Aerobic Microbiological Spectrum and Antibiotic Resistance in Children Operated for Anorectal Abscesses

(1) Background: Anorectal abscesses are a relatively rare pathology in childhood. Most often, male children under 1 year of age are affected. The importance of microbiological examination for the diagnosis and treatment of such patients remains debatable among surgeons, resulting in scarce data being available in the literature. We aimed to identify the aerobic microbiological spectrum and antibiotic resistance of isolates in children undergoing operation to treat anorectal abscesses. (2) Methods: We performed a case series of 102 children diagnosed and operated for anorectal abscesses over a period of 10 years (2010-2019). Purulent wound exudate was used for microbiological evaluation, which was subsequently cultured on 5% sheep-blood agar and eosin-methylene blue agar. For microbiological identification, conventional biochemical tests and semi-automated (API 20, bioMerieux, Marcy-l'Étoile, France) tests were used, as well as automated systems (Vitek-2 Compact, bioMerieux, France). Antimicrobial susceptibility testing was performed by the disk diffusion method of Bauer-Kirby and by determining the minimal inhibitory concentrations for glycopeptides. The results were interpreted according to the EUCAST standard for the corresponding year. (3) Results: Microbiological testing in children operated for anorectal abscesses mainly identified the gut commensals that normally reside in the rectal mucosa. Monocultures were found in just over half of the cases. Escherichia coli, Klebsiella pneumoniae complex, and Proteus mirabilis were the most frequently isolated. In addition, Staphylococcus aureus was found in 7% of patients. In Gram-negative bacteria, antibiotic resistance was most often observed in penicillins, cephalosporins, sulfonamides, and fluoroquinolones. (4) Conclusions: The increasing rates of antimicrobial resistance impose the need for the local monitoring of circulating commensal bacteria associated with anorectal abscesses in children to guide antibiotic therapy when indicated.

Yersinia enterocolitica Bacteremia Associated with a Ruptured Abdominal Aortic Aneurysm: A Case Report with Literature Review

Yersinia enterocolitica is a foodborne pathogen, mainly associated with disorders involving the gastrointestinal tract, including diarrhea, ileitis, and mesenteric lymphadenitis. Extraintestinal presentation is uncommon in healthy individuals, but bacteremia is reported in immunocompromised hosts. We present a 74-year-old male with Y. enterocolitica serogroup O:3 bacteremia who complicated to rupture of an abdominal aortic aneurysm. With the current case report, we aimed to emphasize the association of Y. enterocolitica bacteremia with abdominal aortic aneurysm rupture. Better surveillance is needed, not only to reduce morbidity and mortality but also to update current epidemiological data on the incidence of such associations.

The Serum ACE2, CTSL, AngII, and TNFα Levels after COVID-19 and mRNA Vaccines: The Molecular Basis

BACKGROUND

The SARS-CoV-2 virus as well as the COVID-19 mRNA vaccines cause an increased production of proinflammatory cytokines.

AIM

We investigated the relationship between ACE2, CTSL, AngII, TNFα and the serum levels of IL-6, IL-10, IL-33, IL-28A, CD40L, total IgM, IgG, IgA and absolute count of T- and B-lymphocytes in COVID-19 patients, vaccinees and healthy individuals.

METHODS

We measured the serum levels ACE2, AngII, CTSL, TNFα and humoral biomarkers (CD40L, IL-28A, IL-10, IL-33) by the ELISA method. Immunophenotyping of lymphocyte subpopulations was performed by flow cytometry. Total serum immunoglobulins were analyzed by the turbidimetry method.

RESULTS

The results established an increase in the total serum levels for ACE2, CTSL, AngII and TNFα by severely ill patients and vaccinated persons. The correlation analysis described a positive relationship between ACE2 and proinflammatory cytokines IL-33 (r = 0.539) and CD40L (r = 0.520), a positive relationship between AngII and CD40L (r = 0.504), as well as between AngII and IL-33 (r = 0.416), and a positive relationship between CTSL, total IgA (r = 0.437) and IL-28A (r = 0.592). Correlation analysis confirmed only two of the positive relationships between TNFα and IL-28A (r = 0.491) and CD40L (r = 0.458).

