbapenem-resistant Escherichia coli clinical isolate obtained from a urine sample from a patient in Nepal. NDM-12 differed from NDM-1 by two amino acid substitutions (M154L and G222D). The enzymatic activities of NDM-12 against ß-lactams were similar to those of NDM-1, although NDM-12 showed lower kcat/Km ratios for all ß-lactams tested except doripenem. The blaNDM-12 gene was located in a plasmid of 160 kb.

Has Data Quality of an Antimicrobial Resistance Surveillance System in a Province of Nepal Improved between 2019 and 2022?

An operational research study was conducted in 2019 to assess the quality of data submitted by antimicrobial resistance (AMR) surveillance sites in the Bagmati Province of Nepal to the National Public Health Laboratory for Global Antimicrobial Resistance and Use Surveillance System (GLASS). Measures were implemented to enhance the quality of AMR surveillance by strengthening capacity, improving infrastructure, implementing data sharing guidelines, and supervision. The current study examined reports submitted by surveillance sites in the same province in 2022 to assess whether the data quality had improved since 2019. The availability of infrastructure at the sites was assessed. Of the nine surveillance sites in the province, seven submitted reports in 2022 versus five in 2019. Completeness in reporting improved significantly from 19% in 2019 to 100% in 2022 (p < 0.001). Timely reports were received from two sites in 2019 and only one site in 2022. Specimen-pathogen consistency in accordance with the GLASS guidelines for urine, feces, and genital swab specimens improved, with ≥90% consistency at all sites. Overall, the pathogen-antibacterial consistency improved significantly for each GLASS priority pathogen. The study highlights the importance of dedicated infrastructure and institutional arrangements for AMR surveillance. Similar assessments covering all provinces of the country can provide a more complete country-wide picture.

Lower Susceptibility to Fluoroquinolones and a gyrA Gene Mutation in Salmonella Typhi Isolates from Enteric Fever Patients.

BACKGROUND: Enteric fever remains a major cause of morbidity and mortality in Nepal. The emergence of multi-drug resistant Salmonella is a challenge to the clinician to care for patients with enteric fever. This study assessed the antibiotic susceptibility of Salmonella Typhi isolated from enteric fever and the presence of gyrA? ?gene mutation at ser83 of S. Typhi. METHODS: Blood samples (n = 834) from suspected enteric fever patients were collected and cultured to identify Salmonella Typhi. Antimicrobial sensitivity test was performed by the modified Kirby Bauer disc diffusion method. The minimum ?inhibitory concentration (MIC) tests for ofloxacin and ciprofloxacin were examined by the agar dilution method. The gyrA gene was amplified by PCR and restriction enzyme digestion was performed to evaluate the ser83 mutation. RESULTS: Among 824 blood samples analyzed, 5.1% (42/824) were culture positive for S. Typhi. First-line antibiotics chloramphenicol and co-trimoxazole showed higher in-vitro efficacy compared to amoxicillin. Macrolides (azithromycin) and third-generation cephalosporins (ceftriaxone, cefixime, and cefotaxime) were highly effective against S. Typhi. Nalidixic acid resistance (NAR) was observed in 95.2% (40/42) isolates, among them, all (40/40) isolates harbored mutant gyrA gene at ser83. However, none of the nalidixic acid-sensitive Salmonella? isolates was positive for gyrA? mutation at ser83. CONCLUSIONS: This study showed decreased susceptibility to fluoroquinolones and the presence of gyrA? mutation at ser83 position in majority of S. Typhi isolates which highlights the importance of alternate drugs as empirical therapy for the treatment of enteric fever patients. So, the clinician should focus on prescribing conventional first-line antibiotics for the treatment of typhoid patients after higher cohort and extended follow-up studies.

Detection of NDM Variants (bla NDM-1, bla NDM-2, bla NDM-3) from Carbapenem-Resistant Escherichia coli and Klebsiella pneumoniae: First Report from Nepal.

