Planktonic and biofilm states of Staphylococcus aureus isolated from bone and joint infections and the in vitro effect of orally available antibiotics.

AIMS: To demonstrate the in vitro activity of orally available antibiotics against Staphylococcus aureus isolated from bone or orthopedic implant materials. The biofilm eradication of the combination of three antibiotics was also assessed. METHODS AND RESULTS: Clinical isolates from orthopedic infection samples were collected, and S. aureus isolates were classified according to their biofilm production and composition. Almost all S. aureus isolates (n = 36, 97.3%) produced biofilm and the major biofilm components were polysaccharides. Antimicrobial susceptibility was determined in planktonic (minimal inhibitory concentration; MIC) and biofilm cells (minimal biofilm eradication concentration; MBEC) using the MBEC Calgary Device. Overall, the MBEC ranged higher than the MIC. When combined at borderline-susceptible concentrations, moxifloxacin-rifampin and doxycycline-rifampin were both able to eradicate biofilms in a third of the strains whereas the doxycycline-moxifloxacin combination proved ineffective at eradicating biofilm, inhibiting it only in three strains. CONCLUSIONS: We propose rifampin in combination with moxifloxacin or doxycycline for the design of clinical trials of bone and/or orthopedic device infection without proper debridement or material retention.

Association of the Interleukin 1B-31*C Proinflammatory Allele with the Severity of COVID-19 Patients: A Preliminary Report.

Individuals with no known comorbidities or risk factors may develop severe coronavirus disease 2019 (COVID-19). The present study assessed the effect of certain host polymorphisms and viral lineage on the severity of COVID-19 among hospitalized patients with no known comorbidities in Mexico. The analysis included 117 unrelated hospitalized patients with COVID-19. Patients were stratified by whether they required intensive care unit (ICU) admission: the ICU group (n = 40) and non-ICU group (n = 77). COVID-19 was diagnosed on the basis of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription-polymerase chain reaction (RT-PCR) assay and clinical and radiographic criteria. The presence of the IL1B-31 (T/C) polymorphism was determined for all patients using PCR and nucleotide sequencing. Genotyping of the IL-4 (-590, T/C) and IL-8 (-251, T/A) polymorphisms was performed by the amplification refractory mutation system-PCR method. Genotyping of IL1-RN was performed using PCR. Viral genome sequencing was performed using the ARTIC Network amplicon sequencing protocol using a MinION. Logistic regression analysis identified the carriage of IL-1 B*-31 *C as an independent potential risk factor (odds ratio [OR] = 3.1736, 95% confidence interval [CI] = 1.0748-9.3705, p = 0.0366) for ICU admission and the presence of IL-RN*2 as a protective factor (OR = 0.4371, 95% CI = 0.1935-0.9871, p = 0.0465) against ICU admission. Under the codominant model, the CC genotype of IL1B-31 significantly increased the risk of ICU admission (OR: 6.38, 95% CI: 11.57-25.86, p < 0.024). The IL1B-31 *C-IL-4-590 *T haplotype increased the risk of ICU admission (OR = 2.53, 95% CI = 1.02-6.25, p = 0.047). The 42 SARS-CoV-2 genomes sequenced belonged to four clades, 20A-20D. No association was detected between SARS-CoV-2 clades and ICU admission or death. Thus, in patients with no known comorbidities or risk factors, the IL1B-31*C proinflammatory allele was observed to be associated with the risk of ICU admission owing to COVID-19.

Clinical and Immunologic Efficacy of the Recombinant Adenovirus Type-5-Vectored (CanSino Bio) Vaccine in University Professors during the COVID-19 Delta Wave.

