Epidemiology and mortality outcome of carbapenem- and colistin-resistant Klebsiella pneumoniae, Escherichia coli, Acinetobacter baumannii, and Pseudomonas aeruginosa bloodstream infections

BACKGROUND

Bloodstream infections caused by carbapenem-resistant Gram-negative bacteria represent a major therapeutic challenge to clinicians worldwide. This study examined the epidemiology of carbapenem and colistin resistance in Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii blood isolates in an academic institution in Oman.

METHODS

Adult patients with bloodstream infections caused by Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii, between January 1, 2017, and December 31, 2020, were identified. Rates of carbapenem resistance, carbapenem-colistin dual resistance, and 30-day all-cause mortality were examined.

RESULTS

585 non-repeat bloodstream infections due to Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii were identified during the study period. OXA-48 was the most prevalent carbapenemase gene in carbapenem-resistant K. pneumoniae blood isolates. Carbapenem resistance was observed in 160 (27.7%) of blood isolates, with 131 (81.9%) of these being healthcare-onset cases. Carbapenem resistance was highest in Acinetobacter baumannii (80.4%), followed by Klebsiella pneumoniae (46.4%), and Pseudomonas aeruginosa (29.9%). Sixteen (13.4%) of the carbapenem-resistant blood isolates were found to be colistin resistant. Thirty-day all-cause mortality was 68.1% in patients with bloodstream infections caused by carbapenem-resistant isolates, versus 21.3% in patients with bloodstream infections caused by carbapenem-susceptible isolates.

CONCLUSION

The prevalence of carbapenem resistance and carbapenem-colistin dual resistance in Gram-negative blood culture isolates from patients with bloodstream infections is unacceptably high. Patients with bloodstream infections due to carbapenem-resistant isolates had substantially higher mortality.

Anakinra in hospitalized patients with severe COVID-19 pneumonia requiring oxygen therapy: Results of a prospective, open-label, interventional study

Objective

The aim of this study was to evaluate the efficacy of anakinra in patients who were admitted to hospital for severe COVID-19 pneumonia requiring oxygen therapy.

Methods

A prospective, open-label, interventional study in adults hospitalized with severe COVID-19 pneumonia was conducted. Patients in the interventional arm received subcutaneous anakinra (100 mg twice daily for 3 days, followed by 100 mg daily for 7 days) in addition to standard treatment. Main outcomes were the need for mechanical ventilation and in-hospital death. Secondary outcomes included successful weaning from supplemental oxygen and change in inflammatory biomarkers. Outcomes were compared with those of historical controls who had received standard treatment and supportive care.

Results

A total of 69 patients were included: 45 treated with anakinra and 24 historical controls. A need for mechanical ventilation occurred in 14 (31%) of the anakinra-treated group and 18 (75%) of the historical cohort (p < 0.001). In-hospital death occurred in 13 (29%) of the anakinra-treated group and 11 (46%) of the historical cohort (p = 0.082). Successful weaning from supplemental oxygen to ambient air was attained in 25 (63%) of the anakinra-treated group compared with 6 (27%) of the historical cohort (p = 0.008). Patients who received anakinra showed a significant reduction in inflammatory biomarkers.

Conclusion

In patients with severe COVID-19 pneumonia and high oxygen requirement, anakinra could represent an effective treatment option and may confer clinical benefit.

Trial registration number

ISRCTN74727214.

Relapse of herpes simplex encephalitis in a patient with metastatic small cell lung cancer following scalp sparing whole brain radiotherapy

Herpes simplex virus is the most common cause of severe and potentially fatal sporadic encephalitis worldwide. Recurrence of neurologic symptoms after resolution of the initial episode of HSV encephalitis and despite adequate treatment with intravenous acyclovir is well recognized albeit rare. Most of these recurrences had no evidence of replicating virus and are immune in nature with only a minority of these recurrences representing true virologic relapses. Immunocompromised patients are predominantly at greater risk for virologic relapse of HSV encephalitis with potentially severe and at times fatal consequences. We describe a patient with small cell lung cancer and brain metastasis who underwent chemotherapy, treatment with dexamethasone and whole brain radiotherapy who subsequently suffered two episodes of HSV encephalitis three months and seven months after completion of radiotherapy and while on dexamethasone treatment.