Background: Increasing burden of carbapenem resistance among Enterobacterales is attributable to their ability to produce carbapenemase enzymes like metallo-beta-lactamase (MBL), Klebsiella pneumoniae carbapenemase (KPC), and OXA-type. This study aimed to determine the prevalence of carbapenemases and MBL genes ((bla NDM-1, bla NDM-1 and bla NDM-3) among E. coli and K. pneumoniae isolates. Methods: A total of 2474 urine samples collected during the study period (July-December 2017) were processed at the microbiology laboratory of Kathmandu Model Hospital, Kathmandu. Isolates of E. coli and K. pneumoniae were processed for antimicrobial susceptibility testing (AST) by disc diffusion method. Carbapenem-resistant isolates were subjected to Modified Hodge Test (MHT) for phenotypic confirmation, and inhibitor-based combined disc tests for the differentiation of carbapenemase (MBL and KPC). MBL-producing isolates were screened for NDM genes by polymerase chain reaction (PCR). Results: Of the total urine samples processed, 19.5% (483/2474) showed the bacterial growth. E. coli (72.6%; 351/483) was the predominant isolate followed by K. pneumoniae (12.6%; 61/483). In AST, 4.4% (18/412) isolates of E. coli (15/351) and K. pneumonia (3/61) showed resistance towards carbapenems, while 1.7% (7/412) of the isolates was confirmed as carbapenem-resistant in MHT. In this study, all (3/3) the isolates of K. pneumoniae were KPC-producers, whereas 66.7% (10/15), 20% (3/15) and 13.3% (2/15) of the E. coli isolates were MBL, KPC and MBL/KPC (both)-producers, respectively. In PCR assay, 80% (8/10), 90% (9/10) and 100% (10/10) of the isolates were positive for bla NDM-1, bla NDM-2 and bla NDM-3, respectively. Conclusion: Presence of NDM genes among carbapenemase-producing isolates is indicative of potential spread of drug-resistant variants. This study recommends the implementation of molecular diagnostic facilities in clinical settings for proper infection control, which can optimize the treatment therapies, and curb the emergence and spread of drug-resistant pathogens.

Antimicrobial Resistance in Salmonella Typhi Isolated From a Referral Hospital of Kathmandu, Nepal.

PURPOSE: The morbidity and mortality due to typhoid fever can be significantly reduced with the use of effective antibiotics. At present, fluoroquinolones, third generation cephalosporins, and azithromycin are widely used to treat typhoid fever. However, changing antibiotic susceptibility among Salmonella Typhi and Salmonella Paratyphi poses a particular challenge to the therapeutic management of enteric fever. The objective of this study was to assess the antibiotic susceptibility pattern of Salmonella Typhi isolates. PATIENTS AND METHODS: A total of 706 blood specimens were collected from febrile patients attending the outpatient department of Kathmandu Model Hospital during June to September, 2018. The antibiotic susceptibility testing for 11 different antibiotics (nalidixic acid, ciprofloxacin, ofloxacin, levofloxacin, cefixime, ceftriaxone, cefotaxime, azithromycin, cotrimoxazole, chloramphenicol, and amoxicillin) was performed by disk diffusion method. Furthermore, minimum inhibitory concentration (MIC) values of ciprofloxacin, ofloxacin, and azithromycin were determined by agar dilution method. Mutation at gyrA ser83 associated with reduced susceptibility to fluoroquinolones was determined by PCR-RFLP. RESULTS: Out of 706 blood samples, 6.94% (n = 49) were culture positive for Salmonella enterica (S. Typhi, n = 46). It was revealed that 97.8% S. Typhi isolates were susceptible to conventional first-line antibiotics (ampicillin, chloramphenicol, and cotrimoxazole), 97.3% to cephalosporins and 95.7% to azithromycin. S. Typhi were either resistant or intermediately susceptible to fluoroquinolones: 97.8% to ciprofloxacin, 91.3% to ofloxacin, and 89.1% to levofloxacin. The MIC of ciprofloxacin, ofloxacin, and azithromycin for S. Typhi ranged from 0.008 to 32, 0.03 to 16, and 2 to 8 µg/mL, respectively. Out of 46 S. Typhi isolates, 44 (95.65%) had gyrA ser83 mutation. CONCLUSION: Fluoroquinolones have poor activity against Salmonella Typhi. The trends of increasing azithromycin MIC value among S. Typhi might limit its use for the treatment of typhoid fever. Effectiveness of conventional first-line antibiotics in vitro suggests considering their clinical use after large-scale studies.