Information regarding the efficacy of the recombinant adenovirus type-5-vectored (CanSino Bio) vaccine against the COVID-19 disease in a real-life setting is limited. A retrospective cohort study was carried out in the teaching university community of the metropolitan area of Monterrey, Mexico, through a four-section survey, and during the COVID-19 delta wave. Determination of IgG antibodies against SARS-CoV-2 spike (S) protein was performed in a subset of participants vaccinated with CanSino Bio. A total of 7468 teachers responded to the survey, and 6695 of them were fully vaccinated. Of those, 72.7% had CanSino Bio, 10.3% Pfizer, 8.4% AstraZeneca, 1.2% Moderna, and 2.7% others. Symptomatic breakthrough infections were recorded in those vaccinated with CanSino Bio (4.1%), AstraZeneca (2.1%), and Pfizer (2.2%). No difference was found between CanSino Bio and other vaccines regarding hospitalization, the need for mechanical ventilation, and death. For CanSino Bio recipients, anti-S antibodies were >50 AU/mL in 73.2%. In conclusion, primary breakthrough symptomatic infections were higher in the CanSino vaccinated group compared to other brands. Individuals with a previous infection had higher antibody levels than those who were reinfected and without infection. A boosted dose of CanSino is recommended for those individuals without a previous infection.

Prevalence of SARS-CoV-2 Variants of Concern and Variants of Interest in COVID-19 Breakthrough Infections in a Hospital in Monterrey, Mexico.

SARS-CoV-2 variants of concern (VOCs) or of interest (VOIs) causing vaccine breakthrough infections pose an increased risk to worldwide public health. An observational case-control study was performed of SARS-CoV-2 vaccine breakthrough infections in hospitalized or ambulatory patients in Monterrey, Mexico, from April through August 2021. Vaccination breakthrough was defined as a SARS-CoV-2 infection that occurred any time after 7 days of inoculation with partial (e.g., first dose of two-dose vaccines) or complete immunization (e.g., second dose of two-dose vaccines or single-dose vaccine, accordingly). Case group patients (n = 53) had partial or complete vaccination schemes with CanSino (45%), Sinovac (19%), Pfizer/BioNTech (15%), and AstraZeneca/Oxford (15%). CanSino was administered most frequently in ambulatory patients (p < 0.01). The control group (n = 19) received no COVID-19 vaccines. Among SARS-CoV-2 variants detected by whole-genome sequencing, VOC Delta B.1.617.2 predominated in vaccinated ambulatory patients (p < 0.01) and AY.4 in hospitalized patients (p = 0.04); VOI Mu B.1.621 was detected in four (7.55%) vaccinated patients. SARS-CoV-2 breakthrough infections in our hospital occurred mostly in patients vaccinated with CanSino due to the higher prevalence of CanSino vaccine administration in our population. These patients developed mild COVID-19 symptoms not requiring hospitalization. The significance of this study lies on the detection of SARS-CoV-2 variants compromising the efficacy of local immunization therapies in Monterrey, Mexico.

Baricitinib plus dexamethasone compared to dexamethasone for the treatment of severe COVID-19 pneumonia: A retrospective analysis.

OBJECTIVE: We aimed to analyze clinical outcomes from patients with severe COVID-19 pneumonia that received either baricitinib plus dexamethasone or dexamethasone monotherapy. METHODOLOGY: We performed a retrospective comparative study. Data from hospitalized patients with severe COVID-19 pneumonia (saturation <93%, bilateral pulmonary infiltrates) that were treated with baricitinib plus dexamethasone or dexamethasone were collected. Our primary objective was to compare overall mortality and secondly to compare progression to mechanical ventilation and over infection rates. RESULTS: A total of 793 patients were assessed for inclusion criteria, 596 were excluded and 197 were analyzed for primary outcome: 123 in the baricitinib plus dexamethasone group and 74 in the dexamethasone monotherapy group. The mean age was 59.9 years (SD ± 14.5) and 62.1% (123/197) were male. 42.9% (85/197) of the cases required ICU admission and 25.8% (51/197) underwent invasive mechanical ventilation (IMV). Overall thirty-day mortality was 27.9% (55/197); Mortality was significantly lower in the baricitinib plus dexamethasone group compared to the dexamethasone monotherapy group (20.3% vs 40.5%, P = <.05). There was no difference in hospital acquired infections between both groups. CONCLUSION: Thirty-day mortality was significantly lower in patients with COVID-19 pneumonia treated with baricitinib plus dexamethasone versus dexamethasone monotherapy. No difference was observed in progression to invasive mechanical ventilation and hospital acquired infections.

Discrimination of biofilm-producing Stenotrophomonas maltophilia clinical strains by matrix-assisted laser desorption ionization-time of flight.

