Prevalence and molecular characterization of methicillin resistance among Coagulase-negative Staphylococci at a tertiary care center.

BACKGROUND: Methicillin-resistant Coagulase-negative Staphylococci (MR-CoNS) have emerged as an important cause of nosocomial infections especially in patients with prosthetic devices and implants. This study was conducted with an aim to determine the prevalence of methicillin resistance among CoNS isolates at a tertiary care center by both phenotypic and genotypic methods. METHODS: This cross sectional study was carried out from September 2011 to February 2014 in which 150 non-repetitive clinical isolates of CoNS were identified at the species level by conventional phenotypic methods. Cefoxitin disk (30 µg) diffusion testing was used to determine methicillin resistance and confirmed by detection of mecA gene by polymerase chain reaction (PCR). RESULTS: Out of 150 CoNS isolates, 51 were methicillin resistant by cefoxitin disk diffusion method. Out of these 51 isolates, mecA gene was detected only in 45 isolates. Moreover, mecA gene was also detected in 4 isolates, which were cefoxitin sensitive. Thus, the prevalence of methicillin resistance among CoNS was found to be 32.7% by PCR. CONCLUSION: The prevalence of methicillin resistance among Coagulase-negative Staphylococci (CoNS) was 32.7% by PCR detection of mecA gene. The sensitivity and specificity of cefoxitin disk diffusion method against mecA gene detection by PCR were found to be more than 90%. It can be concluded from this study that cefoxitin disk diffusion test can be used as a useful screening method to detect methicillin resistance among CoNS isolates. However, detection of mecA gene by PCR remains a more accurate method of detecting methicillin resistance among CoNS.

Species distribution and antimicrobial resistance pattern of Coagulase-negative Staphylococci at a tertiary care centre.

BACKGROUND: Coagulase-negative Staphylococci (CoNS), previously dismissed at contaminants, have now emerged as an important cause of nosocomial infections especially in patients with implants and prosthetic devices. They are a well-known cause of bloodstream infections, urinary tract infections, wound infections, prosthetic valve endocarditis and eye infections. This study was conducted with an aim to identify CoNS at the species level from various clinical samples and determine the antimicrobial resistance pattern of these isolates. METHODS: This cross sectional study was carried out from September 2011 to February 2014 in which 150 non-repetitive clinical isolates of CoNS were identified at the species level by conventional phenotypic methods. Complete antimicrobial susceptibility profile was also determined by Kirby Bauer disc diffusion method. Susceptibility testing to vancomycin was done by E-test method. RESULTS: Only three species of CoNS were isolated, the most common being Staphylococcusepidermidis (60%) followed by Staphylococcussaprophyticus (27.3%) and Staphylococcushemolyticus (12.7%). Most S. epidermidis were isolated from blood and intravascular catheter tip samples, whereas all S. saprophyticus were isolated from urine samples of female patients. All isolates were found to be resistant to penicillin, but were susceptible to glycopeptides and linezolid and showed variable resistance to fluoroquinolones, aminoglycosides and macrolides. CONCLUSION: CoNS are emerging nosocomial pathogens and should not always be overlooked as contaminants. However, growth of CoNS from blood cultures and intravascular catheter tips should be clinically correlated and carefully interpreted. As many CoNS strains exhibit drug resistance, antimicrobial susceptibility profile should be determined prior to treatment of these infections.

Causes and predictors of unplanned reoperations within 30 days post laparoscopic pancreaticoduodenectomy: a comprehensive analysis.

