Background Staphylococcus aureus is a cardinal source of community- and hospital-acquired infection. HIV infection is a well-recognized risk factor for methicillin-resistant S. aureus (MRSA) carriage and infection. Intrinsically developed antibiotic resistance has sharply increased the burden of MRSA which is often associated with morbidity and mortality of the patients. Moreover, nasal carriage of S. aureus plays a significant role in spread of community-associated (CA) S. aureus infections. Methods This study was conducted from June 2016 to December 2016 at National Public Health Laboratory (NPHL), Kathmandu, with an aim to assess the rate of S. aureus nasal carriage and MRSA carriage among HIV-infected and non-HIV patients. A total of 600 nonrepeated nasal swabs were analyzed following standard microbiological procedures, where 300 swabs were from HIV-infected patients while remaining 300 were from non-HIV patients. The isolates were identified on the basis of colony characteristics and a series of biochemical tests. The antibiotic susceptibility test (AST) was performed by the modified Kirby–Bauer disc diffusion method. Inducible clindamycin resistance in isolates was confirmed by the D-test method. Results Overall, out of 600 nasal swabs of patients tested, 125 (20.8%) were S. aureus nasal carriers which included 80 out of 300 (26.66%) among HIV-infected patients and 45 (15%) out of 300 among non-HIV patients, and the result was statistically significant (p=0.0043). Among the isolated S. aureus, 11 (13.8%) MRSA were confirmed in HIV-infected while 3 (6.7%) MRSA were detected from non-HIV patients. A higher number of S. aureus carriers was detected among HIV-infected males 40 (26.49%), whereas MRSA carriage was more prevalent among HIV-infected females 7 (5.1%). Among the HIV-infected, patients of age group 31–40 years were the ones with highest carriage rate 36 (45%), while in non-HIV patients, the highest rate 13 (28.9%) of carriage was detected among the patients of age group 21–30 years. Statistically significant difference was found between S. aureus carriage and HIV infection in patients (p < 0.05). Higher rate 2/3 (66.7%) of inducible clindamycin resistance in MRSA was detected from non-HIV patients in comparison to HIV-infected patients 7/11 (63.63%) while the result was statistically insignificant (p > 0.05). All the MRSA isolates (100%) were resistant against co-trimoxazole while ciprofloxacin showed high rate of sensitivity towards both MSSA and MRSA. None of the isolates were detected as VRSA. The major factors associated with nasal colonization of S. aureus were close personal contact, current smoking habit, and working or living in a farm (p < 0.05). Conclusion Regular surveillance and monitoring of MRSA nasal carriage and antibiotic susceptibility pattern are of prime importance in controlling S. aureus infections especially in high risk groups like HIV-infected patients.

Background: Pseudomonas aeruginosa is an opportunistic human pathogen and are reported to cause acute and chronic infectious diseases. Due to its high ability to acquire resistance to many antibiotics, it has become a global public health threat. It consists of some virulence genes that may lead to its pathogenicity. The main objective of this cross-sectional study was to detect the virulence genes and antibiotic susceptibility pattern of P. aeruginosa isolated from clinical specimens collected from governmental hospital of Nepal.Methods: A total of 7898 clinical specimens were analyzed for the period of six months from November 2018 to April 2019. The specimens were cultured on Nutrient agar, Blood agar, MacConkey agar, Chocolate agar, Cysteine-Lactose, Electrolyte Deficient agar plates and were incubated at 37°C for 24 hours. All the isolates were identified by standard biochemical tests and further confirmed by growth on Cetrimide agar plate. The antibiotic susceptibility testing was performed by modified Kirby-Bauer disc diffusion method following CLSI guideline. Multiplex-PCR was done to detect the virulence genes oprL and toxA. Statistical analysis was carried out using IBM SPSS Statistic ver. 25 and the p-value was calculated at significance level (0.05%) by using Chi square.Results: Out of these specimens investigated, 87 isolates were tentatively identified to be P. aeruginosa in which 20 (22.98 %) were found to be multidrug resistant. Comparatively, most of the P. aeruginosa were isolated from outpatients 63 (72.41 %) than inpatients 24 (27.58 %), from male 56 (64.36 %) than female 31 (35.63 %) and in age group 60-79 years (41.37 %). AST result showed the highest resistance of 100% with cefixime whereas susceptibilities of 83.9% and 81.6% with polymixin B and tobramycin were noticed respectively. The PCR results showed that all P. aeruginosa isolates carried oprL 87 (100%) and 83 (95.4 %) isolates showed toxA genes. Conclusion: The studies revealed that almost all P. aeruginosa harbors both oprL and toxA genes.