Gastrointestinal basidiobolomycosis: Beware of the great masquerade a case report

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We describe a previously healthy young patient with gastrointestinal basidiobolomycosis misdiagnosed as colonic malignancy.

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This is the first reported case in an adult patient from Oman suggesting that the disease is possibly under-recognized.

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Acquaintance with this exceptionally rare infection is critical for successful clinical outcome.

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Azoles are effective anti-fungal therapy for gastrointestinal basidiobolomycosis.

Basidiobolomycosis is rare infection caused by the saprophytic fungus Basidiobolus ranarum. Gastrointestinal basidiobolomycosis is an infrequent, albeit, increasingly reported, emerging form of the disease and typically affects immunocompetent individuals with potentially grave sequelae if unrecognized. Acquaintance with this exceptionally rare fungus and its potential for presenting as gastrointestinal mass masquerading as colonic malignancy is critical for timely diagnosis, appropriate treatment and successful clinical outcome.

We report a case of gastrointestinal basidiobolomycosis masquerading as colonic malignancy in a 29-year-old Omani patient successfully treated with combination of surgery and prolonged azole antifungal therapy.

Erysipelothrix rhusiopathiae endocarditis diagnosed by broad range 16s rRNA PCR gene sequencing

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Occupationally related E. rhusiopathiae endocarditis requiring valve replacement surgery.

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Broad range 16S rRNA PCR applied to excised valve leaflets/vegetations confirmed the presence of E. rhusiopathiae.

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E. rhusiopathiae should be included in the list of pathogens causing endocarditis especially when occupational setting is compatible.

Erysipelothrix rhusiopathiae (E. rhusiopathiae) is a rare occupational opportunistic Gram-positive bacillus. Infections caused by E. rhusiopathiae are principally a sequel of occupational and recreational exposures to infected animals. Infective endocarditis is a classic, albeit it infrequent, manifestation of invasive infection with this bacterium.

We present a case of E. rhusiopathiae mitral valve endocarditis in a farmer with psoriasis presented with acute intractable heart failure requiring valve replacement surgery. E. rhusiopathiae was identified by 16S rRNA-based gene sequencing from culture-negative, surgically excised mitral valve leaflets.

Disseminated strongyloidiasis complicated by alveolar hemorrhage, meningitis, and septic shock treated with albendazole and subcutaneous ivermectin

The case of a patient with disseminated strongyloidiasis following chemotherapy for lymphoplasmacytic lymphoma is presented.

Prevalence and 30-day all-cause mortality of carbapenem-and colistin-resistant bacteraemia caused by Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae: Description of a decade-long trend

BACKGROUND

Bacteraemia due to carbapenem-resistant gram-negative bacteria is challenging. This study examined the burden of carbapenem and colistin resistance in Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii bacteraemia in Oman.

METHODS

Adult patients admitted to Sultan Qaboos University Hospital between January 1, 2007 and December 31, 2016 with positive blood cultures for P. aeruginosa, A. baumannii, or K. pneumoniae were identified. Rates of carbapenem resistance, trends in prevalence, and 30-day all-cause mortality were examined.

RESULTS

Two hundred and twenty-seven (29.8%) of 761 bacteraemia cases due to these three isolates were carbapenem-resistant, with 87.2% being healthcare-associated. A. baumannii caused 52% of all carbapenem-resistant bacteraemia, K. pneumoniae caused 30%, and P. aeruginosa caused 18%. Rates of carbapenem resistance in P. aeruginosa, A. baumannii, and K. pneumoniae bacteraemia increased from 20%, 67%, and 0%, respectively, in 2007 to 25%, 86%, and 35%, respectively, in 2016. Seventeen (7.9%) carbapenem-resistant bacteraemia cases were also colistin-resistant. Thirty-day all-cause mortality was 62% in patients with carbapenem-resistant bacteraemia and 22% in patients with carbapenem-sensitive bacteraemia.