CONCLUSIONS

In summary, the findings presented in this study unveil a complex web of interactions within the immune system in response to SARS-CoV-2 infection and vaccination.

Cytokine profile in patients with acute bacterial meningitis

BACKGROUND

Bacterial meningitis is a life-threatening disease with high mortality and common long-term sequelae. The inflammatory response in the subarachnoid space, modulated by different cytokines, plays a major role in the pathogenesis of acute central nervous system infections. We aimed to examine correlations of interleukin (IL)-6, IL-8, IL-10, IL-12(p40), and tumor necrosis factor (TNF)-α levels with disease severity, complications, and outcome in patients with acute bacterial meningitis.

METHODS

The study involved 30 patients with bacterial meningitis/meningoencephalitis admitted to the University Hospital St. George, Plovdiv over a period of 4 years. Patients were selected based on clinical presentation and laboratory abnormalities, consistent with a neuroinfection. Enzyme-linked immunosorbent assay was used to measure the studied cytokines in both cerebrospinal fluid (CSF) and serum in parallel. For microbiological diagnosis multiplex, polymerase chain reaction, and CSF culture were used.

RESULTS

In patients with acute bacterial meningitis CSF levels of IL-6, IL-8, IL-10, and TNF-α are significantly increased than in serum. CSF TNF-α, CSF IL-8, and CSF IL-10 had a moderate negative correlation to CSF glucose. It was found that serum IL-8 is significantly elevated in patients who experienced neurological complications, have severe clinical course, and in deceased patients. CSF IL-10 is increased only in patients with severe acute bacterial meningitis.

CONCLUSION

Among patients with acute bacterial meningitis serum IL-8 could delineate these with increased risk of neurological complications, severe clinical course, and fatal outcome. Serum IL-8 and CSF IL-10 could be used as indicators of disease severity.

Streptococcus zooepidemicus Meningitis in an HIV-Positive Horse Breeder Patient: A Case Study and Literature Review

Streptococcus equi subsp. zooepidemicus is a rare etiologic agent of bacterial meningitis in humans. The disease is a zoonotic infection and is transmitted through close contact with domestic animals, mainly horses. Only 37 cases of Streptococcus zooepidemicus meningitis have been reported in the literature until July 2023. The aim of this study is to present a rare clinical case of S. zooepidemicus-related meningitis in a human immunodeficiency virus (HIV)-positive patient and analyze the literature. We present a 23-year-old horse breeder patient with advanced immunosuppression due to acquired immunodeficiency syndrome (AIDS) and S. zooepidemicus meningitis, admitted at the Clinic of Infectious Diseases, St. George University Hospital, Plovdiv. The course of meningitis was severe since the beginning, with significant cerebral edema, disturbances in consciousness, persistent fever, and the development of complications against the background of AIDS-related conditions. S. zooepidemicus was microbiologically detected from cerebrospinal fluid culture. After prolonged treatment and a long hospital stay, the patient's condition improved, and eventually he was discharged and recovered from the acute neuroinfection. Although extremely rare, S. zooepidemicus should be considered in patients with clinical and laboratory evidence of bacterial meningitis who have contact with animals, especially horses, other domestic animals, and their dairy products, as well as in immunocompromised patients. To the best of our knowledge, the current clinical case is the first report of S. zooepidemicus-related meningitis in a patient with HIV/AIDS.

