Microbiological Characteristics Research Articles

The Efficacy of Daily Local Antibiotic Lavage via an Epidural Suction-Irrigation Drainage Technique in Spondylodiscitis and Isolated Spinal Epidural Empyema: A 20-Year Experience of a Single Spine Center.

Various treatment modalities are available for local antibiotic therapy in spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE), but there is no evidence-based recommendation. Postoperative epidural suction-irrigation drainage (ESID) is thought to reduce bacterial load, which may prevent the development of relapse, wound healing, hematogenous spread, and systemic complications. We evaluated the efficacy of postoperative ESID over 20 years on disease progression and outcome in SD and ISEE. Detailed demographic, clinical, imaging, laboratory, and microbiological characteristics were examined in our cohorts of 208 SD and ISEE patients treated with and without ESID at a university spine center in Germany between 2002 and 2022. Between-group comparisons were performed to identify meaningful differences for the procedure. We included data from 208 patients (142 SD, 68.3% vs. 66 ISEE, 31.7%) of whom 146 were ESID patients (87 SD, 59.6% vs. 59 ISEE, 40.4%) and 62 were NON-ESID patients (55 SD, 88.7% vs. 7 ISEE, 11.3%). ESID patients with SD showed more frequent SSI (ESID: 22, 25.3% vs. NON-ESID: 3, 5.5%, p = 0.003), reoperations due to empyema persistence or instability (ESID: 37, 42.5% vs. NON-ESID: 12, 21.8%, p = 0.012), and a higher relapse rate (ESID: 21, 37.5% vs. NON-ESID: 6, 16.7%, p = 0.037) than NON-ESID patients with SD. The success rate in NON-ESID patients with SD was higher than in ESID patients with SD (ESID: 26, 29.9% vs. NON-ESID: 36, 65.6%, p < 0.001). Multivariate binary logistic regression analysis showed that ESID therapy (p < 0.001; OR: 0.201; 95% CI: 0.089-0.451) was a significant independent risk factor for treatment failure in patients with SD. Our retrospective cohort study with more than 20 years of experience in ESID technique shows a negative effect in patients with SD in terms of surgical site infections and relapse rate.

Perspective on receptor-associated immune response to Candida albicans single and mixed infections: implications for therapeutics in oropharyngeal candidiasis.

Oropharyngeal candidiasis (OPC), commonly known as 'thrush', is an oral infection that usually dismantles oral mucosal integrity and malfunctions local innate and adaptive immunities in compromised individuals. The major pathogen responsible for the occurrence and progression of OPC is the dimorphic opportunistic commensal Candida albicans. However, the incidence induced by non-albicans Candida (NAC) species including C. glabrata, C. tropicalis, C. dubliniensis, C. parapsilosis, C. krusei are increasing in company with several oral bacteria, such as Streptococcus mutans, Streptococcus gordonii, Staphylococcus epidermidis and Staphylococcus aureus. In this review, the microbiological and infection features of C. albicans and its co-contributors in the pathogenesis of OPC are outlined. Since the invasion and concomitant immune response lie firstly on the recognition of oral pathogens through diverse cellular surface receptors, we subsequently emphasize the roles of epidermal growth factor receptor (EGFR), ephrin-type receptor 2 (EphA2), human epidermal growth factor receptor 2 (HER2), aryl hydrocarbon receptor (AhR) located on oral epithelial cells to delineate the underlying mechanism by which host immune recognition to oral pathogens is mediated. Based on these observations, the therapeutic approaches to OPC comprising conventional and non-conventional antifungal agents, fungal vaccines, cytokine and antibody therapies, and antimicrobial peptide therapy are finally overviewed. In face of newly emerging life-threatening microbes (C. auris and SARS-CoV-2), risks (biofilm formation and interconnected translocation among diverse organs), and complicated clinical settings (HIV and oropharyngeal cancer), the research on OPC is still a challenging task.

