Coxiella burnetii Intratracheal Aerosol Infection Model in Mice, Guinea Pigs, and Nonhuman Primates Bacterial Infections

Coxiella burnetii, the etiological agent of Q fever, is a Gram-negative bacterium transmitted to humans by inhalation of contaminated aerosols. Acute Q fever is often self-limiting, presenting as a febrile illness that can result in atypical pneumonia. In some cases, Q fever becomes chronic, leading to endocarditis that can be life threatening. The formalin-inactivated whole-cell vaccine (WCV) confers long-term protection but has significant side effects when administered to presensitized individuals. Designing new vaccines against C. burnetii remains a challenge and requires the use of clinically relevant modes of transmission in appropriate animal models. We have developed a safe and reproducible C. burnetii aerosol challenge in three different animal models to evaluate the effects of pulmonary acquired infection. Using a MicroSprayer aerosolizer, BL/6 mice and Hartley guinea pigs were infected intratracheally with C. burnetii Nine Mile phase I (NMI) and demonstrated susceptibility as determined by measuring bacterial growth in the lungs and subsequent dissemination to the spleen. Histological analysis of lung tissue showed significant pathology associated with disease, which was more severe in guinea pigs. Infection using large-particle aerosol (LPA) delivery was further confirmed in nonhuman primates, which developed fever and pneumonia. We also demonstrate that vaccinating mice and guinea pigs with WCV prior to LPA challenge is capable of eliciting protective immunity th...
Source: Infection and Immunity - Category: Infectious Diseases Authors: Tags: Bacterial Infections Source Type: research

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Conclusions: As postoperative mortality in case of COVID pneumonia is not negligible, meticulous rules (precise triage, safe hospital path, high level of protection for health-care teams, prompt diagnosis of suspicious symptoms) should be strictly followed in patients undergoing CS during COVID pandemic. The role of therapies alternative to CS should be further assessed.
Source: Annals of Surgery - Category: Surgery Tags: COVID PAPERS Source Type: research
Staphylococcus aureus, one of the most important human pathogens, is the causative agent of several infectious diseases including sepsis, pneumonia, osteomyelitis, endocarditis and soft tissue infections. This pathogenicity is due to a multitude of virulence factors including several cell wall-anchored proteins (CWA). CWA proteins have modular structures with distinct domains binding different ligands. The majority of S. aureus strains express two CWA fibronectin (Fn)-binding adhesins FnBPA and FnBPB (Fn-binding proteins A and B), which are encoded by closely related genes. The N-terminus of FnBPA and FnBPB comprises an A ...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Abstract BACKGROUND: Patients with chronic renal failure (CRF) on hemodialysis are at increased risk for developing infective endocarditis (IE). However, outcomes of surgical treatment for IE in these patients have not been well studied. METHODS: Between 1997 to 2017, 539 patients underwent surgery for IE. Of these patients, 125 were on hemodialysis for end-stage renal disease (ESRD) and 414 had no history of CRF. Primary endpoints compared in this study were short- and long-term survival. RESULTS: Preoperatively, dialysis patients had higher incidences of diabetes (43% vs. 18%), hypertension (79% vs. 49...
Source: The Annals of Thoracic Surgery - Category: Cardiovascular & Thoracic Surgery Authors: Tags: Ann Thorac Surg Source Type: research
We report a jugular lymphnode abscess associated with facial percutaneous inoculation of B. pseudomallei. Hospital course was complicated by endocarditis, septic arthritis and pyelonephritis. Surgical drainage and intensive and eradicative phase of antibiotics successfully cured the disease.
Source: Journal of Maxillofacial and Oral Surgery - Category: ENT & OMF Source Type: research
Glucocorticoid-Induced Bacterial Endocarditis in COVID-19 Pneumonia - Something to Be Concerned About? Circ J. 2020 Aug 07;: Authors: Regazzoni V, Loffi M, Garini A, Danzi GB PMID: 32779609 [PubMed - as supplied by publisher]
Source: Circulation Journal - Category: Cardiology Authors: Tags: Circ J Source Type: research
Abstract Staphylococcus aureus is a pathogen that causes critical diseases, such as pneumonia, endocarditis, and bacteremia, upon gaining access to the bloodstream of the host. Because host innate immunity alone cannot fight against this rapidly expanding pathogen, the use of antibiotic agents is necessary to clear out S. aureus. However, sub-populations of S. aureus fail to respond to the antibiotics resulting in ineffective clearance of the bacteria. One mechanism by which S. aureus does not respond to the antibiotics is by developing resistance through alterations in its genetic makeup, and genetic studies have...
Source: Archives of Pharmacal Research - Category: Drugs & Pharmacology Authors: Tags: Arch Pharm Res Source Type: research
In this study, we first report a case of a child with MRSA-caused osteomyelitis who was successfully cured by VCM at a concentration of 4.86 μg/mL. VCM's clinical daily dose of more than 4 g was of concern in light of recent evidence suggesting the increased risks of nephrotoxicity and red man syndrome when Cmin ⩾15 μg/mL and doses ⩾10 mg/kg in children. As far as we know, this is the first report on the lower dose of VCM in children with MRSA osteomyelitis. PMID: 32567423 [PubMed - in process]
Source: International Journal of Immunopathology and Pharmacology - Category: Allergy & Immunology Tags: Int J Immunopathol Pharmacol Source Type: research
AbstractStaphylococcus aureus is known as a common pathogen that colonizes 30% of healthy humans. Additionally, this bacterium can cause a number of serious infections, that is, endocarditis, bacteremia, pneumonia, wound, skin infections, and tissue abscesses. A variety of cellular and molecular pathways and targets are involved in response againstS. aureus. Among them, microRNAs (miRNAs) have crucial roles in response againstS. aureus. In this regard, it has been shown that these molecules exert their regulatory roles via modulating a wide range of events, such as inflammatory reactions, host innate, and adaptive immunity...
Source: IUBMB Life - Category: Research Authors: Tags: CRITICAL REVIEW Source Type: research
This study aimed to investigate whether MRSA carriage affects postoperative outcomes and safety of operation. METHODS: A total of 1,774,811 cardiac surgery patients 2009-2014 were identified from the NIS database. Among these, 5,798 (0.33%) were MRSA carriers. Propensity-score matching was used to determine the effect of MRSA colonization on outcomes. RESULTS: MRSA carriers did not differ in age or sex from non-carriers, but more often presented for urgent surgery (p=0.0006). Among matched pairs, there was no difference in mortality (p=0.76), stroke, SSI, pneumonia, renal failure, cardiac complications, respirato...
Source: The Annals of Thoracic Surgery - Category: Cardiovascular & Thoracic Surgery Authors: Tags: Ann Thorac Surg Source Type: research
Conclusion: The population frequency of endogenous endophthalmitis has not changed over 16 years despite the changing profile of pathogen and risk factors. Similar to previous studies in Asian and Western countries, visual and anatomical prognosis depends on initial visual acuity and isolated pathogen. Gram-negative and filamentous fungi culture predicted a worse visual outcome.
Source: RETINA - Category: Opthalmology Tags: Original Study Source Type: research
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