The polymicrobial infection affects the infection recurrence rate (not failure) in treating femoral and tibial bone defects with the Masquelet technique-a comparative retrospective analysis of 54 patients with mono- and polymicrobial infections.

INTRODUCTION: This study evaluated whether polymicrobial infection affects reoperation rates due to infection recurrence and treatment failure with the Masquelet technique in infected posttraumatic segmental bone defects of the femur and tibia. METHODS:  We retrospectively analyzed patients treated between 2012 and 2021 in two trauma referral centers. We evaluated demographic data, injury, treatment, infection recurrence, failures, and bone healing rates according to whether the infection was mono- or polymicrobial. After uni-bivariate analysis between patients with polymicrobial and monomicrobial infection, we identified the variables associated with infection recurrence and failure through multivariate analysis. RESULTS:  We analyzed 54 patients, 30 (55.55%) with tibial and 24 (44.44%) femoral segmental bone defects, with a mean follow-up of 41.7 ± 15.0 months. Forty-four (81.48%) presented monomicrobial, and 10 (18.51%) polymicrobial infections. Comparatively, the need for soft tissue reconstruction and the infection recurrence rate was significantly higher in patients with polymicrobial infections. There was no significant difference in the failure rate (20 vs. 6.81% p = 0.23). Multivariable logistic regression analysis identified the polymicrobial infection as the only independent variable associated with infection recurrence (Odds Ratio = 11.07; p = 0.0017). CONCLUSION:  Our analysis suggests that polymicrobial infection is associated with a higher risk of infection recurrence in treating the femur and tibia segmental bone defects with the Masquelet technique. This information can help surgeons to inform patients about this and give them a realistic expectation of the outcome and the possibility of reoperation.

Staphylococcus aureus in Polymicrobial Skinand Soft Tissue Infections: Impact of Inter-Species Interactionsin Disease Outcome.

Polymicrobial biofilms provide a complex environment where co-infecting microorganisms can behave antagonistically, additively, or synergistically to alter the disease outcome compared to monomicrobial infections. Staphylococcus aureus skin and soft tissue infections (Sa-SSTIs) are frequently reported in healthcare and community settings, and they can also involve other bacterial and fungal microorganisms. This polymicrobial aetiology is usually found in chronic wounds, such as diabetic foot ulcers, pressure ulcers, and burn wounds, where the establishment of multi-species biofilms in chronic wounds has been extensively described. This review article explores the recent updates on the microorganisms commonly found together with S. aureus in SSTIs, such as Pseudomonas aeruginosa, Escherichia coli, Enterococcus spp., Acinetobacter baumannii, and Candida albicans, among others. The molecular mechanisms behind these polymicrobial interactions in the context of infected wounds and their impact on pathogenesis and antimicrobial susceptibility are also revised.

Interspecies interactions in mixed-species biofilms formed by Enterococcus faecalis and gram-negative bacteria isolated from polymicrobial diabetic foot ulcers.

Diabetic foot ulcers (DFU) are exacerbated by bacterial colonisation. Here, a high prevalence of Enterococcus faecalis was observed in DFU patients from an Argentinean hospital. E. faecalis was frequently co-isolated with Escherichia coli, Morganella morganii, and Pseudomonas aeruginosa. The effect of interspecies interactions on bacterial growth was investigated in mixed-species macrocolony biofilms developed in Lubbock-Glc-agar. Similar cell counts were found for E. faecalis and M. morganii growing in mixed and single-species biofilms. An E. faecalis strain showed 1 Log higher cell counts in mixed biofilms with E. coli. Remarkably, E. faecalis strains showed 2 to 4 Log higher cell counts in mixed biofilms with P. aeruginosa. This effect was not observed in planktonic growth or biofilms developed in tryptic soy agar. The present findings reveal bacterial interactions that benefit E. faecalis in mixed-species biofilms, mainly with P. aeruginosa, in a medium that partially mimics the nutrients found in DFU.

Caspofungin Inhibits Mixed Biofilms of Candida albicans and Methicillin-Resistant Staphylococcus aureus and Displays Effectiveness in Coinfected Galleria mellonella Larvae.