Gordonia sputi as an Arising Causative Agent of Bacteremia in Immunocompromised Comorbid Dialysis Patients-A Case Report

Improvements in medical care have turned severe diseases into chronic conditions, but often their treatment and the use of medical devices are related to specific complications. Here, we present a clinical case of a long-term dialysis patient who was infected with a rare opportunistic infectious agent-Gordonia sputi. In recent years, the incidence of Gordonia spp. infections in immunocompromised patients with central venous catheters (CVC) has appeared to rise. The isolation and identification of Gordonia spp. are challenging and require modern techniques. In addition, the treatment is usually persistent and often results in CVC extraction, which is associated with further risk and costs for the patient. We also studied the alterations in the immune status of the patient caused by long-term renal replacement therapy and persistent hepatitis C virus infection. Antibiotic therapy and immunostimulation with Inosine pranobex lead to successful eradication of the infection without the need for CVC replacement.

Improvement and Validation of a Multi-Locus Variable Number of Tandem Repeats Analysis (MLVA8+) for Klebsiella pneumoniae, Klebsiella variicola, and Klebsiella quasipneumoniae

The genotyping of the multidrug-resistant Klebsiella pneumoniae species complex is essential to identify outbreaks and to track their source and spread. The aim of this study was to improve and extend the typeability, availability, cost and time efficiency of an existing multi-locus VNTR analysis (MLVA). A modified scheme (MLVA8+) was adopted and validated for strain-level differentiation of the three Klebsiella species involved in human pathology. A diverse set of 465 K. pneumoniae clinical isolates from 22 hospitals and 3 outpatient laboratories in Bulgaria were studied, where 315 were carbapenem-resistant. The MLVA8+ typeability was significantly improved and the typing data were validated against 158 isolates which were previously typed by WGS. The MLVA8+ results were highly concordant with the classic 7-locus MLST and the novel K. variicola MLST, but had greater congruency coefficients (adjusted Wallace). A major advantage was the differentiation of the hybrid cluster ST258 into its corresponding clades. Furthermore, the applicability of MLVA8+ was demonstrated by conducting a retrospective investigation of the intra-hospital spread of blaKPC-, blaNDM- and blaOXA-48-like producers. The MLVA8+ has improved utility and extended typing scope to K. variicola and K. quasipneumoniae, while its cost and time-to-result were reduced.

Current methods for microbiological diagnosis of acute central nervous system infections

The incidence of infections affecting the central nervous system has increased in recent years, making neuroinfections a current global health problem. The central nervous system is quite well protected from the external and internal environments, although it is susceptible to infection by a wide variety of pathogens. The etiological diversity further complicates the management of such infections because it is important to identify correctly the specific cause in order to choose the most appropriate antimicrobial therapy. Diagnosis is made not only based on clinical and epidemiological data but also on the results of clinical laboratory and microbiological examination of cerebrospinal fluid. This article aims to review current microbiological methods in the diagnosis of acute central nervous system infections and help healthcare providers to recognize their advantages and limitations in order to manage their patients appropriately.

Application of Fluorescent In Situ Hybridization for Quick Identification of Microorganisms from Positive Blood Cultures

AIM: The aim of this study was to evaluate the diagnostic potential of the fluorescent in situ hybridization (FISH) method for quick identification of microorganisms from positive blood cultures. MATERIALS AND METHODS: QuickFISH BC is a multicolor, qualitative nucleic acid hybridization assay using specific fluorescent-labeled probes for identification of Gram-positive bacteria (S. aureus, Coagulase-negative Staphylococcus spp. – CoNS, E. faecalis, and E. faecium); Gram-negative bacteria (E. coli, P. aeruginosa, and K. pneumoniaе), and fungi (C. albicans, C. tropicalis, and C. glabrata). This method applied to 72 positive blood cultures obtained from patients admitted at the University Hospital St. George – Plovdiv. A preliminary selection based on Gram staining was performed before the application of the FISH test. All microorganisms were subject to identification by routine biochemical tests, semi-automated and automated systems as well. Statistical data processing included descriptive statistics, nonparametric analysis for testing hypotheses by SPSS v. 22.0, and Microsoft Excel software. p < 0.05 was considered statistically significant. RESULTS: FISH detected microorganisms in 63 (87.5%) positive blood cultures, whereas no fluorescent signal was observed in 9 (12.5%). The latter was because not all the microorganisms we identified are included in the test spectrum, for example – Enterobacter spp. and Acinetobacter spp. By FISH, we found S. aureus in 10 (15.9%) cases, CoNS in 20 (31.6%), E. faecalis in 4 (6.4%), and E. faecium in 4 (6.4%). E. coli (n = 7; 11.1%) was the leading cause of bacteremia among Gram-negative bacteria, whereas C. albicans predominated (n = 4; 6.4%) among fungi. CONCLUSION: QuickFISH BC is a rapid and accurate screening method for the identification of some of the most frequent pathogens causing bacteremia. This enables the initiation of the early and adequate antimicrobial therapy. The lack of pathogen identification from positive blood cultures using this method implies the need to continue identification with other tests.

