Nischal Ranganath

Dr. Nischal Ranganath


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 January 2023 in Open Forum Infectious Diseases
Verified
Journal Article
Open access
PDF file
MUMeritxell Urtecho
Meritxell Urtecho
VRVictor D Torres Roldan
Victor D Torres Roldan
TNTarek Nayfeh
Tarek Nayfeh
NSNataly R Espinoza Suarez
Nataly R Espinoza Suarez
NRNischal Ranganath
Nischal Ranganath
JOJohn C O’hOro
John C O’hOro
Background: Peripherally inserted central catheters (PICCs) and midlines are commonly used devices for reliable vascular access. Infection and thrombosis are the main adverse effects of these catheters. We aimed to evaluate the relative risk of complications from midlines and PICCs. Methods: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies. The primary outcomes were catheter-related bloodstream infection (CRBSI) and thrombosis. Secondary outcomes evaluated included mortality, failure to complete therapy, catheter occlusion, phlebitis, and catheter fracture. The certainty of evidence was assessed using the GRADE approach. Results: Of 8368 citations identified, 20 studies met the eligibility criteria, including 1 RCT and 19 observational studies. Midline use was associated with fewer patients with CRBSI compared with PICCs (odds ratio [OR], 0.24; 95% CI, 0.15–0.38). This association was not observed when we evaluated risk per catheter. No significant association was found between catheters when evaluating risk of localized thrombosis and pulmonary embolism. A subgroup analysis based on location of thrombosis showed higher rates of superficial venous thrombosis in patients using midlines (OR, 2.30; 95% CI, 1.48–3.57). We did not identify any significant difference between midlines and PICCs for the secondary outcomes. Conclusions: Our findings suggest that patients who use midlines might experience fewer CRBSIs than those who use PICCs. However, the use of midline catheters was associated with greater risk of superficial vein thrombosis. These findings can help guide future cost-benefit analyses and direct comparative RCTs to further characterize the efficacy and risks of PICCs vs midline catheters.

1 October 2017 in Cytokine & Growth Factor Reviews
Verified
Journal Article
Open access
TSTeslin Sandstrom
Teslin Sandstrom
NRNischal Ranganath
Nischal Ranganath
JAJonathan B. Angel
Jonathan B. Angel
By interfering with the type I interferon (IFN1) response, human immunodeficiency virus 1 (HIV-1) can circumvent host antiviral signalling and establish persistent viral reservoirs. HIV-1-mediated defects in the IFN pathway are numerous, and include the impairment of protein receptors involved in pathogen detection, downstream signalling cascades required for IFN1 upregulation, and expression or function of key IFN1-inducible, antiviral proteins. Despite this, the activation of IFN1-inducible, antiviral proteins has been shown to facilitate the killing of latently HIV-infected cells in vitro. Understanding how IFN1 signalling is blocked in physiologically-relevant models of HIV-1 infection, and whether these defects can be reversed, is therefore of great importance for the development of novel therapeutic strategies aimed at eradicating the HIV-1 reservoir.

28 July 2023 in American Journal of Transplantation
Verified
Journal Article
Open access
EHEibhlin Higgins
Eibhlin Higgins
NRNischal Ranganath
Nischal Ranganath
OMOmar Mehkri
Omar Mehkri
AMAneela Majeed
Aneela Majeed
JWJeremey Walker
Jeremey Walker
RRRaymund R. Razonable
Raymund R. Razonable
In 2022 the largest global outbreak of mpox to date emerged. In the immunocompetent host, mpox is generally presents as a self-limiting illness. However immunosuppression such as that seen with advanced human immunodeficiency virus (HIV) has been associated with significant morbidity and mortality related to mpox infection. To evaluate the impact of immunosuppression related to solid organ transplantation on clinical features and outcomes of mpox we established a multicenter case registry. 11 cases from 7 participating centers in the USA were submitted. All cases occurred in males. The majority were kidney transplant recipients (91%, n=10). Median duration of symptoms at presentation was 6 days (range 3-14 days). Rates of hospitalization were high (73%, n=8) with a median length of stay of 4.5 days (range 1-10). Mpox in solid organ transplant recipients (SOTRs) was associated with a high burden of skin lesions and systemic symptoms. Fever, fatigue, pharyngitis and proctitis were commonly reported. Other clinical features included headache, myalgia, epididymorchitis, urinary retention, hemetemesis, pneumonitis and circulatory shock. All patients received treatment with tecovirimat. There was one mpox related mortality in the cohort. Infection was reported to have resolved at 30 day follow up in all other cases.