Antibiotic resistance and detection of plasmid mediated colistin resistance mcr-1 gene among Escherichia coli and Klebsiella pneumoniae isolated from clinical samples.

BACKGROUND: The prevalence of antimicrobial resistance (AMR) among Gram-negative bacteria is alarmingly high. Reintroduction of colistin as last resort treatment in the infections caused by drug-resistant Gram-negative bacteria has led to the emergence and spread of colistin resistance. This study was designed to determine the prevalence of drug-resistance among beta-lactamase-producing strains of Escherichia coli and Klebsiella pneumoniae, isolated from the clinical specimens received at a tertiary care centre of Kathmandu, Nepal during the period of March to August, 2019. METHODS: A total of 3216 different clinical samples were processed in the Microbiology laboratory of Kathmandu Model Hospital. Gram-negative isolates (E. coli and K. pneumoniae) were processed for antimicrobial susceptibility test (AST) by using modified Kirby-Bauer disc diffusion method. Drug-resistant isolates were further screened for extended-spectrum beta-lactamase (ESBL), metallo-beta-lactamase (MBL), carbapenemase and K. pneumoniae carbapenemase (KPC) production tests. All the suspected enzyme producers were processed for phenotypic confirmatory tests. Colistin resistance was determined by minimum inhibitory concentration (MIC) using agar dilution method. Colistin resistant strains were further screened for plasmid-mediated mcr-1 gene using conventional polymerase chain reaction (PCR). RESULTS: Among the total samples processed, 16.4% (529/3216) samples had bacterial growth. A total of 583 bacterial isolates were recovered from 529 clinical samples. Among the total isolates, 78.0% (455/583) isolates were Gram-negative bacteria. The most predominant isolate among Gram-negatives was E. coli (66.4%; 302/455) and K. pneumoniae isolates were 9% (41/455). In AST, colistin, polymyxin B and tigecycline were the most effective antibiotics. The overall prevalence of multidrug-resistance (MDR) among both of the isolates was 58.0% (199/343). In the ESBL testing, 41.1% (n = 141) isolates were confirmed as ESBL-producers. The prevalence of ESBL-producing E. coli was 43% (130/302) whereas that of K. pneumoniae was 26.8% (11/41). Similarly, 12.5% (43/343) of the total isolates, 10.9% (33/302) of E. coli and 24.3% of (10/41) K. pneumoniae were resistant to carbapenem. Among 43 carbapenem resistant isolates, 30.2% (13/43) and 60.5% (26/43) were KPC and MBL-producers respectively. KPC-producers isolates of E. coli and K. pneumoniae were 33.3% (11/33) and 20% (2/10) respectively. Similarly, 63.6% (21/33) of the E. coli and 50% (5/10) of the K. pneumoniae were MBL-producers. In MIC assay, 2.2% (4/179) of E. coli and 10% (2/20) of K. pneumoniae isolates were confirmed as colistin resistant (MIC ≥ 4 µg/ml). Overall, the prevalence of colistin resistance was 3.1% (6/199) and acquisition of mcr-1 was 16.6% (3/18) among the E. coli isolates. CONCLUSION: High prevalence of drug-resistance in our study is indicative of a deteriorating situation of AMR. Moreover, significant prevalence of resistant enzymes in our study reinforces their roles in the emergence of drug resistance. Resistance to last resort drug (colistin) and the isolation of mcr-1 indicate further urgency in infection management. Therefore, extensive surveillance, formulation and implementation of effective policies, augmentation of diagnostic facilities and incorporation of antibiotic stewardship programs can be some remedies to cope with this global crisis.

Higher Prevalence of Extended Spectrum ß-Lactamase Producing Uropathogenic Escherichia coli Among Patients with Diabetes from a Tertiary Care Hospital of Kathmandu, Nepal.

