Prevalence and Molecular Mechanisms of Carbapenem-Resistant Klebsiella pneumoniae Isolated from Bloodstream Infections

International Journal of Medicine and Medical Sciences | Vol. 12, No. 2, February 2022 | pp. 9–16

DOI: 10.46882/2022/IJMMS/120009

Original Research Article

Prevalence and Molecular Mechanisms of Carbapenem-Resistant Klebsiella pneumoniae Isolated from Bloodstream Infections

Samuel T. Balogun¹, Chidi O. Emmanuel², Fatima B. Yusuf¹*

¹Department of Medical Microbiology, College of Health Sciences, University of Ilorin, Ilorin, Nigeria.

²Department of Chemical Pathology, University College Hospital, Ibadan, Nigeria.

Abstract:

Bloodstream infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) present serious clinical challenges due to limited therapeutic options and high mortality rates. This prospective cross-sectional study investigated the prevalence, antibiotic susceptibility profiles, and molecular carbapenemase genotypes of K. pneumoniae isolated from patients with blood cultures matching clinical sepsis criteria. Stool and blood culture specimens collected from 450 hospitalized patients were screened. Isolates were identified using standard biochemical methods, and carbapenem resistance was confirmed via meropenem disk diffusion testing. Carbapenemase-producing genes (blaKPC, blaNDM, and blaOXA-48) were identified using multiplex PCR amplification. Out of 120 laboratory-confirmed K. pneumoniae bloodstream isolates, the prevalence of CRKP was found to be 18.3% (22/120). Phenotypic profiles showed high co-resistance rates to amikacin (72.7%) and ciprofloxacin (86.4%), while all strains remained susceptible to polymyxin B and tigecycline (100%). Molecular analysis revealed that the blaNDM gene was the most common genotype (59.1%), followed by blaOXA-48 (27.3%) and blaKPC (9.1%), with multiple carbapenemase genes found in 4.5% of the isolates. Logistic regression modeling demonstrated that a prior ICU stay > 7 days (OR = 4.1, 95% CI = 2.0–8.4, p < 0.001) and previous treatment with third-generation cephalosporins (OR = 3.2, p < 0.01) were independent risk factors for CRKP infection. The high burden of NDM-producing K. pneumoniae strains highlights the importance of implementing strict contact isolation precautions and antimicrobial stewardship programs in tertiary hospitals.

Keywords: Klebsiella pneumoniae, Bloodstream Infection, Carbapenem Resistance, blaNDM gene, Carbapenemase, Antimicrobial Stewardship

Manuscript Timeline: Received: October 10, 2021; Revised: November 18, 2021; Accepted: December 14, 2021; Published: February 17, 2022.

Citation: Balogun ST, Emmanuel CO, Yusuf FB. Prevalence and Molecular Mechanisms of Carbapenem-Resistant Klebsiella pneumoniae Isolated from Bloodstream Infections. International Journal of Medicine and Medical Sciences, 2022, 12(2): 9–16. DOI: 10.46882/2022/IJMMS/120009

International Journal of Medicine and Medical Sciences | Vol. 12, No. 3, March 2022 | pp. 17–24

DOI: 10.46882/2022/IJMMS/120017

Original Research Article

Gastroprotective and Antiperoxidative Actions of Zingiber officinale Extract against Indomethacin-Induced Gastric Ulceration in Wistar Rats

Amina R. Abubakar¹, George K. Mwangi², Thomas O. Adeyemi¹*

¹Department of Medical Biochemistry, Faculty of Basic Medical Sciences, Bayero University, Kano, Nigeria.

²Department of Pharmacology, School of Pharmacy, Makerere University, Kampala, Uganda.

Abstract:

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin often induce gastric mucosal damage through the generation of reactive oxygen species and lipid peroxidation. This experimental animal study examined the gastroprotective and antiperoxidative potential of a methanolic extract of Zingiber officinale rhizome (MEZO) against indomethacin-induced gastric ulceration in male Wistar rats. Thirty adult rats were randomly assigned to five groups: Control, Indomethacin-alone (30 mg/kg, orally as a single dose on day 14), Omeprazole reference control (20 mg/kg), and two treatment groups receiving MEZO (200 and 400 mg/kg) orally for 14 consecutive days prior to indomethacin administration. Gastric mucosal injury was evaluated using macroscopic ulcer indices, gastric wall mucus quantification, lipid peroxidation assays, and histopathological analysis. Administration of indomethacin caused severe gastric ulceration, evidenced by a high mean ulcer index (4.82 ± 0.35) and a significant reduction in gastric wall mucus content (p < 0.01). Indomethacin also significantly increased tissue malondialdehyde (MDA) levels and reduced glutathione (GSH) and superoxide dismutase (SOD) activities in the gastric mucosa (p < 0.01). Pre-treatment with MEZO (especially at 400 mg/kg) significantly protected against mucosal injury, lowering the mean ulcer index to 1.24 ± 0.15 (p < 0.01 vs. indomethacin group) and preserving gastric wall mucus. MEZO lowered lipid peroxidation and restored antioxidant enzyme activities. Histopathological evaluation confirmed these findings, showing minimal mucosal erosion and reduced inflammatory cell infiltration. Zingiber officinale extract offers substantial protection against indomethacin-induced gastric ulceration by reducing oxidative stress and preserving mucosal integrity.

Keywords: Zingiber officinale, Indomethacin, Gastric Ulcer, Lipid Peroxidation, Gastroprotection, Antioxidants

Manuscript Timeline: Received: November 12, 2021; Revised: December 20, 2021; Accepted: January 15, 2022; Published: March 11, 2022.

Citation: Abubakar AR, Mwangi GK, Adeyemi TO. Gastroprotective and Antiperoxidative Actions of Zingiber officinale Extract against Indomethacin-Induced Gastric Ulceration in Wistar Rats. International Journal of Medicine and Medical Sciences, 2022, 12(3): 17–24. DOI: 10.46882/2022/IJMMS/120017

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