Use of pefloxacin as a surrogate marker to detect ciprofloxacin susceptibility in Salmonella enterica serotypes typhi and paratyphi A

Objective: To determine the use of pefloxacin as a surrogate marker to detect fluoroquinolone (ciprofloxacin) susceptibility against Salmonella enterica serotypes Typhi and Paratyphi A.Methods: The prospective, descriptive cross-sectional study was conducted at the Aga Khan University Hospital, Karachi, from September 2016 to March 2018, and comprised Salmonella Typhi and Paratyphi A isolates of blood cultures. Disk susceptibility tests and broth microdilution to test minimum inhibitory concentration were performed as per standard guidelines. Data was analysed using SPSS 21.Results: Of the 138 isolates, 91(66%) were intermediate resistant to ciprofloxacin but were resistant to pefloxacin, 42(30%) were resistant to both ciprofloxacin and pefloxacin, and 5(4%) were susceptible to both ciprofloxacin and pefloxacin. Of the isolates that were intermediate resistant to ciprofloxacin, 85(93%) had minimum inhibitory concentration range0.12-0.5mg\L, while 6(7%) had MIC\u3e1mg\L (p\u3c0.0001).Conclusions: Pefloxacin disk diffusion test was found to be reliable in detecting fluoroquinolone resistance among enteric fever causing Salmonella

Screening for triazole resistance in clinically significant aspergillus species; report from Pakistan

Background: Burden of aspergillosis is reported to be significant from developing countries including those in South Asia. The estimated burden in Pakistan is also high on the background of tuberculosis and chronic lung diseases. There is concern for management of aspergillosis with the emergence of azole resistant Aspergillus species in neighbouring countries in Central and South Asia. Hence the aim of this study was to screen significant Aspergillus species isolates at the Microbiology Section of Aga Khan Clinical Laboratories, Pakistan, for triazole resistance.Methods: A descriptive cross-sectional study, conducted at the Aga Khan University Laboratories, Karachi, from September 2016-May 2019. One hundred and fourteen, clinically significant Aspergillus isolates [A. fumigatus (38; 33.3%), A. flavus (64; 56.1%), A. niger (9; 7.9%) A. terreus (3; 2.6%)] were included. The clinical spectrum ranged from invasive aspergillosis (IA) (n = 25; 21.9%), chronic pulmonary aspergillosis (CPA) (n = 58; 50.9%), allergic bronchopulmonary aspergillosis (ABPA) (n = 4; 3.5%), severe asthma with fungal sensitization (SAFS) (n = 4; 3.5%), saprophytic tracheobronchial aspergillosis (n = 23; 20.2%). Screening for triazole resistance was performed by antifungal agar screening method. The minimum inhibitory concentration (MIC) of 41 representative isolates were tested and interpreted according to the Clinical and Laboratory Standards Institute broth microdilution method.Results: All the isolates were triazole-susceptible on agar screening. MICs of three azole antifungals for 41 tested isolates were found to be ≤1 ml/L; all isolates tested were categorized as triazole-susceptible, including 4 isolates from patients previously on triazole therapy for more than 2 weeks. The minimum inhibitory concentration required to inhibit the growth of 90% organisms (MIC90) of itraconazole, voriconazole and posaconazole of the representative Aspergillus isolates was 1 mg/L, 1 mg/L and 0.5 mg/L, respectively.Conclusion: Triazole resistance could not be detected amongst clinical Aspergillus isolates from the South of Pakistan. However, environmental strains remain to be tested for a holistic assessment of the situation. This study will set precedence for future periodic antifungal resistance surveillance in our region on Aspergillus isolates

Staphylococcus aureus Bacteraemia in Patients with Chronic Kidney Disease: Single-Centre Data from Pakistan

Background: Infection, especially Staphylococcus aureus bacteraemia (SAB), increases morbidity and mortality in patients with chronic kidney disease (CKD), particularly those who are dialysis-dependent. This study describes the clinical features of SAB amongst patients with CKD. Method: The authors planned a retrospective observational study of adult patients with CKD and SAB from January 2021–June 2022. Microbiology laboratory data and hospital medical records were reviewed. All detailed clinical data, including baseline characteristics, source of infection, management, methicillin susceptibility of S. aureus isolates, and outcome, were collected. The association between baseline characteristics, source of infection, management, and outcome of patients, was examined. Results: The authors included 49 patients in their study. Methicillin-resistant  S. aureus was more prevalent (35 out of 49; 71.4%) than methicillin-sensitive  S. aureus (14 out of 49; 28.6%). Central venous catheter was the most common source of infection (38 out of 49; 77.6%). Most patients recovered (26 out of 49; 53.1%), while 12 (24.5%) were referred to other hospitals. Four patients expired. Methicillin-resistant S. aureus bacteraemia had higher mortality than methicillin-sensitive S. aureus bacteraemia. Central line-associated bloodstream infections showed higher mortality than other sources of infection, although due to a small sample size, this difference could not be proven statistically. SAB showed significant association with patient outcomes. The central venous catheter could not be removed in three of four expired patients (p=0.018). Conclusion: SAB is a serious but preventable nosocomial infection in patients with CKD who are dependent on dialysis. Strict infection prevention measures are needed to prevent hospital-acquired infections in these patients

C. auris and non-C. auris candidemia in hospitalized adult and pediatric COVID-19 patients; single center data from Pakistan

