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Objectives: To determine the antimicrobial activity of silver nano-particles(AgNPs) with tetracycline and ampicillin against multi-drug resistance (MDR) and extensively-drug resistance (XDR) Salmonella typhi ., Methods: Cross sectional non-probability purposive study was conducted from September, 2021 to May, 2022 at Microbiology department PNS Shifa, Hospital Karachi. Blood cultures of patients suspicious of typhoid fever were collected and incubated in automated Bact/Alert system. Positive cultures were identified on blood and MacConkey and processed by API-10S, confirmed by serotyping (O9 antisera) (SSI Diagnostica's Salmonella) . Antibiotic resistance was done by Kirby-Bauer disk diffusion (Sigma and Rich). MDR and XDR isolates were preserved in Brain Heart Infusion in a volume of 2ml in screw capped bottles at -70°C. Antimicrobial powders (ampicillin and tetracycline (Alfa Aesar) weighed by an electrical weighing balance (OHAUS) to take 1mg of antimicrobial drug. Absorbance spectra of serial concentrations of antibiotics (UV-Vis spectrophotometer (Mole-Qule-) AgNPs (10nm) (nanocomposix) + Antibiotic in (1:1 volume ratio). Conjugation of silver nanoparticles with tetracycline and ampicillin was done by FTIR (thermos scientificThermos ScientificNicolet 50)., Results: Out of 77 isolates, 54 were resistant to ceftriaxone (XDR) and 23 sensitive to ceftriaxone (MDR). All isolates were susceptible to azithromycin and meropenem. Comparison of zone of inhibitions of ampicillin and Amp-AgNPsas and tetracycline with Tet-AgNPs was done. Minimal inhibitory concentration was also done to determine antimicrobial activity., Conclusion: Significant synergistic inhibitory effects against Salmonella Typhi isolates were obtained by combination of tetracycline with silver nano-particles even at low concentration., (Copyright: © Pakistan Journal of Medical Sciences.)

Objective: To determine blaCTX-M-15(Cefotaxime-Munich) gene amongst the extensively drug resistant (XDR) Salmonella typhi (S. typhi) isolates by quantitative Polymerase Chain Reaction (qPCR)., Study Design: Observational, cross-sectional study. Place and Duration of the Study: PNS Shifa Hospital and Bahria University of Health Sciences (BUHS), from January to June 2022., Methodology: All the patients clinically suspected of enteric fever, whose blood culture specimens yielded growth of S. typhi were included in this study. These samples were confirmed by serotyping and biochemical reactions. The ceftriaxone resistance was evaluated by antibiotic susceptibility test according to CLSI 2020 guidelines, whereas blaCTX-M-15 gene was detected by (PCR) using gene-specific primers., Results: Out of 149 S. typhi isolates, 87.2% were confirmed XDR S. typhi resistant to ceftriaxone (CRO). Among these, 83.9% harboured blaCTX-M-15 gene., Conclusion: There was a very high frequency of XDR S. typhi harbouring blaCTX-M-15 in Karachi, Pakistan., Key Words: blaCTX-M-15, Salmonella typhi, Third generation cephalosporin, Typhoid fever, Extensively drug resistant.

The main aim of the present study was to evaluate the potential of orally disintegrating pellets (ODPs) as an approach for taste masking of bitter drugs, namely, Ambroxol hydrochloride (A-HCl) and Cetirizine dihydrochloride (C-DHCl). Pellets were prepared by extrusion/spheronization with Eudragit EPO, kyron T-134, Kyron T-314, mannitol, sorbitol, MCC (Avicel PH-101), sucralose, chocolate flavor, and 5% xanthum gum. The prepared pellets were characterized for percentage yield, drug content, particle size, in vitro drug release, and in vivo evaluation on humans for taste, mouth feel, and in vivo disintegration time. The results revealed that the average size of pellets was influenced greatly by the percentage of binder and extrusion speed. The optimized ODPs disintegrated in less than 20 s and showed more than 98% of drugs in ODPs dissolved within 15 min. Taste perception study was carried out on human volunteers to evaluate the taste masking ability of ODPs for taste, mouth feel, and in vivo disintegration time. Crystalline state evaluation of drugs in the optimized ODPs was conducted for X-ray powder diffraction. In conclusion, the study confirmed that ODPs can be utilized as an alternative approach for effective taste masking and rapid disintegration in the oral cavity.