8 October 2025 in Journal of Clinical Microbiology
Verified
Journal Article
Open access
DBDavid R. Bayless
David R. Bayless
MDMitchell Dumais
Mitchell Dumais
JMJack McHugh
Jack McHugh
NRNischal Ranganath
Nischal Ranganath
MFMadiha Fida
Madiha Fida
OSOmar M. Abu Saleh
Omar M. Abu Saleh
Achromobacter species are Gram-negative bacilli that predominantly affect individuals with cystic fibrosis or those with immunocompromising conditions. Clinical and microbiologic data on Achromobacter species are limited due to the rarity of these organisms and challenges with species-level identification. We conducted a 10-year retrospective analysis (1 January 2013 to 14 March 2023) of all bloodstream and non-bloodstream Achromobacter isolates identified at three tertiary-care Mayo Clinic locations (Minnesota, Arizona, and Florida). Additionally, we examined clinical characteristics of adult patients with Achromobacter bloodstream isolates. A total of 1,598 Achromobacter isolates, encompassing 1,545 non-bloodstream isolates and 53 bloodstream isolates, were identified. The most frequently identified species was Achromobacter xylosoxidans , though species-level identification was not possible for many isolates. Among adult patients with Achromobacter bloodstream infection, the mean age was 58.3 years (standard deviation ± 16.7), 73.1% had a central venous catheter, and 59.6% were immunocompromised. All-cause mortality was 10.2% at 30 days and 18.4% at 90 days. Bloodstream isolates exhibited greater than 90% susceptibility to meropenem, piperacillin-tazobactam, and trimethoprim-sulfamethoxazole. The respiratory tract was the most common source of non-bloodstream isolates (57.5%). Non-bloodstream isolates showed high susceptibility to imipenem (94.6%), piperacillin-tazobactam (92.8%), trimethoprim-sulfamethoxazole (92.1%), and meropenem (87.5%) while demonstrating significant resistance to fluoroquinolones and aminoglycosides. Our findings support the use of piperacillin-tazobactam, carbapenems, or trimethoprim-sulfamethoxazole as initial therapy for Achromobacter infections. Further research is needed to better define the clinical and microbiologic characteristics of Achromobacter infections. IMPORTANCE: Achromobacter is a rare but important genus of bacteria that tends to cause infection in those with cystic fibrosis, recurrent healthcare exposures, and/or an immunocompromising condition. There is limited data on the clinical profile of Achromobacter infections as well as optimal antibiotic selection for affected patients. We conducted a retrospective study to improve understanding of the microbiologic and clinical characteristics of Achromobacter . Our study consists of a 10-year survey of all Achromobacter isolates processed by three Mayo Clinic tertiary-care centers in Minnesota, Florida, and Arizona from 2013 to 2023. We report multiple findings, including the clinical characteristics of patients with Achromobacter bloodstream infection, the number of different Achromobacter species identified, and the sources of isolates not obtained from blood cultures. We additionally present antimicrobial susceptibility results for Achromobacter isolates. Our study provides guidance to clinicians treating Achromobacter infections and, it is hoped, will facilitate ongoing study of Achromobacter .

16 August 2022 in Mayo Clinic Proceedings
Verified
Journal Article
Closed access
NRNischal Ranganath
Nischal Ranganath
PTPritish K. Tosh
Pritish K. Tosh
JOJohn O’hOro
John O’hOro
PSPriya Sampathkumar
Priya Sampathkumar
MBMatthew J. Binnicker
Matthew J. Binnicker
ASAditya S. Shah
Aditya S. Shah

13 March 2024 in Journal of Clinical Microbiology
Verified
Journal Article
Closed access
NRNischal Ranganath
Nischal Ranganath
MMMaria Alejandra Mendoza
Maria Alejandra Mendoza
RSRyan Stevens
Ryan Stevens
DKDalton Kind
Dalton Kind
Nancy WengenackNancy Wengenack
Nancy Wengenack
ASAditya Shah
Aditya Shah
Rhodococcus equi is an opportunistic pathogen known to cause pulmonary and extrapulmonary disease among immunocompromised patients. Treatment is frequently challenging due to intrinsic resistance to multiple antibiotic classes. While non- equi Rhodococcus spp. are prevalent, their clinical significance is poorly defined. There is also limited data on antibiotic susceptibility testing (AST) of Rhodococcus infection in humans. We conducted a single-center, retrospective cohort study evaluating clinical characteristics, microbiologic profile, and AST of Rhodococcus infections between June 2012 and 2022 at our tertiary academic medical center. Identification of Rhodococcus spp. was performed by Sanger 16S rRNA gene sequencing and/or matrix-assisted laser desorption ionization-time of flight mass spectrometry, and AST was performed by agar dilution. Three hundred twenty-two isolates of Rhodococcus spp. were identified from blood (50%), pulmonary (26%), and bone/joint (12%) sources. R. equi/hoagii, R. corynebacterioides , and R. erythropolis were the most frequently isolated species, with 19% of isolates identified only to genus level. One hundred ninety-nine isolates evaluated for AST demonstrated high-level resistance to amoxicillin/clavulanate, cephalosporins, and aminoglycosides. More than 95% susceptibility to imipenem, vancomycin, linezolid, rifampin, and clarithromycin was observed. Non- equi species showed a significantly more favorable AST profile relative to R. equi . Clinically significant Rhodococcus infection was rare with 10 cases diagnosed (majority due to R. equi ) and managed. The majority of patients received 2- or 3-drug combination therapy for 2–6 months, with favorable clinical response. Significant differences in AST were observed between R. equi and non- equi species. Despite high antimicrobial resistance to several antibiotic classes, imipenem and vancomycin remain appropriate empiric treatment options for R. equi . Future research evaluating mechanisms underlying antimicrobial resistance is warranted.