Search

Kokab Jabeen,1 Sidrah Saleem,1 Shah Jahan,1 Summiya Nizamudin,2 Faiqa Arshad,1 Zill-e Huma,1 Syed Mohsin Raza,3 Maria Mehmood,1 Muhammad Roman,1 Faiz Ul Haq1 1Department of Microbiology, University of Health Sciences, Lahore, Pakistan; 2Department of Microbiology, Shaukat Khanum Memorial Cancer Hospital & Research Centre, Lahore, Pakistan; 3Department of Allied Health Sciences, University of Health Sciences, Lahore, PakistanCorrespondence: Kokab Jabeen, Tel +92 3128878893, Email kaukab_jabeen@yahoo.comBackground: The emergence of extensively drug-resistant (XDR) typhoid in Pakistan has endangered the treatment options available to manage this infection. Third generation cephalosporin were the empiric choice to treat typhoid fever in Pakistan, but acquisition of ESBLs have knocked them out of the arsenal. The current empiric choice is azithromycin which is vulnerable to resistance too. This study aimed to assess the burden of XDR typhoid and the frequency of resistance determinants in blood culture samples collected from different hospitals in Lahore, Pakistan.Methods: A total of 835 blood cultures were collected from different tertiary care hospitals in Lahore during January 2019 to December 2021. Among 835 blood cultures, 389 Salmonella Typhi were identified, and 150 were XDR S. Typhi (resistant to all recommended antibiotics). Antibiotics resistance genes of the first-line drugs (blaTEM-1, catA1, sul 1, and dhfR7) and second line drugs (gyrB, gyrA, qnrS, ParC and ParE) were investigated among XDR S. Typhi. There were different CTX-M genes isolated using the specific primers, blaCTX-M-U, blaCTX-M-1, blaCTX-M-15, blaCTX-M-2, blaCTX-M-8 and blaCTX-M-9.Results: Antibiotic resistant genes of the first-line drugs were isolated with different frequency, blaTEM-1 (72.6%), catA1 (86.6%), sul 1 (70%), and dhfR7 (56%). Antibiotics resistance genes of second-line drugs were isolated as: gyrB (60%), gyrA (49.3%), qnrS (32.6%), parC (44%) and parE (28%). Among CTX-M genes, blaCTX-M-U (63.3%) was the most frequent followed by blaCTX-M-15 (39.3%) and blaCTX-M-1 (26%).Conclusion: Our study concluded that XDR isolates circulating in Pakistan have acquired first-line and second-line antibiotic resistant genes quite successfully along with CTX-M genes (ESBLs) rendering them resistant to the third generation cephalosporins as well. Emergence of azithromycin resistance in XDR S. Typhi which is currently used as an empiric treatment option is worrisome and needs to be monitored carefully in endemic countries like Pakistan.Keywords: Salmonella, antimicrobial resistance, plasmids, XDR typhoid

Faiqa Arshad,1 Sidrah Saleem,1 Romeeza Tahir,2 Shah Jahan,2 Kokab Jabeen,3 Aneela Khawaja,4 Zille Huma,1 Muhammad Roman,1 Faheem Shahzad2 1Department of Microbiology, University of Health Sciences, Lahore, Punjab, Pakistan; 2Department of Immunology, University of Health Sciences, Lahore, Punjab, Pakistan; 3Department of Pathology, Ammer ud Din Medical College, PGMI, Lahore, Punjab, Pakistan; 4Department of Pathology, Rahbar Medical & Dental College, Lahore, Punjab, PakistanCorrespondence: Faiqa Arshad, Department of Microbiology, University of Health Sciences, Khayaban-e-Jamia, Block D Muslim Town, Lahore, Punjab, 54600, Pakistan, Email drfaiqaimran@gmail.comBackground: The association of treatment failure and mortality with vancomycin minimum inhibitory concentration creep (MIC) is a matter of serious concern in patients with severe methicillin resistant Staphylococcus aureus (MRSA) infections. The purpose of the study was to identify and characterize staphylococcal cassette chromosome mec (SCCmec) and clonal types of MRSA strains, exhibiting the vancomycin MIC creep phenomenon.Methods: A total of 3305 S. aureus strains were isolated from various clinical samples of Lahore General Hospital, Lahore, Pakistan. MRSA strains were identified by cefoxitin resistant (≤ 21mm) followed by mecA and mecC gene genotyping. Vancomycin MIC creep was determined by E-test. Isolates having MIC values > 1.5 μg/mL were further subjected for SCCmec typing (I–V and XI) and multiple-locus variable number tandem repeat analysis (MLVA) by amplification of spa, sspA, clfA, clfB, and sdrCDE genes. A dendrogram was created based on the similarity index using bioneumerics software.Results: About 13.3% (440/3305) isolates were MRSA with 99.3% (437/440) and 0.7% (3/440) carried mecA and mecC genes, respectively. In 120 MRSA isolates, the MIC of vancomycin was > 1.5μg/mL. In MRSA isolates with high vancomycin MIC (> 1.5μg/mL), the most common SCCmec type was SCCmec III (38.3%), followed by SCCmec IVa (15.8%), SCCmec IIIa (13.3%,), SCCmec IVc (7.5%), SCCmec IVe (5.8%), SCCmec IVd (5.8%), SCCmec IVb (4.2%), SCCmec II (2.5%), SCCmec V (1.7%), SCCmec I (1.7%) and SCCmec XI (1.7%). MLVA revealed 60 genotypic groups of MRSA isolates having a 92% similarity index.Conclusion: SCCmec III was the most common type in genetically related MRSA isolates showing vancomycin MIC creep. The presence of SCCmec XI may further add burden to infection control measures.Keywords: methicillin resistant Staphylococcus aureus, staphylococcal chromosomal cassette, multilocus variable number tandem repeat analysis