Candida albicans and Staphylococcus aureus are pathogens commonly isolated from bloodstream infections worldwide. While coinfection by both pathogens is associated with mixed biofilms and more severe clinical manifestations, due to the combined expression of virulence and resistance factors, effective treatments remain a challenge. In this study, we evaluated the activity of echinocandins, especially caspofungin, against mixed biofilms of C. albicans and methicillin-resistant (MRSA) or methicillin-susceptible S. aureus (MSSA) and their effectiveness in vivo using the Galleria mellonella coinfection model. Although caspofungin (CAS) and micafungin (MFG) inhibited the mixed biofilm formation, with CAS exhibiting inhibitory activity at lower concentrations, only CAS was active against preformed mixed biofilms. CAS significantly decreased the total biomass of mixed biofilms at concentrations of ≥2 µg/ml, whereas the microbial viability was reduced at high concentrations (32 to 128 µg/ml), leading to fungus and bacterium cell wall disruption and fungal cell enlargement. Notably, CAS (20 or 50 mg/kg of body weight) treatment led to an increased survival and improved outcomes of G. mellonella larvae coinfected with C. albicans and MRSA, since a significant reduction of fungal and bacterial burden in larval tissues was achieved with induction of granuloma formation. Our results reveal that CAS can be a therapeutic option for the treatment of mixed infections caused by C. albicans and S. aureus, supporting additional investigation. IMPORTANCE Infections by microorganisms resistant to antimicrobials is a major challenge that leads to high morbidity and mortality rates and increased time and cost with hospitalization. It was estimated that 27 to 56% of bloodstream infections by C. albicans are polymicrobial, with S. aureus being one of the microorganisms commonly coisolated worldwide. About 80% of infections are associated with biofilms by single or mixed species that can be formed on invasive medical devices, e.g., catheter, and are considered a dissemination source. The increased resistance to antimicrobials in bacterial and fungal cells when they are in biofilms is the most medically relevant behavior that frequently results in therapeutic failure. Although there are several studies evaluating treatments for polymicrobial infections associated or not with biofilms, there is still no consensus on an effective antimicrobial therapy to combat the coinfection by bacteria and fungi.

Fungal diseases: Oral dysbiosis in susceptible hosts.

The oral cavity is colonized by a large number of microorganisms that are referred to collectively as the oral microbiota. These indigenous microorganisms have evolved in symbiotic relationships with the oral mucosal immune system and are involved in maintaining homeostasis in the oral cavity. Although Candida species are commonly found in the healthy oral cavity without causing infection, these fungi can become pathogenic. Recents advances indicate that the development of oral candidiasis is driven both by Candida albicans overgrowth in a dysbiotic microbiome and by disturbances in the host's immune system. Perturbation of the oral microbiota triggered by host-extrinsic (ie, medications), host-intrinsic (ie, host genetics), and microbiome-intrinsic (ie, microbial interactions) factors may increase the risk of oral candidiasis. In this review, we provide an overview of the oral mycobiome, with a particular focus on the interactions of Candida albicans with some of the most common oral bacteria and the oral mucosal immune system. Also, we present a summary of our current knowledge of the host-intrinsic and host-extrinsic factors that can predispose to oral candidiasis.

An Unexpected Cause of Sepsis: Keep Pursuing the Source of Infection.

An 86-year-old man was found with altered mental status, fever and aphasia. His physical exam revealed nuchal rigidity but no other meningeal signs. Because the patient's mental status was declining, he was intubated and placed in mechanical ventilation. His head CT scan was unremarkable, without evidence of mass effect. A lumbar puncture yielded cerebrospinal fluid that was remarkable for the presence of gram-positive cocci in pairs. His blood cultures showed gram-negative bacilli. Given the presence of these organisms, a polymicrobial infection was suspected. An abdomino pelvic CT scan showed a multi-septated abscess within the right hepatic lobe. CT-guided percutaneous drainage was performed and a specimen for culture obtained, which grew Klebsiella pneumoniae. After receiving intravenous antibiotics and supportive care, the patient showed clinical improvement. In this patient, there was a central nervous system infection secondary to bacteremia in the setting of an intrabdominal infection. The inquiring clinician should take note that whenever a polymicrobial infection is evidenced, more than one site of infection should be considered in the differential diagnosis.