This study aimed to determine the occurrence of antibiotic resistance genes for ß-lactamases; blaTEM and blaCTX-M in uropathogenic Escherichia coli isolates from urinary tract infection (UTI) suspected diabetic and nondiabetic patients. A hospital-based cross-sectional study was conducted in Kathmandu Model Hospital, Kathmandu, in association with the Department of Microbiology, GoldenGate International College, Kathmandu, Nepal, from June to December 2018. A total of 1,267 nonduplicate midstream urine specimens were obtained and processed immediately for isolation of uropathogens. The isolates were subjected to antibiotic susceptibility testing and extended spectrum ß-lactamase (ESBL) confirmation. In addition, blaTEM and blaCTX-M genes were detected using specific primers. The overall prevalence of UTI was 17.2% (218/1,267), of which patients with diabetes were significantly more infected; 32.3% (31/96) as compared with nonpatients with diabetes, 15.9% (187/1,171). A total of 221 bacterial isolates were obtained from 218 culture-positive specimens in which E. coli was the most predominant; 67.9% (150/221). Forty-four percent (66/150) of the total E. coli was multidrug resistant and 37.3% (56/150) were ESBL producers. Among 56 isolates, 92.3% (12/13) were from patients with diabetes, and 83.0% (44/53) were from nondiabetics. Furthermore, 84.9% of the screened ESBL producers were confirmed to possess either single or both of blaTEM and blaCTX-M genes. The blaTEM and blaCTX-M genes were detected in 53.6% and 87.5% of the phenotypically ESBL confirmed E. coli, respectively. Higher rates of ESBL producing uropathogenic E. coli are associated among patients with diabetes causing an alarming situation for disease management. However, second-line drugs with broad antimicrobial properties are still found to be effective drugs for multidrug resistance strains.

Antimicrobial Resistance in Typhoidal Salmonella in Nepal: Surveillance for Enteric Fever, 2016-2019.

BACKGROUND: Enteric fever (caused by Salmonella enterica) has been associated with poor hygiene and is endemic in the South-Asian countries. The increase in resistance to first line antimicrobials has been observed, while the emergence of multi/extremely drug resistance cases have been identified in several countries. The objective of this study is to analyze the current trend of antimicrobial resistance in Salmonella isolates in Nepal, and to identify the status of multi- and extremely- drug resistant isolates. METHODS: We recruited individuals at study hospitals with suspected enteric fever between September 2016 and August 2019 and performed blood cultures. The Salmonella isolates were tested for antimicrobial susceptibility and the antimicrobial resistance trend was evaluated. RESULTS: 1438 positive blood culture isolates were studied for antimicrobial resistance. 88% were culture positive for Salmonella Typhi and 12% for Salmonella Paratyphi. Multidrug resistant S. Typhi cases appeared mostly in December 2018 and January 2019, while there were no multidrug resistant S. Paratyphi cases. Also, extremely drug resistant S. Typhi cases were not observed during the study period. CONCLUSIONS: The Salmonella isolates were mostly susceptible to first-line antimicrobials, cephalosporins and others. Many fluoroquinolones non-susceptible Salmonella were obtained, nevertheless their overall trend seems to be declining. In addition, the S. Paratyphi total cases are reducing since September 2017. Among S. Typhi isolates, only few were multidrug resistant and there were no extremely drug resistant isolates.

Quality Assessment of an Antimicrobial Resistance Surveillance System in a Province of Nepal.

Antimicrobial resistance (AMR) is a global problem, and Nepal is no exception. Countries are expected to report annually to the World Health Organization on their AMR surveillance progress through a Global Antimicrobial Resistance Surveillance System, in which Nepal enrolled in 2017. We assessed the quality of AMR surveillance data during 2019-2020 at nine surveillance sites in Province 3 of Nepal for completeness, consistency, and timeliness and examined barriers for non-reporting sites. Here, we present the results of this cross-sectional descriptive study of secondary AMR data from five reporting sites and barriers identified through a structured questionnaire completed by representatives at the five reporting and four non-reporting sites. Among the 1584 records from the reporting sites assessed for consistency and completeness, 77-92% were consistent and 88-100% were complete, with inter-site variation. Data from two sites were received by the 15th day of the following month, whereas receipt was delayed by a mean of 175 days at three other sites. All four non-reporting sites lacked dedicated data personnel, and two lacked computers. The AMR surveillance data collection process needs improvement in completeness, consistency, and timeliness. Non-reporting sites need support to meet the specific requirements for data compilation and sharing.

