Zonulin has previously been related to intestinal permeability in various inflammatory diseases, and more recently to the physiopathology of severe COVID-19 infections. We analysed serum samples from a previous study of a Peruvian cohort of hospitalised COVID-19 patients, for the quantification of zonulin by sandwich ELISA. Comparisons with clinical data, haematological and biochemical parameters and cytokine/chemokine levels were made. We found higher baseline zonulin levels in deceased patients, and zonulin was associated with fatal outcome in multivariable analyses, even after adjustment for age, gender, and obesity. There were also positive correlations between zonulin, creatinine, D-dimer values and prothrombin time, while inverse correlations were found for Sa/FiO₂ ratio and CCL5 (RANTES). Further longitudinal studies are recommended to analyse the variation of zonulin levels over time as well as their relationship with long-COVID.

Innate immune responses through the production of type I interferon-α (anti-IFN-α) play an essential role in the defense against viruses. The autoantibodies (auto-Abs) anti-IFN-α are implicated in COVID-19 pathogenesis with higher levels among patients with worse prognoses. The study aimed to assess the levels of anti-IFN-α auto-Abs in Peruvian patients with severe/critical hospitalized COVID-19 compared to asymptomatic/mild COVID-19 outpatients and healthy controls. We analyzed 101 serum samples, including 56 (55.5%) severe/critical, 13 (12.3%) asymptomatic/mild COVID-19 patients, and 32 (32.2%) healthy controls, which we tested using a commercial ELISA anti-IFN-α-auto-Abs kit. We observed seropositivity of 48.2% (26/54) to anti-IFN-α auto-Abs among the severe/critical COVID-19 group, but 0% (0/13) and 3.1% (1/32) among the asymptomatic/mild COVID-19 and healthy groups (P = 0.021), respectively. Furthermore, we observed a significant association between the log₁₀ of anti-IFN-α auto-Abs and the COVID-19 status, with the log₁₀ of anti-IFN-α auto-Abs levels being significantly higher among the severe/critical COVID-19 group compared to the healthy controls (β = 1.20; confidence interval [95% CI]: 0.72–1.67; P < 0.001). Such association remains significant either when adjusted by age and gender (adjusted β = 1.16; 95% CI: 0.62–1.70; P < 0.001) and when adjusted by the subjects' age, gender, and obesity (adjusted β = 1.16; 95% CI: 0.62–1.70; P < 0.001). Despite not measuring neutralizing activity, this study highlights the high frequency of these auto-Abs in the Peruvian population with a worse prognosis of COVID-19.

Background: The blaSCO-1 gene, which codes for a carbenicillinase, is an uncommon β-lactamase. To the best of our knowledge, we report the first instance of a Klebsiella pneumoniae clinical high-risk isolate carrying blaSCO-1 in Peru. Objectives: To characterize a K. pneumoniae clinical isolate carrying blaSCO-1 in Peru, isolated from a tertiary care hospital in Lima, Peru. Methods: Susceptibility to amoxicillin/clavulanic acid, amoxicillin/sulbactam, piperacillin/tazobactam, aztreonam, ceftriaxone, cefotaxime, ceftazidime, ceftazidime/avibactam, cefepime, imipenem, meropenem, ciprofloxacin, trimethoprim/sulfamethoxazole, gentamicin, amikacin and tigecycline was determined using the Kirby–Bauer disc diffusion method. Detection of blaSCO-1 was established by Illumina WGS and bioinformatic analyses. All the publicly available genomes from K. pneumoniae carrying blaSCO-1 from the American continent were downloaded from the NCBI Isolates browser for assessment of phylogenetic comparisons. Results: The isolate showed resistance to all the tested antibiotics except for ceftazidime/avibactam, carbapenems and tigecycline. Illumina WGS showed the presence of blaSCO-1 and blaOXA-1, blaSHV-28, blaTEM-1, blaCTX-M-15, as well as genes associated with resistance to quinolones, fosfomycin, aminoglycosides, sulphonamides, trimethoprim and phenicols. Moreover, the isolate was ST307, a high-risk clone of K. pneumoniae usually associated with blaCTX-M-15 and/or carbapenemases. Notwithstanding, the latter were not found on this isolate. Phylogenetic relationships were established by comparisons with 19 K. pneumoniae genomes carrying blaSCO-1 from other countries in the Americas, revealing at least three different clades. Conclusions: This study highlights the importance of genomic surveillance of uncommon antimicrobial resistance genes such as blaSCO-1, which might contribute to further antimicrobial resistance levels in this country.