Effect of the autochthonous starter culture on physicochemical, microbiological, and sensory characteristics of traditional colombian double-cream cheese: A kinetic approach

Double-cream cheese is a Colombian pasta-filata cheese made from fresh and acidified cow milk. Two kinds of cheese were compared: conventional (QTR) and autochthonous starter culture added (QCP). Double-cream cheeses with yield, moisture, fat, and protein of 10.98%, 48.52 g/100 g, 24.58 g/100 g, and 23.23 g/100 g were obtained, respectively. For both kinds of cheese, no significant differences during the storage period for pH (5.19), acidity (0.3 g/100 g), moisture (46.73 g/100 g), and total solids (53.47 g/100 g) were observed. The values of cohesiveness (0.33), gumminess (18.91 J), hardness (30.03 N), and chewiness (14.75 J) were higher for QCP during the storage time. General quality for QTR and QCP were 9.35 ± 0.87 and 9.25 ± 0.24, respectively. At the end of the storage period, QTR exhibited a higher count of total coliforms (7.20 ± 0.00 log CFU/g), while QCP showed a lower count (3.58 ± 0.98 log CFU/g). The specific growth rates of total coliforms in QTR and QCP were 0.0146 h−1 and 0.0068 h−1, respectively. QCP demonstrates an extended shelf life of 22 days more than QTR under optimal initial conditions (0.00 log CFU/g). The autochthonous starter culture can inhibit coliform growth, enabling the production of cheese with extended shelf life and similar sensory qualities to conventional cheese.

Microevolution of a Mycobacteroides abscessus subsp. bolletii strain in a clinical persistent infection.

Mycobacteroides abscessus complex (MAB), a fast-growing nontuberculous mycobacterium, is emerging as a significant infectious disease threat, due to both intrinsic and acquired resistance mechanisms to antibiotics and disinfectants and the need for extensive and multidrug regimens for treatment. Despite the prolonged regimens, outcomes are poor and persistence cases have been reported. Here, we describe clinical, microbiologic and genomic features of a M. abscessus subsp. bolletii (M. bolletii) strain consecutively isolated from a patient within an eight-year infection period. From April 2014 to September 2021, the National Reference Laboratory for Mycobacteria received eight strains isolated from a male patient. Species identification, molecular resistance profile and phenotypic drug susceptibility were determined. Five of these isolates were recovered for further in-depth genomic analysis. Genomic analysis confirmed the multidrug resistant pattern of the strain and also other genetic changes associated with adaptation to environment and defence mechanisms. We highlight the identification of new mutations in locus MAB_1881c and in locus MAB_4099c (mps1 gene), already described as associated with macrolides resistance and morphotype switching, respectively. Additionally, we also observed the emergence and fixation of a mutation in locus MAB_0364c that appeared at a frequency of 36% for the 2014 isolate, 57% for the 2015 isolate and 100% for the 2017 and 2021 isolates, clearly illustrating a fixation process underlying a microevolution of the MAB strain within the patient. Altogether these results suggest that the observed genetic alterations are a reflection of the bacterial population's continuous adaptation and survival to the host environment during infection, contributing to persistence and treatment failure.

Microbiology and Clinical Outcome of Bloodstream Infections in Patients After Hematopoietic Stem Cell Transplantation.