Objective: To delineate the risk factors and causes of unplanned reoperations within 30 days following laparoscopic pancreaticoduodenectomy (LPD). Methods: A retrospective study reviewed 311 LPD patients at Ningbo Medical Center Li Huili Hospital from 2017 to 2024. Demographic and clinical parameters were analyzed using univariate and multivariate analyses, with P < 0.05 indicating statistical significance. Results: Out of 311 patients, 23 (7.4%) required unplanned reoperations within 30 days post-LPD, primarily due to postoperative bleeding (82.6%). Other causes included anastomotic leakage, abdominal infection, and afferent loop obstruction. The reoperation intervals varied, with the majority occurring within 0 to 14 days post-surgery. Univariate analysis identified significant risk factors: diabetes, liver cirrhosis, elevated CRP on POD-3 and POD-7, pre-operative serum prealbumin < 0.15 g/L, prolonged operation time, intraoperative bleeding > 120 ml, vascular reconstruction, soft pancreatic texture, and a main pancreatic duct diameter ≤3 mm (all P < 0.05). Multivariate analysis confirmed independent risk factors: pre-operative serum prealbumin < 0.15 g/L (OR = 3.519, 95% CI 1.167-10.613), CRP on POD-7 (OR = 1.013, 95% CI 1.001-1.026), vascular reconstruction (OR = 9.897, 95% CI 2.405-40.733), soft pancreatic texture (OR = 5.243, 95% CI 1.628-16.885), and a main pancreatic duct diameter ≤3 mm (OR = 3.462, 95% CI 1.049-11.423), all associated with unplanned reoperation within 30 days post-LPD (all P < 0.05). Conclusion: Postoperative bleeding is the primary cause of unplanned reoperations after LPD. Independent risk factors, confirmed by multivariate analysis, include low pre-operative serum prealbumin, elevated CRP on POD-7, vascular reconstruction, soft pancreatic texture, and a main pancreatic duct diameter of ≤3 mm. Comprehensive peri-operative management focusing on these risk factors can reduce the likelihood of unplanned reoperations and improve patient outcomes.

Antiviral prophylaxis or preemptive therapy for cytomegalovirus after liver transplantation?: A systematic review and meta-analysis.

Background: To conduct a meta-analysis with the aim of comparing the outcomes of antiviral prophylaxis and preemptive therapy for the prevention of cytomegalovirus (CMV) infection in liver transplant (LT) recipients. Methods: We searched databases for qualified studies up until March 2022. Finally, a meta-analysis was carried out using a fixed-effect or random-effect model based on the heterogeneity. Results: With a total of 1834 LT patients, the pooled incidence of CMV infection and CMV disease in the overall LT recipients using antiviral prophylaxis and preemptive therapy were 24.7% vs. 40.4% and 6.4% vs. 9.4%, respectively. Our meta-analysis exhibited a significant reduction in the incidence of CMV infection due to antiviral prophylaxis when compared to preemptive therapy in the high-risk group (OR: 6.67, 95% CI: 1.73, 25.66; p = 0.006). In contrast, there was a significant reduction in the incidence of late-onset of CMV disease in preemptive therapy compared to antiviral prophylaxis in the high-risk group (OR: 0.29, 95% CI: 0.12, 0.74; p = 0.009). However, the incidence of CMV disease, allograft rejection, graft loss, drug related adverse effects, opportunistic infections and mortality did not differ significantly between both the interventions (all p> 0.05). Conclusions: We found the use of antiviral prophylaxis, compared with preemptive therapy, is superior in controlling CMV infection and prolonging the time to CMV disease in LT recipients without an increased risk of opportunistic infections, allograft rejection, graft loss, drug related adverse effects, development of drug resistance, and mortality.

Diagnostic performance of GeneXpert MTB/RIF assay compared to conventional Mycobacterium tuberculosis culture for diagnosis of pulmonary and extrapulmonary tuberculosis, Nepal.

Tuberculosis is an infectious disease caused by the Mycobacterium tuberculosis. It is a global health problem and major cause of death in resource-limited countries like Nepal. Timely diagnosis with sensitive testing methods could assist in early management of the disease. This study was conducted to compare the diagnostic performance of GeneXpert MTB/RIF and conventional acid-fast staining with M. tuberculosis culture. The study was carried out in the Department of Microbiology, Shree Birendra Army Hospital, Nepal. Samples (n=500) were tested with a GeneXpert MTB/RIF assay and acid-fast bacilli (AFB) smear microscopy. All samples were sent for M. tuberculosis conventional culture by the German-Nepal Tuberculosis Project, Kathmandu, Nepal (GENETUP). Out of a total 500 pulmonary and extrapulmonary samples tested, 97 samples were positive for M. tuberculosis by GeneXpert MTB/RIF assay. Out of the positive samples, only 95 samples were found positive by the culture method. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of AFB microscopy was 45.3%, 99.5%, 99.5% and 88.5%, respectively. The sensitivity, specificity, PPV and NPV of GeneXpert MTB/RIF was found to be 100%, 99.5%, 97.5% and 100%, respectively compared to the gold standard culture method. The GeneXpert MTB/RIF test was comparable with culture diagnosis of both pulmonary and extrapulmonary tuberculosis cases.