Objective: To detect genes for enterotoxins, exfoliative and toxic shock syndrome toxins in Staphylococcus aureus (S. aureus) strains isolated from clinical specimens., Study Design: Cross-sectional observational study., Place and Duration of Study: Department of Molecular Genetics, Dr. Ziauddin Hospital, Karachi, from January to December 2010., Methodology: Two hundred and ninety eight S. aureus clinical isolates were obtained from various clinical samples received at Dr. Ziauddin Hospital, Karachi. Out of these, 115 were detected as methicillin resistant (MRSA) by cefoxitin disk diffusion test showing a prevalence rate of 38.6%. Detection of individual toxin genes was performed by Polymerase Chain Reaction (PCR) by using only one primer pair for each tube. Uniplex primers were preferred as multiplex primers are longer in base pairs and have the potential for cross reaction due to non-specific binding and increase in optimization time., Results: The possession of a single gene or more than a single gene in MRSA isolates was found in 61.73% of clinical samples; the highest number was found in pus swab, followed by sputum, blood, urethral swab, and urine. The prevalence of toxin genes was higher in MRSA as compared to methicillin sensitive (MSSA) isolates (19.12%)., Conclusion: PCR detects strains possessing toxin genes independent of their expression. The possession of genes for super-antigens seems to be a frequent and habitual trait of S. aureus more so in MRSA.

Objective: To test the hypothesis that Staphylococcus aureus genome has regulatory genes which coordinate the expression of extracellular products, and particular genes not expressed in vitro conditions may be turned on in a vivo environment., Methods: The study was conducted at the Immunology and Infectious Disease Research Laboratory (IIDRL), Microbiology Department, Husein Ebrahim Jamal Research Institute (HEJ), Animal House, Karachi University, from July to December 2009. Micro pore Teflon cages using a mouse cage model were fixed into the subcutaneous tissue in Albino mice (BALB/c) on their dorsal surface. After 15 days, the holes closed down with healthy tissue. Three staphylococcal isolates from clinical samples confirmed by DNA sequencing of 16s ribosomal RNA were tested for expression of extracellular protein in vitro and were later injected into the cages. After the institution of infection, the fluid aspirated from the cages was analysed by Sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE). This was done to test for possible induction of additional extracellular proteins in vivo., Results: The appearance of enhanced extracellular products was observed in the fluid recovered from the cages of two mice on days 5 and 7 subsequent to the institution of infection, suggesting a turn-on of particular genes which were not expressed in vitro conditions., Conclusions: In-vivo host and environmental signals contribute to the induction of genes for the production of extracellular proteins.

Introduction: The purpose of this study was to observe the formation of biofilm, an important virulence factor, by isolates of Staphylococcus aureus (S. aureus) in Pakistan by different conventional methods and through electron microscopy., Methodology: We screened 115 strains of S. aureus isolated from different clinical specimens by tube method (TM), air-liquid interface coverslip assay method, Congo red agar (CRA) method, and scanning electron microscopy (SEM)., Results: Out of 115 S. aureus isolates, 63 (54.78%) showed biofilm formation by tube method. Biofilm forming bacteria were further categorized as high producers (n = 23, 20%) and moderate producers (n = 40, 34.78%). TM coordinated well with the coverslip assay for strong biofilm-producing strains in 19 (16.5%) isolates. By coverslip method, weak producers were difficult to differentiate from biofilm negative isolates. Screening on CRA showed biofilm formation only in four (3.47%) strains. Scanning electron micrographs showed the biofilm-forming strains of S. aureus arranged in a matrix on the propylene surface and correlated well with the TM., Conclusion: Biofilm production is a marker of virulence for clinically relevant staphylococcal infections. It can be studied by various methods but screening on CRA is not recommended for investigation of biofilm formation in Staphylococcus aureus. Electron micrograph images correlate well with the biofilm production as observed by TM.