Plasmid Profiling and Occurrence of ß-Lactamase Enzymes in Multidrug-Resistant Uropathogenic Escherichia coli in Kathmandu, Nepal.

INTRODUCTION: Extended-spectrum ß-lactamases (ESBL) among Gram-negative bacteria, predominantly Escherichia coli (E. coli), in Nepal, have been rising. The main objectives of this study were to determine the prevalence of uropathogenic E. coli, antibiotic resistance, ESBLs, ABLs (AmpC type ß-lactamases), MBLs (metallo-ß-lactamases) and KPCs (Klebsiella pneumoniae carbapenemases) and their correlation with plasmid profiling patterns among patients with urinary tract infections in a tertiary hospital in Kathmandu, Nepal. METHODS: The mid-stream urine samples collected from patients were inoculated in cystine-lactose-electrolyte-deficient (CLED) agar plates. E. coli producing ESBLs, ABLs, MBLs/KPC were identified phenotypically using standard microbiological methods. Plasmids were extracted by alkaline lysis method from E. coli isolates and profiled using agarose gel electrophoresis. RESULTS: Out of the total 2661 urine samples, E. coli were isolated in 64.34% (507/788), among which 170 (33.53%) were multidrug-resistant (MDR) isolates. All MDR isolates were resistant to amoxicillin and third-generation cephalosporins but were highly sensitive to imipenem (94.12%, 160/170), amikacin (92.94%, 158/170) and nitrofurantoin (86.47%, 147/170). Among 170 MDR isolates, 78.2% (133/170) were ESBLs, 46.3% (50/170) were AmpC, 11.2% (19/170) were MBL and 0.6% (1/170) were KPC producers. Coproduction of ß-lactamases was detected in 24.12% (41/170) of isolates. E. coli isolates showed one plasmid (>33.5 kb), which was present in all the isolates. Overall, 44 different plasmid profile groups were identified based on molecular weight and number of plasmids. ß-Lactamase producers were relatively resistant to the higher number of antibiotics tested (≤10) than non-producers (≤8), and the number of plasmids were higher in ß-lactamase producers (≤7) than those in non-producers (≤5). CONCLUSION: The higher prevalence of the ESBLs, AmpCs, KPCs and MBLs along with their coproduction in E. coli isolates highlights the importance of routine surveillance of ESBLs, AmpCs, KPCs and MBLs in microbiology laboratories using various phenotypic methods.

Evaluation of an Antimicrobial Stewardship Program for Wound and Burn Care in Three Hospitals in Nepal.

Antimicrobial stewardship (AMS) programs can decrease non-optimal use of antibiotics in hospital settings. There are limited data on AMS programs in burn and chronic wound centers in low- and middle-income countries (LMIC). A post-prescription review and feedback (PPRF) program was implemented in three hospitals in Nepal with a focus on wound and burn care. A total of 241 baseline and 236 post-intervention patient chart data were collected from three hospitals. There was a significant decrease in utilizing days of therapy per 1000 patient days (DOT/1000 PD) of penicillin (p = 0.02), aminoglycoside (p < 0.001), and cephalosporin (p = 0.04). Increases in DOT/1000 PD at post-intervention were significant for metronidazole (p < 0.001), quinolone (p = 0.01), and other antibiotics (p < 0.001). Changes in use of antibiotics varied across hospitals, e.g., cephalosporin use decreased significantly at Kirtipur Hospital (p < 0.001) and Pokhara Academy of Health Sciences (p = 0.02), but not at Kathmandu Model Hospital (p = 0.59). An independent review conducted by infectious disease specialists at the Henry Ford Health System revealed significant changes in antibiotic prescribing practices both overall and by hospital. There was a decrease in mean number of intravenous antibiotic days between baseline (10.1 (SD 8.8)) and post-intervention (8.8 (SD 6.5)) (t = 3.56; p < 0.001), but no difference for oral antibiotics. Compared to baseline, over the 6-month post-intervention period, we found an increase in justified use of antibiotics (p < 0.001), de-escalation (p < 0.001), accurate documentation (p < 0.001), and adherence to the study antibiotic prescribing guidelines at 72 h (p < 0.001) and after diagnoses (p < 0.001). The evaluation data presented provide evidence that PPRF training and program implementation can contribute to hospital-based antibiotic stewardship for wound and burn care in Nepal.