Fascitis necrosante abdominal en puérpera de once días. A propósito de un caso / Abdominal necrotizing fasciitis in a patient of eleven-days pospartum. A case report

Resumen ANTECEDENTES: La fascitis necrosante es una infección progresiva poco común, con elevada mortalidad, que puede afectar cualquier parte del cuerpo. En la mayoría de los casos se origina por una infección polimicrobiana, con subsecuente afectación de la fascia superficial, tejido y grasa subcutáneos, nervios, arterias, venas y la fascia profunda. CASO CLÍNICO: Paciente de 28 años, obesa, infectada con VIH, que ingresó al servicio de Obstetricia durante el puerperio, con temperatura de 39 °C, escalofríos y dolor abdominal. En la exploración física se observó una lesión negra-azulada, de bordes definidos, de aproximadamente 40 x 20 cm en el área abdominal, alrededor de la herida quirúrgica, con ampollas y olor fétido. Los estudios de laboratorio reportaron hemoglobina 10 g/L, proteína C reactiva 413 y creatinina 110 mg/dL. Se obtuvo una muestra de las ampollas para cultivo. Al día siguiente se repitieron los exámenes de laboratorio y se encontró hemoglobina 8.5 g/L, proteína C reactiva 516 y creatinina 215 mg/dL; el cultivo resultó positivo para Pseudomonas aeruginosa y Staphylococcus aureus. Se prescribió tratamiento endovenoso con antibióticos y la lesión se intervino quirúrgicamente con debridamiento. La evolución de la paciente fue satisfactoria y no reportó secuelas. CONCLUSIONES: El diagnóstico oportuno de la fascitis necrosante permite su tratamiento temprano y la supervivencia del paciente.

Abstract BACKGROUND: Necrotizing fasciitis is an uncommon progressive infection, with high lethality that can affect any part of the body, caused mostly by a polymicrobial infection affecting the superficial fascia, subcutaneous tissue, subcutaneous fat with nerves, arteries, veins and deep fascia. CLINICAL CASE: A 28-year-old woman with a history of obesity and HIV, admitted to the Obstetrics Service with fever (39° C), chills and abdominal pain. A black-bluish lesion was observed, with defined edges of approximately 40 x 20 cm in the abdominal area, around the surgical wound, with blisters and great stench. Hematological study was carried out Hb: 10 g/L, C-reactive protein: 413, and Creatinine: 110 mg/dL. Culture sample of the ampoules is taken. The next day the complementary ones are repeated and Hb is observed: 8.5 g/L, C-reactive protein: 516, and Creatinine: 215 mg/dL; the result of the culture positive for Pseudomonas aeruginosa y Staphylococcus aureus. Endovenous treatment with antibiotics and surgical treatment was used. We observed satisfactory evolution of the patient without sequelae. CONCLUSIONS: The opportune diagnosis of this pathology allows an early action, with the consequent survival of the patients.

Outcomes and Risk Factors for Polymicrobial Posttraumatic Osteomyelitis.

Background: We hypothesized that polymicrobial posttraumatic osteomyelitis (PTO) may be associated with worse outcomes when compared to monomicrobial PTO. We therefore attempted to show the outcomes and predisposing factors associated with polymicrobial PTO. Methods: A single-center case-control study was carried out from 2007 to 2012. The outcome variables analyzed were: the need for additional surgical and antibiotic treatments, rates of amputation, and mortality associated with the infection. Univariate and multivariable analyses using multiple logistic regression were performed to identify risk factors associated with polymicrobial PTO, and p < 0.05 was considered significant. Results: Among the 193 patients identified, polymicrobial PTO was diagnosed in 37.8%, and was significantly associated with supplementary surgical debridement (56.1% vs. 31%; p < 0.01), a higher consumption of antibiotics, and more amputations (6.5% vs 1.3%; p < 0.01). Factors associated with polymicrobial PTO in the multivariable analysis were older age (odds ratio [OR] = 1.02, 95% confidence interval [CI] = 1.01 to 1.03, p = 0.04), working in agriculture (OR = 2.86, 95% CI = 1.05 to 7.79, p = 0.04), open fracture Gustilo type III (OR = 2.38, 95% CI = 1.02 to 5.56, p = 0.04), need for blood transfusion (OR = 2.15, 95% CI = 1.07 to 4.32, p = 0.03), and need for supplementary debridement (OR = 2.58, 95% CI = 1.29 to 5.16, p = 0.01). Conclusions: PTO is polymicrobial in more than one-third of patients, associated with extra surgical and clinical treatment, and worse outcomes including higher rates of amputation.

