Introduction: Modern herniology relies heavily on synthetic mesh prostheses, which have markedly reduced recurrence rates and improved outcomes. However, the use of tension-free repair in infected or highly contaminated fields remains insufficiently studied. Biologic implants based on the extracellular matrix (ECM) may attenuate the inflammatory response and reduce the risk of infection. This study evaluates the behavior of different implant types under experimental bacterial contamination. Materials and methods: Three implants were investigated: an extracellular bovine-derived peritoneum matrix, preserved dura mater (DM), and the composite mesh prosthesis UltraPro. The study was conducted on 78 rats. After the creation of a standardized anterior abdominal wall defect, the defect was repaired using one of the studied implants and subsequently inoculated with MRSA or E. coli. Animals were observed for 10 and 20 days. Microbiological, immunological (circulating immune complexes), hematological, and macroscopic parameters were evaluated. Results: MRSA contamination induced a pronounced local inflammatory response, including abscess formation on day 10, whereas E. coli was rapidly cleared from the implantation zone. No statistically significant differences in MRSA persistence or semi-quantitative titers were observed between ECM, UltraPro, and DM. Systemically, CIC patterns and hematological changes were similar between ECM and UltraPro, while DM—particularly under MRSA contamination—was associated with a more pronounced inflammatory response. Conclusions: Under conditions of experimental bacterial contamination, the extracellular bovine-derived peritoneum matrix demonstrated local and systemic inflammatory profiles comparable to those of the synthetic UltraPro mesh and more favorable than those of preserved dura mater. All implants elicited a controlled inflammatory reaction without evidence of systemic septic complications. These findings support further research, including clinical trials, on the use of extracellular bovine-derived peritoneum matrix for reconstructive surgery of anterior abdominal wall defects in contaminated and potentially contaminated fields.

Introduction.Infectious complications remain one of the key factors limiting the use of synthetic endoprostheses in abdominal wall reconstruction. Methicillin-resistant Staphylococcus aureus (MRSA) exhibits strong adherence to implant surfaces and pronounced biofilm formation, which enhances the inflammatory response and delays material integration. Biologic matrices are considered potentially more favorable in contaminated surgical fields; however, data on tissue response to xenoperitoneum-derived extracellular matrix (ECM) under MRSA contamination remain limited. Objective. To perform a comparative histological and morphometric assessment of inflammatory reaction, neovascularization, and tissue revitalization around ECM, UltraPro mesh, and preserved dura mater (DM) in an experimental MRSA contamination model. Materials and methods. The study included 42 rats, of which 36 were assigned to MRSA-contaminated groups (ECM, UltraPro, DM; postoperative days 10 and 20; n=6 per subgroup) and 6 to the control group. Implants measuring 1×1 cm were fixed into a standardized aponeurotic defect, followed by application of 0.5 mL of an MRSA suspension (10⁹ CFU). On postoperative days 10 and 20, tissue samples were harvested for histological evaluation and morphometric analysis of cellular infiltrate, abscesses, necrosis, inflammatory depth, angiogenesis, and revitalization. Statistical analysis was performed using Kruskal–Wallis and Mann–Whitney tests. Results.During the early postoperative period (day 10), the most pronounced granulocytic inflammatory response was observed in the implantation zones of preserved dura mater (DM) and the UltraPro mesh, whereas implantation of the xenoperitoneum-derived extracellular matrix (ECM) was associated with a comparatively milder tissue reaction. By postoperative day 20, all groups demonstrated a general trend toward a reduction in granulocytic infiltration; however, only the ECM group exhibited a statistically significant enhancement of angiogenesis and an increase in the depth of tissue revitalization (p < 0.05). Implantation of UltraPro was characterized by elevated macrophage activity and a tendency toward microabscess formation, while the DM group showed a reduction in the frequency of abscesses and necrotic changes by the end of the observation period. Conclusion.Under MRSA-contaminated wound conditions, xenoperitoneum-derived ECM induces a less pronounced early inflammatory response, promotes active angiogenesis, and demonstrates the highest degree of revitalization compared with UltraPro and DM. These findings indicate potential advantages of ECM for abdominal wall reconstruction in settings of bacterial contamination. Введение. Инфекционные осложнения остаются одним из ключевых факторов, ограничивающих использование синтетических эндопротезов при реконструкции передней брюшной стенки. Метициллин-резистентный Staphylococcus aureus (MRSA) обладает высокой адгезивностью к имплантатам и выраженным биоплёнкообразованием, что усиливает воспалительную реакцию и замедляет интеграцию материалов. Биологические матриксы рассматриваются как потенциально более благоприятные в условиях инфицированного операционного поля; однако данные о реакции тканей на внеклеточный матрикс ксенобрюшины (ВКМ) при MRSA-контаминации ограничены. Цель исследования. Провести сравнительную гистологическую и морфометрическую оценку воспалительной реакции, неоваскуляризации и ревитализации тканей вокруг ВКМ, UltraPro и консервированной твёрдой мозговой оболочки (ТМО) при экспериментальной MRSA-контаминации. Материалы и методы. В исследование включены 42 крысы, из которых 36 распределены по группам MRSA-контаминации (ВКМ, UltraPro, ТМО; 10-е и 20-е сутки; n=6 в каждой подгруппе) и 6 — в контрольную группу. Имплантаты размера 1×1 см фиксировали в стандартный дефект апоневроза, после чего наносили 0,5 мл суспензии MRSA 10⁹ КОЕ. На 10-е и 20-е сутки проводили забор материала, гистологическое исследование и морфометрию клеточного состава, абсцессов, некрозов, глубины воспаления, ангиогенеза и ревитализации. Для статистического анализа применяли критерии Крускала–Уоллиса и Манна–Уитни. Результаты. В ранний послеоперационный период (10-е сутки) наиболее выраженные проявления гранулоцитарного воспаления регистрировались в зоне имплантации ТМО и сетчатого эндопротеза UltraPro, тогда как при использовании ВКМ отмечался более умеренный характер тканевой реакции. К 20-м суткам во всех группах наблюдалась тенденция к уменьшению гранулоцитарной...

Detection of Actinomyces odontolyticus as an etiologic agent of soft tissue infection is an extremely rare phenomenon, since this microorganism in most cases is part of the commensal microbiota of the oropharynx and gastrointestinal tract. This article presents a clinical case of the first and the only case of A. odontolyticus detection in a bacteriologic culture from a postoperative wound in the Republic of Kazakhstan. This work represents the first recorded clinical case of identification of A. odontolyticus as the causative agent of postoperative wound soft tissue infection in a patient who underwent surgery for acute phlegmonous appendicitis. odontolyticus as the causative agent of soft tissue infection of a postoperative wound in a patient who underwent surgery for acute phlegmonous appendicitis. The case was recorded in the surgical department of the clinic of Karaganda Medical University, Karaganda, Republic of Kazakhstan.