Stenotrophomonas maltophilia is a Gram-negative drug-resistant pathogen responsible for healthcare-associated infections. The aim was to search for biomarker peaks that could rapidly detect biofilm production in S. maltophilia clinical isolates obtained from two tertiary care hospitals in Mexico. Isolates were screened for the presence of biofilm-associated genes, in which the fsnR gene was associated with biofilm production (p = 0.047), whereas the rmlA+ genotype was associated with the rpfF- genotype (p = 0.017). Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectra comparison yielded three potential biomarker peaks (4661, 6074, and 6102 m/z) of biofilm-producing rmlA+ and rpfF- genotypes with >90% sensitivity (p<0.001). MALDI-TOF MS analyses showed a correlation between the relative abundance of 50S ribosomal proteins (L30 and L33) and the presence of the fnsR, rmlA and rpfF-2 genes, suggested to play a role in biofilm formation. Isolates obtained in the intensive care unit showed low clonality, suggesting no transmission within the hospital ward. The detection of biomarkers peaks by MALDI-TOF MS could potentially be used to early recognize and discriminate biofilm-producing S. maltophilia strains and aid in establishing appropriate antibiotic therapy.

Aztreonam plus ceftazidime-avibactam as treatment of NDM-1-producing Klebsiella pneumoniae bacteraemia in a neutropenic patient: Last resort therapy?

OBJECTIVES: We report the successful treatment of a bloodstream infection caused by Klebsiella pneumoniae harbouring NDM-1 using aztreonam-ceftazidime-avibactam in a neutropenic patient in whom colistin and meropenem therapy had previously failed. METHODS: A clinical isolate was evaluated to determine the presence of NDM, TEM, SHV, CTX, and CMY, and the killing kinetics of aztreonam (ATM; 4 µg/mL), aztreonam-avibactam (ATM-AVI; 4/4 µg/mL), and colistin (2 and 4 µg/mL) were tested. RESULTS: ATM-AVI showed in vitro activity against the Klebsiella pneumoniae harbouring NDM-1, whereas colistin allowed re-growth. CONCLUSIONS: This report supports reconsideration of use of colistin for treatment of infections caused by K. pneumoniae harbouring NDM. CZA/ATM use should be kept in mind as a treatment option, perhaps earlier than colistin.

The successful containment of a hospital outbreak caused by NDM-1-producing Klebsiella pneumoniae ST307 using active surveillance.

The worldwide dissemination of high-risk carbapenemase-producing Klebsiella pneumoniae clones has become a major threat to healthcare facilities. This study describes the successful containment of a hospital outbreak caused by NDM-1-producing K. pneumoniae Sequence Type (ST) 307 using active surveillance. The outbreak began when a patient was transferred from a local hospital. After 48 hours in our hospital, a tracheal aspirate was positive for a meropenem resistant and carbapenemase-producing K. pneumoniae. All patients in the medical intensive care unit (ICU) and the neurology wards were subject to contact precautions. The hospital surfaces and devices, healthcare workers, and patients from these wards were screened by cultures. Fecal swabs were placed into broth and PCR for blaKPC, blaOXA-48, blaIMP, blaVIM, and blaNDM, which were performed directly from the broth after 12 hours. PCRs were also performed on DNA extracted from carbapenemase-producing species from subcultured broths. Five and nine days later, two more patients' rectal swabs tested positive. Molecular assays identified K. pneumoniae blaNDM-1 onto a 130-kb conjugative plasmid (IncY, IncFIIs, and IncFIIY), ST307. After the three patients were discharged, monitoring continued, and after three weeks with negative results, rectal swabbing ended. In conclusion, it was possible to contain a hospital outbreak caused by NDM-1-producing K. pneumoniae ST307 through epidemiological and microbiological surveillance. With the methodology used, the detection of NDM-type genes in fecal samples was obtained in approximately 15 hours after obtaining the fecal sample.

Mumps outbreak with high complication rates among residents in a university teaching hospital.

According to the US Advisory Committee on Immunization Practices recommendations, only health care personnel (HCP) with adequate evidence of immunity should be exposed to patients with a suspected diagnosis of mumps. Here we report a hospital-outbreak scenario among medical residents with no previous vaccination record against mumps who had a high rate of complications. We also describe the importance and impact of full and proper vaccination, as well as isolation, of HCP in stopping the outbreak and, finally, review opportunities for improving the safety of HCP.