Microbial analysis of root canal and periradicular lesion associated to teeth with endodontic failure.

The quantification of ten microorganisms at the root ends and in the surrounding periradicular lesions was performed. Thirty 3 mm samples root ends and 30 samples of the surrounding chronic periapical infection were collected during apical microsurgery. Samples were triturated, and the bacterial DNA was obtained. The bacterial quantification was performed by using the SYBR Green system. At least one microorganism was detected in all patients. In both the root end and periapical samples, Fusobacterium nucleatum (71.6%), Dialister pneumosintes (58.3%) and Tannerella forsythia (48.3%) were the most prevalent species. Dialister pneumosintes showed statistically significant values in the root end, and F. nucleatum was also significant in the apical periodontitis samples. A statistically significant association between T. forsythia and Porphyromonas gingivalis in the root ends was observed. Bacterial associations from 2 to 7 species were observed in most samples. Extra-radicular and/or intra-radicular infections were present in all teeth with failed endodontic treatment, and showed polymicrobial infection in most cases, with a predominance of F. nucleatum, D. pneumosintes and T. forsythia. When present, Enterococcus faecalis was never found to be the most prevalent species. The presence of a microbial diversity in post-treatment apical periodontitis confirms the polymicrobial and synergistic characteristic of this process. Our results show that the bacterial array associated with the 3 mm root ends and periradicular lesions in post-treatment apical periodontitis are complex and with a high inter-individual variability. These results might be useful to delineate treatment strategies for microbial elimination in apical periodontitis. Further studies are necessary to elucidate the role of these microorganisms in endodontic treatment failures.

A case report of a multi-drug resistant bacterial infection in a diabetic patient treated in northeast Brazil.

Diabetes mellitus is one of the most critical health conditions around the world, not only in terms of the number of affected people, disability, and premature mortality, but also in regards to the health care costs involved in controlling and treating its complications. Among the most constant ailments the diabetic patient suffers is the diabetic foot, defined as any infection, ulceration, and/or necrosis of deep tissues associated with neurological abnormalities and various degrees of peripheral vascular disease of the lower limbs. Diabetic foot ulcerations have become a major and increasing public health concern and its associated morbidities, impairment of the patients' quality of life, and the implied costs for management have attracted the attention of numerous health care providers. In this case report, the authors review a unique presentation of a polymicrobial infection of a multi-drug resistant character species formed by oxacillin-resistant Staphylococcus aureus, Acinetobacter baumannii and Acinetobacter lwoffii.

Surgical procedures to an experimental polymicrobial sepsis: cecal ligation and puncture

Sepsis is still a leading cause of death worldwide and the mechanism of shock remains to be completely understood. Several studies have aimed to evaluate the effects of several drugs and procedures in sepsis, and the most common models of this study are to challenge mice with LPS or to simulate a polymicrobial infection using a surgical procedure. Such procedure consists in exposure of the cecum by a midline laparotomy, ligature of ileocecal junction and perforation with a needle, squeezing cecum contents to the peritoneum cavity. Beyond the variations allowed by this model, the thickness of the needle used and the number of perforations seem to be an important factor, displaying different levels of sepsis severity. In this study, we used two mice strains (C57BL/6 and BALB/c) to describe the procedures of cecal ligation and puncture (CLP), comparing the survival rates of mice subjected to three different thicknesses of perforation.

Surgical procedures to an experimental polymicrobial sepsis: Cecal Ligation and Puncture

Sepsis is still a leading cause of death worldwide and the mechanism of shock remains to be completely understood. Several studies have aimed to evaluate the effects of several drugs and procedures in sepsis, and the most common models of this study are to challenge mice with LPS or to simulate a polymicrobial infection using a surgical procedure. Such procedure consists in exposure of the cecum by a midline laparotomy, ligature of ileocecal junction and perforation with a needle, squeezing cecum contents to the peritoneum cavity. Beyond the variations allowed by this model, the thickness of the needle used and the number of perforations seem to be an important factor, displaying different levels of sepsis severity. In this study, we used two mice strains (C57BL/6 and BALB/c) to describe the procedures of cecal ligation and puncture (CLP), comparing the survival rates of mice subjected to three different thicknesses of perforation.