We compared candidemia due to Candida auris and other non-C.auris cases in hospitalized COVID-19 patients over a period of nine months at our institution. Candidemia cases in all admitted patients (with or without COVID-19) from April-December 2020 were identified. Electronic records were accessed to record clinical data of COVID-19 patients with candidemia. For statistical analysis, independent samples Mann-Whitney U test was used for continuous and Fisher\u27s exact test was used for categorical variables.A total of 26 candidemia cases (four C.auris, 22 non-C.auris) in 2438 admitted COVID-19 (10.7 per 1000 admissions) and 59 candidemia cases (six C.auris, 53 non-C.auris) in admitted non-COVID patients (8.2 per 1000 admission) were identified. The proportion of C.auris candidemia in COVID-19 and non-COVID-19 patients was 15.4% and 10% respectively. 4/26 of COVID-19 candidemia patients were aged ≤ 15 years (10 months-15 years). Comparison of C.auris and non-C.auris candidemia cases reveal significant difference in prior antifungal exposure, present in 100% C.auris candidemia versus 27% non-C.auris candidemia patients (p-value 0.014). Although not statistically significant, C.auris candidemia patients had a longer stay in hospital before candidemia (20 vs 9 days), higher isolation rate of multidrug resistant bacteria (100% vs 50%), increased rate of prior colonization of Candida species (50% vs 14%) and lower mean beta-d-glucan levels (48.73 pg/mL vs. 138.146 pg/mL). Both C.auris and non-C.auris COVID-19 patients had similar mortality rate (67% vs 65%). A significant number of critically ill COVID-19 patients developed candidemia in our study highlighting the need for prompt diagnosis and management.Lay summary: 26 candidemia cases (4 Candida auris;22 non-C.auris) in COVID-19 patients (April-December 2020) are reported from Pakistan. Compared to non-C.auris, C.auris candidemia patients had higher prior antifungal exposure, longer hospital stay, higher MDR bacteria and increased rate of Candida colonization

Autoimmune response to AGE modified human DNA: Implications in type 1 diabetes mellitus

Aims: Non-enzymatic glycation of DNA both in vivo and in vitro results in generation of free radicals, known as glycoxidation. Glycoxidation leads to structural perturbation of DNA resulting in generation of neo-antigenic epitopes having implication in autoimmune disorders like diabetes mellitus. In this study human placental DNA was glycated with methylglyoxal (MG) and lysine (Lys) in the presence of Cu2+ and its auto-antibody binding was probed in Type 1 diabetes patients. Methods: Glycation was carried out by incubating DNA with MG, Lys and Cu2+ for 24 h at 37 °C. Carboxyethyl deoxyguanosine (CEdG) formed in glycation reaction was studied by LC-MS and the pathway for Amadori formation was studied by ESI-MS techniques. Furthermore, binding characteristics of auto-antibodies in diabetes patients were assessed by direct binding, competitive ELISA and band shift assay. Results: DNA glycation with MG, Lys and Cu2+ results in the formation of CEdG (marker of DNA glycation) which was confirmed by LC-MS. The intermediate stages of glycation were confirmed by ESI-MS technique. Serum from diabetes patients exhibited enhanced binding and specificity for glycated DNA as compared to native form. Conclusions: Glycation of DNA has resulted in structural perturbation causing generation of neo-antigenic epitopes thus recognizing auto-antibodies in diabetes

N-OH-AABP Modifications in Human DNA May Lead to Auto-Antibodies in Bladder Cancer Subjects

4-Aminobiphenyl (4-ABP) and other related arylamines have emerged to be responsible for human urinary bladder tumors and cancers. Hemoglobin-ABP adducts have been recognized in the blood of smokers, and it builds up in the circulatory system over the period of years that might lead to a bladder tumor. N-hydroxy-Acetyl 4-Aminobiphenyl (N-OH-AABP) is one of the reactive forms of 4-ABP which has a potential to initiate tumor growth and causes cancer rapidly. In the present study, commercially available human DNA was modified by N-OH-AABP, and its modifications were analyzed biophysically from fluorescence spectroscopy and thermal denaturation studies. Further, Sera and IgG from bladder cancer patients’ blood were assessed for affinity to native and N-OH-AABP modified human DNA using ELISA. The study showed N-OH-AABP caused damage in the structure of the DNA macromolecule and the perturbations resulting from damage leads to change in the Tm of the DNA molecule. Bladder cancer auto-antibodies, particularly in smoker group, showed preferential binding to N-OH-AABP modified human DNA. This study shows that N-OH-AABP modified DNA could be an antigenic stimulus for the generation of autoantibodies in the sera of bladder cancer patients

Characteristics and outcomes of COVID-19 patients admitted to hospital with and without respiratory symptoms

Background: COVID-19 is primarily known as a respiratory illness; however, many patients present to hospital without respiratory symptoms. The association between non-respiratory presentations of COVID-19 and outcomes remains unclear. We investigated risk factors and clinical outcomes in patients with no respiratory symptoms (NRS) and respiratory symptoms (RS) at hospital admission. Methods: This study describes clinical features, physiological parameters, and outcomes of hospitalised COVID-19 patients, stratified by the presence or absence of respiratory symptoms at hospital admission. RS patients had one or more of: cough, shortness of breath, sore throat, runny nose or wheezing; while NRS patients did not. Results: Of 178,640 patients in the study, 86.4 % presented with RS, while 13.6 % had NRS. NRS patients were older (median age: NRS: 74 vs RS: 65) and less likely to be admitted to the ICU (NRS: 36.7 % vs RS: 37.5 %). NRS patients had a higher crude in-hospital case-fatality ratio (NRS 41.1 % vs. RS 32.0 %), but a lower risk of death after adjusting for confounders (HR 0.88 [0.83-0.93]). Conclusion: Approximately one in seven COVID-19 patients presented at hospital admission without respiratory symptoms. These patients were older, had lower ICU admission rates, and had a lower risk of in-hospital mortality after adjusting for confounders