Elizabethkingia miricola Recovered from a Peritoneal Fluid Sample – A Clinical Case Report with Diagnostic Challenges

Background: Elizabethkingia spp. are Gram-negative, non-spore-forming bacteria that used to be rarely encountered but now they are of growing clinical significance. Furthermore, the diagnostic challenges to identification impede the complete elucidation of their epidemiology and association with human diseases. Case report: A 64-year-old man with liver cirrhosis due to alcohol abuse presented with fatigue, abdominal swelling, and bilateral scrotal edema. A peritoneal fluid sample was cultured and subject to a number of identification methods – API 20 NE (bioMerieux), automated Vitek-2 Compact (bioMerieux), MALDI-TOF MS (Vitek-MS, bioMerieux), and 16S rRNA gene sequencing. A final diagnosis of bacterascites was made on the basis of clinical, laboratory, and microbiological findings. Conclusion: To the best of our knowledge this is the first report of Elizabethkingia miricola being cultured from a peritoneal fluid sample in an immune-compromised host thus pointing to the emerging pathogenic role of the bacterium in patients with liver cirrhosis and ascites.  

Supralevator Abscess Complicated by Necrotic Fasciitis of Peritoneum, Genitalia, Anterior Abdominal Wall and Retroperitoneum

A supralevator anorectal abscess may lead to a rare clinical complication, such as perineal necrotizing fasciitis. A 57-year-old man was admitted on an emergency basis with evidence of a deep anorectal abscess of 5-day duration. The clinical presentation involved an unbounded purulent destructive inflammation spreading onto the adjacent areas, with the development of a septic condition. Following a short preparation, a radical surgical debridement of a subfascial purulent necrotic phlegmon of the pelvic space was performed. Since the lower part of the abdomen, retroperitoneum and scrotum were involved, 4 additional subsequent necrectomies were performed at 48-hour intervals. The aggressive radical operative treatment and the combined intensive therapy were the main contributors to the favorable outcome of the disease.

Combined testing of cerebrospinal fluid IL-12 (p40) and serum C-reactive protein as a possible discriminator of acute bacterial neuroinfections

INTRODUCTION

Central nervous system infections (CNS) are life-threatening diseases, with meningitis being the most common. Viral infections are usually self-limiting diseases but bacterial pathogens are associated with higher mortality rates and persistent neurological sequelae. We aimed to study the role of IL-6, IL-8, IL-10, IL-12(p40), TNF-α cytokines, classical cerebrospinal fluid (CSF) parameters, and serum C-reactive protein levels (CRP) for discriminating bacterial from viral central nervous system infections.

MATERIAL AND METHODS

This prospective study included 80 patients with clinical signs and abnormal cerebrospinal fluid laboratory findings typical for neuroinfection admitted to St. George University Hospital-Plovdiv. Routine methods such as direct microscopy, culturing and identification were used for microbiological analysis as well as latex-agglutination test and multiplex PCR. Cytokines' concentrations were measured by ELISA. CRP and CSF parameters were collected from the patients' medical records.