Warm antibody autoimmune haemolytic anaemia, a rare disease (0.2-1 per 100,000 populations), is due to the presence of warm agglutinins that react with protein antigens on the surface of red blood cells causing their premature destruction. Here, we present a case report of a 10 year old girl who came with features of haemolytic anaemia and history of blood transfusion since 3 years. On admission. laboratory test revealed that she had autoimmune hepatitis type 1 and was also an asymptomatic carrier of hepatitis B virus with positive HBs Ag. Steroid therapy resulted in clinical and laboratory remission. Direct antiglobulin test was negative after anaemia resolution, hepatitis B virus antigenemia persisted. To our knowledge, warm antibody autoimmune hemolytic anaemia has not previously been described in association with autoimmune hepatitis and asymptomatic carrier state of hepatitis B virus.

Objective: To determine the pattern of antibiotic resistance in the clinical isolates of Staphylococcus (S.) aureus, Methicillin Resistant S. aureus (MRSA) and define the possible emergence of Vancomycin resistant S. aureus (VRSA) in Karachi., Study Design: An observational study., Place and Duration of Study: Essa Laboratories and Department of Molecular Genetics, Ziauddin Hospital, from January to December 2009., Methodology: Staphylococcal isolates from different clinical specimens, pus, urine, blood, high vaginal swab and other secretions received at Ziauddun laboratories and Dr.Essa laboratories were collected. The specimens were inoculated on blood agar, MacConkey agar and Chrom agar. Antibiotic susceptibility to conventional antibiotics was done by disc diffusion, and E-test. Methicillin resistance was tested by using Oxacillin and Methicillin disks and confirmed by gold standard PCR for presence of mecA gene. All MRSA strains were subjected in addition to Vancomycin screen agar test., Results: Out of the 450 S. aureus isolates 174 (38.6%) were found to be MRSA. In those isolates, high resistance was found to Cefixime (100%) Doxicycline (100%) Oxacillin (96.5%) Gentamicin, (96.3%), Timethoprim/Sulfametoxazole (95.6%) Chloramphenicol (93%) Tobramicin (81.03%), Ofloxacin (72.4%) and Ciprofloxacin (63.7%). Low resistance was found to Ceftazidine (36%), Amoxicillin/Clavulanate (32.7%), Fosfomycin (31%), Cefroxime (24%), Amikacin (17.2%) and Meropenem (13%). One isolate was found to be Vancomycin resistant (MIC 32 μg/ml). Four isolates had intermediate resistance, with two strains having MIC of 16μg/ml and two having MIC of 8μg/ml. These strains were also resistant to all the other tested antibiotics except Linezolid to which all isolates were susceptible., Conclusion: Antibiotic resistance to all the conventionally used antibiotics was high in the tested isolates. All the strains were susceptible to Linezolid which is an expensive alternative with adverse side effects. Judicious use of antibiotics focused on the compliance and formation of antibiotic policy guide lines is highly recommended.

Objective: This study was conducted to detect the sensitivity and specificity of various diagnostic tests on biopsy specimens obtained from patients undergoing elective endoscopy, by culture, histopathology (special stain), urease (biochemical test) and the presence of specific antibodies by serology for the detection of Helicobacter pylori., Place and Duration of Study: This study was conducted in Civil Hospital, Karachi, in collaboration with Dr. Essa Laboratories and IIDRL (Immunology and Infectious Disease Research Laboratory), Karachi University, from June 99-to July 2000., Subjects and Methods: Biopsy material was taken from 50 patients referred for elective endoscopy with symptoms of various upper gastrointestinal diseases. Non-endoscopic methods serology and endoscopic biopsy specimens using urease test, by culture and histopathology using special stain, detected presence of H. pylori. Sensitivity and specificity was calculated using the standard formula, only those cases were taken as true positive which were positive by either culture test and/or special stain. Those cases giving positive results only by serology or urease test not supported by either of the direct tests were taken as false positive, Results: The percentage of positive cases detected was 81% by serology, 80% by histopathology, 9% by culture and 56% by urease test. Sensitivity and specificity was by serology 84% and 60%, histopathology (special stain) 83% and 100%, culture 64% and 100% and by urease test 67% and 85% respectively., Conclusion: H. pylori infection can be detected by a variety of methods. The simplest and least expensive method is serology. Positive serology does not distinguish between active and chronic infection and is less specific as compared to other methods. Histopathology (special stain) allows simultaneous evaluation of tissue injury and has a high degree of sensitivity and specificity. Culture can be used to detect antibiotic resistant organisms.