Acinetobacter baumannii is an opportunistic pathogen of great clinical concern, showing high levels of resistance to several antimicrobials, including carbapenems. This study aimed to characterize carbapenem-resistant A. baumannii recovered from a tertiary care hospital (Lima, Peru) in January–February 2021 (during the coronavirus disease 2019 pandemic). Antimicrobial susceptibility was determined by VITEK-2, and the presence of carbapenem-resistance genes by PCR. All 40 A . baumannii isolates were extensively drug-resistant, showing full resistance to all antibiotics tested except ampicillin/sulbactam (95% of resistance) and colistin (10%). The bla _OXA-24-like gene was detected in 90% of isolates, and the remaining 10% isolates harbored the bla _OXA-23-like gene. Pulsed-field gel electrophoresis classified isolates into three different pulsotypes, grouping 8, 2, and 30 isolates, respectively. Additionally, whole-genome sequencing of two isolates of the main pulsotype revealed that they belonged to ST2 and ST2724 (international clone II) and harbored the bla _TEM-1 , bla _OXA-66 , bla _OXA-72 , and bla _ADC-30 β-lactamase genes; mutations in gyrA and parC , aminoglycoside, tetracycline, and sulfonamide resistance genes; and a class 1 integron (In439) containing aac(6′)-Ib′ , catB8 , and aadA1 located inside the AbGRI3 genomic resistance island. These findings highlight the presence of highly resistant and clonally related ST2 of A. baumannii and their relationship with genomes of ST2 of South America. IMPORTANCE: Acinetobacter baumannii is a critical pathogen known for causing severe infections in hospitalized patients and for its remarkable ability to develop resistance to multiple antibiotics, including last-line treatments such as carbapenems. In Latin America, data on the genetic background and spread of these resistant strains remain limited. Our study provides a detailed molecular and genomic characterization of extensively drug-resistant A. baumannii isolates collected from a Peruvian hospital during the coronavirus disease 2019 pandemic. We identified a predominant clone belonging to international clone II, which carried multiple resistance genes and a complex resistance island. These findings raise public health concerns, as they highlight the silent spread of high-risk clones in regions with limited surveillance capacity. By contributing valuable local genomic data, our study supports global efforts to track antimicrobial resistance and underscores the urgent need to strengthen molecular monitoring of hospital-associated pathogens also in low- and middle-income countries.

Acinetobacter spp. are often isolated from natural sources, but knowledge about their presence in wild animals is fragmented and uncomplete. The present study aimed to characterize a series of Acinetobacter radioresistens isolated from Humboldt penguins (Spheniscus humboldti). Fifteen Humboldt penguins from an inhabited northern Peruvian island were sampled. Microorganisms were identified by MALDI-TOF MS. Antibiotic susceptibility to 12 antimicrobial agents was established, and clonal relationships were determined. A representative isolate was selected for whole genome sequencing (WGS). A. radioresistens were isolated from the feces of 12 (80%) Humboldt penguins, being susceptible to all the antimicrobial agents tested, except eight cefotaxime-intermediate isolates. All A. radioresistens were clonally related. WGS showed that the isolate belonged to ST1972, the presence of two chromosomal encoded carbapenemases (blaOXA-23 and a putative subclass B3 metallo-β-lactamase), and a series of point mutations in antibiotic-resistance related chromosomal genes, which were considered as polymorphisms. In addition, a few virulence factors, including a capsule-encoding operon, superoxide dismutases, catalases, phospholipases and a siderophore receptor were identified. The present results suggest that A. radioresistens may be a common member of the gut microbiota of Humboldt penguins, but further studies in other geographical areas are needed to establish this finding.