Patients after hematopoietic stem cell transplantation (HSCT) are often followed by bloodstream infections (BSIs). BSI is an important cause of non-relapse mortality (NRM) in HSCT patients. We conducted a retrospective cohort study of patients (aged >14 years) who underwent HSCT at our hospital from 2017 to 2021. Population characteristics, BSI microbiology, resistance to common antibiotics, and 30-day all-cause mortality were analyzed. Of 3054 patients, 169 (5.5%) had BSIs after HSCT. Male, not in complete remission at transplantation and longer duration of neutropenia were risk factors for the development of BSI after HSCT. These BSIs were Gram-negative bacterial (n=123, 69.49%), Gram-positive bacterial (n=27, 15.25%), fungal (n=11, 6.36%), and polymicrobial (n=16, 9.25%). Among the Gram-negative bacteria, the proportions of isolates resistant to ceftazidime, cefepime, and piperacillin-tazobactam were similar (72.93%, 74.80%, and 77.42%, respectively). The overall drug resistance rates of amikacin and imipenem were 16.13% and 43.90%, respectively. Staphylococcus isolates were methicillin-resistant. In Enterococcus isolates, the penicillin resistance rate was 84.62%. Eleven isolates of Candida tropicalis were resistant to fluconazole and were sensitive to amphotericin B and flucytosine. The 30-day all-cause mortality rate of the 169 patients with BSIs was 8.88%. The 30-day all-cause mortality of patients with Gram-negative bacterial BSIs was 7.32%, 25.00% for polymicrobial BSIs, and 36.36% for fungal BSIs. The 30-day all-cause mortality of patients with fungal BSIs was significantly higher than that of patients with Gram-negative (P=0.0023) and Gram-positive bacteria (P=0.0023). Fungal BSI and non-Hodgkin's lymphoma (NHL) were associated with higher 30-day mortality. Our study reveals the microbiological characteristics and 30-day all-cause mortality in patients with bloodstream infections after HSCT. Our data provides strong support for empirical antimicrobial therapy and infection prevention strategies for patients with BSIs after HSCT.

Characteristics of lactose-free/low-lactose fermented dairy products containing microorganisms that are part of the kefir grain consortium: Scoping review

Introduction: There are a significant number of scientific publications dedicated to the analysis of lactose-free and low-lactose fermented milk products, primarily in the context of studying specific microorganisms or starter cultures and their functioning under conditions of limited lactose content. Nevertheless, the synthesis of accumulated data has not been sufficiently highlighted, considering that a large part of the research was conducted over the past 10 years, and an intensive examination of this issue has only begun in the recent past.Purpose: To systematically and critically analyze scientific research that sheds light on the specifics of fermented milk products with a reduced lactose level, focusing on a comparative study of standard fermented milk products and their low-lactose or lactose-free modifications. Special attention is paid to fermented milk products containing microorganisms that are part of the kefir fungus consortium.Materials and Methods: Sources for the review were selected from the Scopus, ScienceDirect, RISC (Russian Index of Science Citation), and Google Scholar databases. Out of 208 publications relevant in terms of keywords, 34 were selected for analysis. The main criterion for selecting articles was a description in them of studies on the use of low-lactose or lactose-free milk as a medium for cultivating starter cultures. This review of the subject area is based on the PRISMA-ScR protocol.Results: Many scientific studies indicate that the prepared low-lactose or lactose-free fermented milk products exhibited similar or improved physicochemical and organoleptic characteristics compared to standard fermented milk products. In experiments aimed at evaluating microbiological characteristics, it was observed that the concentration of lactic acid bacteria in the analyzed products either matched, was lower, or was higher than in traditional fermented milk products. In some publications, scientists found that the final fermented milk product had deteriorated organoleptic and physicochemical parameters. However, all reviewed low-lactose or lactose-free fermented milk products met the standards and regulatory requirements of the countries in which the respective research was conducted.Conclusion: The development of low-lactose and lactose-free fermented milk products is a relevant direction in the food industry, considering their similarity to conventional products and adaptability for consumption by individuals with varying degrees of lactose intolerance. There are nuances related to the duration of the fermentation process, organoleptic characteristics, acidity level, syneresis, preservation, and growth dynamics of microorganisms. These features can be dictated by specific strains of microflora used in the starter and, most often, their influence remains minimal. The results obtained in this study may be useful for selecting starter cultures when designing various fermented milk products, including yogurt, fortified yogurt, kefir, ayran, ryazhenka, and acidophilus. For a deeper understanding of the interaction of the modified glucose-galactose medium with various strains and species of lactic acid bacteria, further experimental work is needed, considering that the activity of these bacteria directly determines the quality characteristics of the final fermented milk product.