Liquid biopsy in pancreatic cancer: the beginning of a new era.

With dismal survival rate pancreatic cancer remains one of the most aggressive and devastating malignancy. Predominantly, due to the absence of a dependable methodology for early identification and limited therapeutic options for advanced disease. However, it takes over 17 years to develop pancreatic cancer from initiation of mutation to metastatic cancer; therefore, if diagnosed early; it may increase overall survival dramatically, thus, providing a window of opportunity for early detection. Recently, genomic expression analysis defined 4 subtypes of pancreatic cancer based on mutated genes. Hence, we need simple and standard, minimally invasive test that can monitor those altered genes or their associated pathways in time for the success of precision medicine, and liquid biopsy seems to be one answer to all these questions. Again, liquid biopsy has an ability to pair with genomic tests. Additionally, liquid biopsy based development of circulating tumor cells derived xenografts, 3D organoids system, real-time monitoring of genetic mutations by circulating tumor DNA and exosome as the targeted drug delivery vehicle holds lots of potential for the treatment and cure of pancreatic cancer. At present, diagnosis of pancreatic cancer is frantically done on the premise of CA19-9 and radiological features only, which doesn't give a picture of genetic mutations and epigenetic alteration involved. In this manner, the current diagnostic paradigm for pancreatic cancer diagnosis experiences low diagnostic accuracy. This review article discusses the current state of liquid biopsy in pancreatic cancer as diagnostic and therapeutic tools and future perspectives of research in the light of circulating tumor cells, circulating tumor DNA and exosomes.

Salvage Liver Transplant versus Primary Liver Transplant for Patients with Hepatocellular Carcinoma.

The strategy of salvage liver transplantation (SLT) originated for initially resectable and transplantable hepatocellular carcinoma (HCC) to preclude upfront transplantation, with SLT in the case of recurrence. However, SLT remains a controversial approach in comparison to primary liver transplant (PLT). The aim of our study was to conduct a systemic review and meta-analysis to assess the short-term outcomes, overall survival (OS), and disease-free survival (DFS) between SLT and PLT for patients with HCC, stratifying results according to the Milan criteria and donor types. A search of PubMed, EMBASE, and the Cochrane Library was conducted to identify studies comparing SLT and PLT. A fixed effects model and a random effects model meta-analysis were conducted to assess the short-term outcomes, OS, and DFS based on the evaluation of heterogeneity. SLT had superior 1-year, 3-year, and 5-year OS and DFS compared with that of PLT. After classifying data according to donor type and Milan criteria, our meta-analysis revealed: that for deceased-donor liver transplantation (DDLT) recipients, there were no significant differences in 1-year and 3-year OS rate between the SLT group and the PLT group. However, the 5-year OS rate was superior in the SLT group compared to the PLT group. Similarly, SLT had superior 1-year, 3-year, and 5-year OS rate compared to PLT in living-donor liver transplantation (LDLT) recipients. Moreover, 1-year, 3-year, and 5-year DFS were also superior in SLT compared to PLT in both the DDLT and LDLT recipients. In patients within Milan criteria there were no statistically significant differences in 1-year, 3-year, and 5-year OS and DFS between the SLT group and the PLT group. Similarly, in patients beyond Milan criteria, both SLT and PLT showed no significant difference for 1-year, 3-year, and 5-year OS rate. Our meta-analysis included the largest number of studies comparing SLT and PLT, and SLT was found to have significantly better OS and DFS. Moreover, this meta-analysis suggests that SLT has comparable postoperative complications to that of PLT, and thus, SLT may be a better treatment strategy for recurrent HCC patients and patients with compensated liver, whenever feasible, considering the severe organ limitation and the safety of SLT. However, PLT can be referred as a treatment strategy for HCC patients with cirrhotic and decompensated liver.