Salima Qamar, Najma Shaheen, Sadia Shakoor, Joveria Farooqi, Kauser Jabeen, Rumina Hasan Clinical Microbiology, Department of Pathology And Laboratory Medicine, Aga Khan University Hospital, Karachi, Pakistan Introduction: Management of infections with carbapenem-resistant Enterobacteriaceae (CRE) is challenging. In recent times, agents such as colistin and fosfomycin have been used in combination with other antibiotics to treat such infections. In this study, we aim to seek frequency of colistin and fosfomycin resistance in CRE from Pakistan.Methods: This study was conducted at clinical laboratories, Aga Khan University Hospital. In total, 251 CRE were included in the study. Colistin minimum inhibitory concentrations (MICs) were performed using broth microdilution (BMD) method and VITEK® 2 system, whereas fosfomycin susceptibility was performed using Kirby–Bauer method. MIC50 and MIC90 were calculated for colistin and agreement between VITEK and BMD was also calculated.Results: Out of 251 strains colistin MIC of ≥4 µg/mL was seen in 40 (15.9%). Of these strains 20 (50%) were Klebsiella pneumoniae. Colistin MIC50 and MIC90 were found to be 0.5 and 16 µg/mL, respectively. BMD and VITEK 2 showed 100% categorical agreement. Essential agreement was 88.5% with kappa score 0.733 indicating strong agreement between VITEK and BMD. 31 out of 251 (12.3%) CREs were resistant to fosfomycin.Conclusion: Study shows frequency of colistin and fosfomycin resistance to be 15.9% and 12.3%, respectively. In countries where rate of CREs is high, emerging resistance against these last resort antibiotics is alarming as it leaves clinicians with almost no options to manage such multidrug resistant and extensively drug resistant infections. Keywords: emerging drug resistance, colistin resistance, fosfomycin resistance, carbapenam resistant enterobacteriaceae, salvage antibiotics

Ochratoxigenic fungal species are a major cause of various infections in plants and posed serious threat to their consumers, including humans and animals. The objective of this study was to examine the in vitro efficacy of different concentrations of leaves methanolic extract of Amaranthus viridis L. against target pathogenic ochratoxin producing fungal species (Trichoderma viride Pers., Trichoderma harzianum Rifai. and Cladosporium cladosporioides (Fresen.) G.A. de Vries). For this purpose, different concentrations viz. 2%, 4%, 6%, 8% and 10% of leaf methanolic extract was prepared and tested for their antifungal potential in a completely randomized design (CRD). Results revealed that a 10%concentration of A. viridis significantly suppressed the growth of all the tested fungi. The phytochemical analysis of A. viridis depicts the presence of glycosides, alkaloids, saponins, tannins and coumarins. Bioassay-guided fractionation was executed to check the antifungal activity of various fractions in vitro against the test ochratoxin producing fungi. The ethyl acetate fraction showed the highest antifungal activity among all other fractions. GC-MS (Gas chromatography- mass spectroscopy) analysis of ethyl acetate fraction revealed the presence of twelve compounds viz. 1,2,3-propanetriol monoacetate; 푛-decanoic acid; 1-hexadecene; dodecanoic acid; 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-[R]; tetradecanoic acid, 2-pentadecanone; 6,10,14-trimethyl-; phenol,2-methyl-5-[1-methylethyl]-; 푛-hxadecanoic acid; 2[4H]-benzofuranone; phytol; 9,12-octadecadienoic acid and heptacosane. The presence of these compounds might be responsible for the antifungal potential of A. viridis and it can be concluded that the methanolic leaf extract of the tested plant proved to be beneficial for inhibiting the growth of test ochratoxigenic fungi. [ABSTRACT FROM AUTHOR]

This work deals with the effects of suction and injection on Casson nanofluid around a moving wedge under the influence of gyrotactic micro-organisms along with viscous and ohmic dissipation. The governing system of highly coupled nonlinear partial differential equations together with assisting boundary conditions is converted by applying suitable similarity transformations, into a set of nonlinear ordinary differential equations. The obtained flow model is solved numerically by bvp4c (matlab) procedure. The accuracy of the flow model under consideration is validated by employing another well-known mathematical technique Runge-Kutta-Fehlberg (RKF) having good agreement while comparing the numerical results obtained by bvp4c for both suction and injection cases. Impacts of various pertinent parameters active in the flow model such as thermophoresis and Brownian motion, moving wedge, magnetic field, viscous and ohmic dissipation are numerically calculated for both suction and injection flow situations and also presented graphically. It is observed that the increase in casson parameter enhances the velocity but declines the density of motile organism, concentration and temperature for suction as well as injection flow case. The impacts of mass transfer rate of gyrotactic micro-organisms, Nusselt and Sherwood numbers for various fluid parameters are numerically presented in tabular form, separately for both suction and injection. One of the important observations of this study is that the suction or injection plays a key role in controlling boundary layer flow and brings stability in the flow. Moreover, rate of heat and mass transfer get enhanced in the existence of gyrotactic micro-organisms. Further, it would be worth mentioning that physical behavior of this flow problem coincides very well with already published literature either graphically or in tabular representation. [ABSTRACT FROM AUTHOR]