The multidrug- or extensively drug-resistant (MDR/XDR) Pseudomonas aeruginosa carrying some virulence genes has become a global public health threat. However, in Nepal, there is no existing report showing the prevalence of oprL and toxA virulence genes among the clinical isolates of P. aeruginosa. Therefore, this study was conducted for the first time in the country to detect the virulence genes (oprL and toxA) and antibiotic susceptibility pattern of P. aeruginosa. A total of 7,898 clinical specimens were investigated following the standard microbiological procedures. The antibiotic susceptibility testing was examined by the modified disc diffusion method, and virulence genes oprL and toxA of P. aeruginosa were assessed using multiplex PCR. Among the analyzed specimens, 87 isolates were identified to be P. aeruginosa of which 38 (43.68%) isolates were reported as MDR. A higher ratio of P. aeruginosa was detected from urine samples 40 (45.98%), outpatients’ specimens 63 (72.4%), and in patients of the age group of 60–79 years 36 (41.37%). P. aeruginosa was more prevalent in males 56 (64.36%) than in female patients 31 (35.63%). Polymyxin (83.90%) was the most effective antibiotic. P. aeruginosa (100%) isolates harboured the oprL gene, while 95.4% of isolates were positive for the toxA gene. Identification of virulence genes such as oprL and toxA carrying isolates along with the multidrug resistance warrants the need for strategic interventions to prevent the emergence and spread of antimicrobial resistance (AMR). The findings could assist in increasing awareness about antibiotic resistance and suggest the judicious prescription of antibiotics to treat the patients in clinical settings of Nepal.

The chemokine receptor CCR5 exhibits an important role for the CD-4 mediated entry of HIV-1. Previous studies revealed that Δ32 mutation on the CCR5 gene results in truncated protein and hence confers protection against HIV-1 infection and AIDS progression, as observed in Caucasian population. However, the status of Δ32 mutation on CCR5 is still unknown in many Nepali ethnic groups though detection of heterozygous CCR5 Δ32 mutation allele has been reported from Chidimar and Thakali ethnic groups. We studied the presence of the Δ32 mutation in 300 blood samples from 11 ethnic groups of Nepal by analyzing PCR product of CCR5 gene region flanking the Δ32 mutation region. The primer set (forward -5’ CTC CCA GGA ATC ATC TTT ACC 3’ and reverse - 5’ TCA TTT CGA CAC CGA AGC AG 3’) flanks the site of the Δ32 deletion region of CCR5 gene. This results in a PCR fragment of 200 base pairs for the CCR5 wild allele and 168 base pairs for a Δ32 deletion mutation allele. All samples were found to exhibit wild type CCR5 gene; but no Δ32 mutation observed. Absence of Δ32 mutation in CCR5 gene indicates that Nepali population is not genetically resistant to HIV infection, if other genes are not considered.

Extended Spectrum Beta Lactamases (ESBL), the main cause of resistance to broad spectrum β-lactams, among uropathogenic bacteria have increased over time raising a global concern in the therapeutic management of infections caused by these organisms. The study was carried out in Janamaitri Hospital, Kathmandu between December 2012 to May 2013 with an objective to determine the status of ESBL producing Gram negative bacilli isolated from the urine sample, collected from patients suspected of urinary tract infection. Gram negative bacilli isolated were tested for the presence of ESBL by combined disk and antibiotic susceptibility by Kirby Bauer disc diffusion method following Clinical and Laboratory Standard Institute guidelines. Among the total 1105 mid-stream urine samples, 256 Gram negative bacilli were isolated. By screening test using third generation cephalosporins, 156 isolates were screened as ESBL producers and 91 isolates were positive for ESBL test by combined disk method. Among the 91 (35.55%) ESBL producers, 70 (39.32%) Escherichia coli, 16 (44.44%) Klebsiella pneumoniae, and 5 (33.33%) Pseudomonas aeruginosa were found to be ESBL producers. Majority of ESBL producer showed resistance to ampicillin, co-trimoxazole, norfloxacin followed by ofloxacin. imipenem, amikacin and nitrofurantoin seemed to be the agent of choice for urinary tract infections when ESBL producers are susceptible to it. ESBL production found in these Gram negative bacilli with resultant microbial resistance to available cephalosporins and other agents may pose difficulties with the choice of therapeutic options for the treatment of severe infections.