RESULTS

We observed the highest discriminatory power among cytokines for cerebrospinal IL-12(p40) (AUC = 0.925; p = 0.000). CSF protein levels were the best predictor for bacterial neuroinfection (AUC = 0.973; p = 0.000). The AUC for the serum CRP as a stand-alone biomarker was estimated to be 0.943. The discriminatory power can be increased up to 0.995 (p = 0.000) when combining cerebrospinal fluid IL-12(p40) and serum CRP, with an optimal cut-off value of 144 (Sensitivity 100%; Specificity 90.9%).

CONCLUSION

The combined testing of CSF IL-12(p40) and serum CRP is associated with the highest diagnostic accuracy.

Serum Procalcitonin Levels in Patients with Acute Central Nervous System Infections

BACKGROUND: Bacterial infections of the brain are associated with high mortality and neurological sequelae, whereas viral diseases are usually self-limiting. A fast and easy-to-perform biomarker is needed to improve management in these patients. AIM: Procalcitonin (PCT) testing has already been implemented in many laboratories for evaluating septic patients and it is an easily accessible biomarker, so we aimed to examine its role specifically in discriminating acute bacterial from viral infections of the central nervous system (CNS). MATERIALS AND METHODS: This prospective study included 80 patients with both clinical symptoms and laboratory findings suggesting acute CNS infection. The microbiological analysis included direct microscopy, culturing, latex-agglutination test, and multiplex polymerase chain reaction. PCT levels were measured by enzyme-linked fluorescent assay technology. RESULTS: Following the results of the microbiological analysis, the cases were divided into three groups – bacterial 26.3% (n = 21), viral 17.5% (n = 14), and unidentified neuroinfections – 56.2% (n = 45). A statistically significant difference in the median serum PCT was observed between the bacterial and viral neuroinfections (p = 0.004) as well as between bacterial and unidentified infections of the brain (p = 0.000). No significant difference was found (p = 1.000) when comparing viral and unidentified neuroinfection. The area under the receiver operating characteristic curve for serum PCT was 0.823 but could be increased to 0.929 when combining serum PCT and C-reactive protein (CRP). CONCLUSION: Serum PCT levels are significantly higher in patients with acute bacterial infections of the brain. As a stand-alone biomarker, its discriminatory power is not superior to the classical laboratory parameters in the cerebrospinal fluid and serum CRP. However, when combined with serum CRP, excellent discriminatory power is observed.

Structure Zone Investigation of Multiple Principle Element Alloy Thin Films as Optimization for Nanoindentation Measurements

Multiple principal element alloys, also often referred to as compositionally complex alloys or high entropy alloys, present extreme challenges to characterize. They show a vast, multidimensional composition space that merits detailed investigation and optimization to identify compositions and to map the composition ranges where useful properties are maintained. Combinatorial thin film material libraries are a cost-effective and efficient way to create directly comparable, controlled composition variations. Characterizing them comes with its own challenges, including the need for high-speed, automated measurements of dozens to hundreds or more compositions to be screened. By selecting an appropriate thin film morphology through predictable control of critical deposition parameters, representative measured values can be obtained with less scatter, i.e., requiring fewer measurement repetitions for each particular composition. In the present study, equiatomic CoCrFeNi was grown by magnetron sputtering in different locations in the structure zone diagram applied to multinary element alloys, followed by microstructural and morphological characterizations. Increasing the energy input to the deposition process by increased temperature and adding high-power impulse magnetron sputtering (HiPIMS) plasma generators led to denser, more homogeneous morphologies with smoother surfaces until recrystallization and grain boundary grooving began. Growth at 300 °C, even without the extra particle energy input of HiPIMS generators, led to consistently repeatable nanoindentation load–displacement curves and the resulting hardness and Young’s modulus values.