The Bacteriological Profile of Burn Wound Infections at a Tertiary Burns Center in Nepal.

In Nepal, burn is the third most common injury after falls and road traffic accidents. Infection is the leading cause of mortality in burn injury. A profile exploring predominant flora and antimicrobial sensitivity is important to facilitate treatment ahead of microbiology results and to aid prevention of multidrug-resistant organisms. The aim of this study was to document epidemiological and bacteriological data of burn wound infections at a tertiary level burns center in Nepal. Samples were collected from January 2017 to May 2017, over a period of 5 months. Patient notes were referred to and information regarding baseline characteristics and burn wound infection data was collected. A total of 76 patients were included in the study during the 5-month period, which resulted in 113 samples being included for review. Females were injured most with burns 70% (n = 53) compared with males 30% (n = 23). Only 6 (8%) of 77 patients lived locally in Kathmandu. The average distance traveled by patients was 233 km (median 208, range 0-765, SD 181). Average TBSA% of burn was 22% (median 20, range 3-50, SD 12). Gram-negative organisms predominated, with Acinetobacter spp. in 42 cases (55%), Pseudomonas aeruginosa in 26 cases (34%), and Enterobacter spp. in 16 cases (21%). Colistin, polymyxin B, and tigecycline were found to be most sensitive covering 108, 98, and 94 organisms. Gram-negative bacteria colonized the majority of burn wounds. Colistin, polymyxin B, and tigecycline were the most sensitive to gram-negative bacteria. Gram-positive Staphylococcus aureus was sensitive most to vancomycin and tigecycline.

Evaluation of a Hospital-Based Post-Prescription Review and Feedback Pilot in Kathmandu, Nepal.

Capacity building is needed in low- and middle-income countries (LMICs) to combat antimicrobial resistance (AMR). Stewardship programs such as post-prescription review and feedback (PPRF) are important components in addressing AMR. Little data are available regarding effectiveness of PPRF programs in LMIC settings. An adapted PPRF program was implemented in the medicine, surgery, and obstetrics/gynecology wards in a 125-bed hospital in Kathmandu. Seven "physician champions" were trained. Baseline and post-intervention patient chart data were analyzed for changes in days of therapy (DOT) and mean number of course days for intravenous and oral antibiotics, and for specific study antibiotics. Charts were independently reviewed to determine justification for prescribed antibiotics. Physician champions documented recommendations. Days of therapy per 1,000 patient-days for courses of aminoglycoside (P < 0.001) and cephalosporin (P < 0.001) decreased. In the medicine ward, data indicate increased justified use of antibiotics (P = 0.02), de-escalation (P < 0.001), rational use of antibiotics (P < 0.01), and conforming to guidelines in the first 72 hours (P = 0.02), and for definitive therapy (P < 0.001). Physician champions documented 437 patient chart reviews and made 138 recommendations; 78.3% of recommendations were followed by the attending physician. Post-prescription review and feedback can be successfully implemented in LMIC hospitals, which often lack infectious disease specialists. Future program adaptation and training will focus on identifying additional stewardship programming and support mechanisms to optimize antibiotic use in LMICs.

Antimicrobial Sensitivity Trend in Blood Culture Positive Enteric Fever.