CONCLUSIONS

The prevalence of carbapenem-resistant K. pneumoniae, A. baumannii, and P. aeruginosa bacteraemia is increasing alarmingly in Oman, with a large proportion of K. pneumoniae and P. aeruginosa demonstrating additional resistance to colistin. Patients with carbapenem-resistant bacteraemia had higher 30-day all-cause mortality.

Frequency of TLR4 (1063A/G and 1363C/T) polymorphisms in healthy and HIV-infected Omani individuals and their relationship to viral load and T cell count

Toll-like receptors (TLRs) are essential elements of the innate immune response to different infections including the infection with human immunodeficiency virus (HIV). Single nucleotide polymorphisms (SNPs) in TLRs such as TLR4 1063A/G and 1363C/T have been found to be associated with changes in CD4 count, viral load (VL), and disease progression during HIV infection. However, the association of these SNPs with the pathogenesis during HIV infection is controversial. We investigated the frequency of TLR4 1063A/G and 1363C/T SNPs in 168 Omani donors [68 HIV-infected patients (>3% of Omani HIV-infected patients) and 100 healthy controls] and the association of these SNPs with the VL, CD8 and CD4 counts, and the immune recovery after cART as observed by CD4 T cell increase. SNPs were analyzed after the amplification of the regions that contain them by polymerase chain reaction (PCR) and sequencing of the PCR products. The TLR4 1063GG genotype was detected in the HIV-infected group only. No association was found between the studied SNPs and the average VL during 1 year of infection, the average CD4 and CD8 count during 1 year of viremia, the nadir CD4 count, the CD4 count when the patient reached VL < 50 copies/mL due to cART, and the ratio of the CD4 count 3 and 6 months after reaching VL < 50 copies/mL after cART to the last CD4 count before reaching VL < 50 copies/mL. Our study suggests that TLR4 (1063A/G and 1363C/T) SNPs have no association with the VL or the CD4 and CD8 counts during HIV infection.

Association of single-nucleotide polymorphisms in TLR7 (Gln11Leu) and TLR9 (1635A/G) with a higher CD4T cell count during HIV infection

BACKGROUND

Toll-like receptors (TLRs) are essential elements of the innate immune response to different infections including HIV-1 infection. The single-nucleotide polymorphisms (SNPs) in TLRs have been associated with CD4T cell count and HIV disease progression. The TLR7 (Gln11Leu) SNP was shown to be associated with a rapid decline of CD4T cell count. A relation between TLR9 (1635A/G) SNP and CD4T cells count in HIV-infected patients is suggested, although the outcome associated with this SNP is still controversial.

OBJECTIVES

To determine the relation of the TLR7 (Gln11Leu) and TLR9 (1635A/G) SNPs with the damage to the immune system during HIV infection as reflected by the average CD4T cell count.

METHODS

A total of 63 HIV-infected patients and 100 healthy individuals (controls) were enrolled in this study. The above named SNPs were analyzed after amplification of the regions that potentially contain the SNPs by polymerase chain reaction (PCR) and sequencing of the PCR products. The frequency of these SNPs and their relation with the CD4T cell count were investigated.

RESULTS

The TLR7 (AA) genotype 'Gln' had a trend toward being associated with a CD4T cell count >400cells/μl after controlling viremia via HAART. Additionally, the TLR9 1635 (GG) genotype was associated with a low average CD4T cell count and the TLR9 1635 (AG) genotype was significantly related to a higher average CD4T cell count during the viremic period in HIV-infected patients.

CONCLUSION

The results of this longitudinal study supports the presence of an association between the TLR9 (1635A/G) genotype and the CD4T cell count, which helps clarifying the controversial results regarding this association. It also suggests that the CD4T cell count during the viremic period might be linked to the combination of both TLR7 (Gln11Leu) and TLR9 (1635A/G) genotypes. These results may help predicting the damage to the immune system, and thus impacting the planning for novel anti-HIV strategies.