Microbial landscape in hospital patients with new coronavirus disease (COVID-19), antibiotic resistance comparison vs. Pre-covid stage: a prospective study

Background. The new coronavirus infection has manifested untypically compared to other acute respiratory agents, posing a major challenge to researchers worldwide. Despite low incidence of bacterial complications, microbial coinfection plays an important role in the onset and development of severe COVID-19 to hamper diagnosis, treatment and prognosis.Objectives. A study of microbial landscape in secondary complications of COVID-19 and prevailing microbial-agent antibiotic resistance dynamics in COVID-19 vs. patients with pre-COVID community-acquired pneumonia.Methods. We analysed 1,113 bacterial sputum cultures in COVID-19 patients from 21 hospital of Krasnodar Krai. The study sample comprised 524 strains isolated from COVID-19 patients in bacteriological assays. The comparison sample included 643 positive sputum strains isolated from community-acquired pneumonia patients developing disease in outcome of acute respiratory infection in 2015–2018. The microbial aetiology landscape and strain antibiotic resistance have been compared in COVID-19 vs. patients with community-acquired pneumonia.Results. Gram-negative bacteria predominated in COVID-19 cultures (58%), followed by Gram-positive bacteria (15%) and fungi (27%). Acinetobacter baumannii (35%) and Klebsiella pneumoniae (33%) were about equally represented in Gram-negative flora, Pseudomonas aeruginosa (19%) and other microorganisms were half as common. Streptococcus pneumonia and Staphylococcus aureus accounted for 48 and 15% Gram-positive strains, respectively. Sputum-isolated fungi were mainly identifi ed as Candida albicans (89%). The Streptoccocus pneumoniae detection rate dropped to 7% in 2020 relative of other flora, which is 10 times less vs. pre-COVID rates, whilst the fungal rate increased dramatically. Antibiotic resistance increased in most isolated microbial strains.Conclusion. A Gram-negative-dominated aetiology of lower respiratory tract lesions, as well as higher risk of fungal and other opportunistic coinfections should be taken into account in patient treatment for a complicated coronavirus infection. A higher antibiotic resistance is induced by active indication-ignorant use of antibiotics, including pre-hospital treatment. A suitable treatment regimen in COVID-19 should avoid undue antibiotic prescriptions in every patient.

Differentiated approach to pancreatic-enteroanastomosis in pancreaticoduodenal resection: a clinical experimental controlled trial

Background. Despite decreasing mortality in pancreaticoduodenal resection, the incidence of postoperative complications in such patients remains high. The choice and formation of “reliable” pancreatic-enteroanastomosis remain relevant.Objectives. The improvement of immediate surgery outcomes in pancreaticoduodenal resection via development of a differentiated algorithm for pancreatic-enteroanastomosis formation.Methods. A prospective non-randomised controlled trial enrolled 90 patients with a pancreaticoduodenal resection surgery. The patients were divided in three cohorts, A (n = 30), B (n = 30) and control C (n = 30). Pancreatic shear wave ultrasound elastography was conducted pre-surgery in main cohorts A and B. Average parenchymal stiffness and intraoperative data decided between the two pancreatico-enteric anastomosis techniques, end-to-side or the original pancreatic-enteroanastomosis. Control cohort C had pancreatico-enteric anastomosis without taking into account the pancreas stiffness and macrocondition.Results. Class A postoperative pancreatic fistula was registered in 2 (6.7%) of 30 patients in cohort B; it was transient, asymptomatic, not requiring additional treatment or a longer postoperative period. No class B and C pancreatic-enteroanastomosis failures or stump pancreonecroses were observed in main cohorts A and B. Clinically significant class B and C postoperative pancreatic fistulae were registered in 5 (16.7%) of 30 patients in control cohort C (inter-cohort comparison statistically significant).Conclusion. The proposed differentiated approach to pancreatic-enteroanastomosis formation associates with a reliably low postoperative complication frequency and lack of clinically significant class B and C postoperative pancreatic fistulae.

Dermal extracellular matrix response to facetem implant: a randomised controlled experimental study

Background. A leading concept in modern regenerative medicine is the perspective of using own body resources to remodel organs and tissues via the formation of “living scaffold”. A pivotal role in the formation of dermal scaffold is played by fibroblasts that produce extracellular matrix (ECM).Aim. A study of the fibroblast activation mechanism mediating synthesis of the dermal ECM fibrillar component under the Facetem filler administration.Methods. The experimental trial was conducted in Wistar male rats (72 animals). Animals had 0.05 mL Facetem (Korea) injections subdermally. The filler is a calcium-containing product featuring gradual degradation delivered through structural microspheric properties of the Lattice-pore technology. Biological material was sampled at weeks 1 and 2 of months 1, 2, 3 and 5. Tissues were paraffin-embedded in standard histological assays and stained with Mallory’s trichrome, Picrosirius red in polarisation microscopy and immunohistochemistry with collagen types I, III and elastin antibodies (Abcam).Results. Collagen distribution in dermis and the filling zone suggests that collagen production occurs by week 2 of the Facetem filler placement followed by an increase in synthesised matrix volume to 4.39 ± 0.7 for collagen type I and 3.9 ± 0.2 for collagen type III (p < 0.05). The synthetic activity of fi broblasts reduces by month 3, albeit with collagen production remaining above control even by the end of month 5. Elastin synthesis also initiates by week 2 of the filler injection in dermis and grows by month 3.Conclusion. The presence of Facetem filler triggers a foreign body inflammatory response in dermis. This multifactorial process initiates with protein adsorption proceeding to dermal cell recruitment and modulation of fibroblasts and macrophages. Activation of these cell types induces neocollagenesis entailing the extracellular matrix synthesis and expansion in dermis.