BACKGROUND: For diagnosis of enteric fever, the culture of the organism from different body fluids is the gold standard. After diagnosis, it is important to treat with the right antibiotic before any complications can occur. The retrospective study is designed to explore the antibiotic sensitivity trend in blood culture positive typhoid fever cases and the extent of drug resistance before treatment is administered. METHODS: A retrospective study was carried out for culture isolated enteric fever patients admitted in Kathmandu Model Hospital. The discharged records from January 2012 to December 2016 were analyzed. The patients above 15 years and with culture isolated enteric fever were included in the study. RESULTS: One hundred fifty-nine strains of Salmonella typhi and paratyphi were isolated from Jan 2012 to Dec 2016 at Kathmandu Model Hospital. Out of 159 isolated, 125 (78.6%) were Salmonella typhi and 34 (21.4%) were paratyphi. Among them co-trimoxazole, chloramphenicol, ceftriaxone, cefotaxime, cefixime, and ofloxacin demonstrated 100% sensitivity. Similarly, amoxicillin sensitivity was 98.1% (n=156) while ciprofloxacin was sensitive in 6.3% (n=10), intermediately sensitive in 49.1% (n=78) and resistance in 44.7% (n=71).The newer quinolone levofloxacin showed 78.5% (n=11) sensitivity. Azithromycin was sensitive in 99.2% (n=132) of total isolated Salmonella species both typhi and paratyphi. CONCLUSIONS: A high degree of sensitivity was noted to chloramphenicol and co-trimoxazole, showing sensitivity has returned to conventional antibiotics. The drug-like ofloxacin is still the best responding drug in our contest whereas ciprofloxacin resistance is still high, but five years patterns show a trend of rollback of sensitivity.

Antibiotic Susceptibility Pattern of Gram-negative Isolates of Lower Respiratory Tract Infection.

BACKGROUND: Lower respiratory tract infection is a common cause of morbidity and mortality worldwide. A cross-sectional study was carried out with an objective to study the antibiogram of Gram-negative isolates of patients with lower respiratory tract infection visiting Kathmandu Model Hospital. METHODS: A total of 274 specimens including sputum, endotracheal aspirates, suction tips were cultured as per standard microbiological technique. Antibiotic susceptibility and detection of Extended-spectrum beta- lactamases (ESBLs) were performed following Clinical Laboratory Standard Institute (CLSI 2014) guidelines. RESULTS: Respiratory pathogens were recovered from 24.6% (n=65) cases. Klebsiella pneumoniae (40%) was the commonest isolates. The highest prevalence of multidrug-resistance (69.23%) was observed in Acinetobacter calcoaceticus baumannii complex. Extended-spectrum beta- lactamases were detected in Escherichia coli (n=4), Klebsiella pneumoniae (n=4) and Acinetobacter calcoaceticus baumannii complex (n=1). CONCLUSIONS: High prevalence of multidrug-resistance and extended- spectrum beta- lactamase producers were observed in respiratory isolates. For effective management of lower respiratory tract infections, an ultimate and detailed microbiological diagnosis and susceptibility testing is required.

Re-emergence of the susceptibility of the Salmonella spp. isolated from blood samples to conventional first line antibiotics.

BACKGROUND: Enteric 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. METHODS: A 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. RESULTS: Of 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. CONCLUSION: The 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.

Clinical and microbiological observational study on AmpC ß-lactamase-producing Enterobacteriaceae in a hospital of Nepal.

Limited information is available regarding AmpC ß-lactamase (ABL)-producing Enterobacteriaceae compared to extended-spectrum ß-lactamase-producing enterobacteria. Since ABL-producing organisms are often resistant to multiple antimicrobial agents, therapeutic options against these pathogens are limited. Among 230 clinical Enterobacteriaceae isolates, 64 (27.8%) were found to produce ABL in our study. Escherichia coli (83.9%) was a predominant pathogen, followed by Citrobacter freundii (5.2%). A significant proportion of ABL-producing isolates (81.3%) were found to be multidrug resistant against commonly used antibiotics. Univariate analysis showed that prior history of taking antibiotics (odds ratio [OR], 5.278; confidence interval [CI], 2.838-9.817; p<0.001) and being inpatients (OR, 4.587; CI, 2.132-9.9; p<0.001) were associated with ABL positivity. Regular antimicrobial resistance surveillance for ABL-producing Enterobacteriaceae is warranted for proper antimicrobial treatment strategy and policy making due to ABL-positive infections.

High prevalence of multidrug resistance in bacterial uropathogens from Kathmandu, Nepal.

BACKGROUND: Urinary 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). RESULTS: Two 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 ß-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. CONCLUSIONS: The 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.