Halal Fermented Functional Food in Indonesia: A Review

Nowadays, people prefer to consume foods with better nutrition to enjoy life more healthily. However, Muslims must also eat halal food following the Islamic way of life; eating nutritious food alone is insufficient. Indonesia, the largest Muslim population in the world, presents a market potential for halal food manufacturers and consumers worldwide. Several varieties of regional fermented foods were listed on the halal-positive food list and free from the requirement of halal certification, as per Indonesian Halal rules. The review of Indonesian fermented foods listed in the category of positive halal foods is the main topic of this essay. The procedures used to review the chosen themes include finding the literature in online sources, screening for topic inclusion, and evaluating, extracting, and discussing the accessible data found in the publications. The potential functional local fermented food varieties are included on the positive halal list: Tape (sticky rice and cassava), Dadih, and Tempeh. These fermented foods' microbiological and chemical characteristics were discussed. Therefore, the functional value of these fermented foods is rich in phytochemicals, anti-cancer (β-glucan), antioxidant compounds (isoflavones) and probiotic components (lactic acid bacteria and yeasts).

Infective endocarditis in octogenarians: a retrospective study in a single, high-volume surgical centre

Abstract Funding Acknowledgements Type of funding sources: None. Background Infective endocarditis (IE) is a severe disease associated with high morbidity and mortality. Little is known about the best management of elderly patients with IE. In these patients, surgery may be challenging. Our study aimed to describe IE’s features in octogenarians and to identify the independent predictors of mortality, focusing on the prognostic impact of disability. Methods We retrospectively analyzed 551 consecutive patients admitted to a single surgical centre with a definite diagnosis of non-device-related infective endocarditis; of these, 97 (17.6%) were older than 80 years. Results In patients under eighty, males were mostly involved with a sex ratio exceeding 2:1. This ratio was inverted in older people, where the female gender represented 53.6% of the total. Enterococci (29.8 vs 17.4%, p = 0.005) were significantly more frequent than in younger people. Comorbidities were more frequent in elderly patients; consequently, EUROSCORE II was higher (median ± IQR 16.4 ± 21.1 vs 5.0 ± 10.3, p = 0.001). In octogenarians, IE was more frequently left-sided (97.9 vs 89.8%, p = 0.011). Octogenarians were more often excluded from surgery despite indication (23.7 vs 8.1%, p = 0.001) and had higher three-year mortality (45.3 vs 30.6%, p = 0.005) than younger patients. In elderly patients, age did not independently predict mortality, while exclusion from surgery and a high grade of disability did. Conclusions Octogenarians with IE have specific clinical and microbiological characteristics. Older patients are more often excluded from surgery, and the overall prognosis is poor. Age per se should not be a reason to deny surgery, while disability predicts futility.

Development, quality and safety evaluation of a probiotic whey beverage

Background: This study was aimed at the development of a whey beverage enriched with a probiotic starter culture, prebiotics, vitamins, and minerals, and evaluation of microbiological, physico-chemical, and toxicological characteristics of the developed beverage.Methods: The beverage formulation was determined based on organoleptic analysis. The assessment of microbiological and physico-chemical parameters was carried out in accordance with regulatory standards. The safety assessment of the developed drink was carried out in vivo.Results:A beverage formulation based on whey enriched with probiotic bacteria Lactobacillus casei 1A, Lactobacillus paracasei 2A, Lactobacillus brevis 4 LB, prebiotic inulin, vitamins (A, C) and minerals (potassium iodide) was developed. The organoleptic, physico-chemical, and microbiological properties of the developed drink were determined. The quality of the beverage complied with food safety regulations, the viability of probiotic bacteria and the acidity of the beverage remained stable during storage. Acute score toxicity and allergenic properties in vivo did not reveal any physiological abnormalities and made it possible to classify the developed product as a low-hazard substance.Conclusion:The optimal composition of a probiotic whey beverage has been developed, which can be considered as a potential product for functional nutrition.Keywords: Whey beverage, Formulation, Probiotic, Functional, Safety Assessment, Toxicity, Allergenic properties, In vivo

Polyphasic characterization of a novel hot-spring cyanobacterium Thermocoleostomius sinensis gen et sp. nov. and genomic insights into its carbon concentration mechanism.

Thermophilic cyanobacteria play a crucial role as primary producers in hot spring ecosystems, yet their microbiological, taxonomic, and ecological characteristics are not extensively studied. This study aimed to characterize a novel strain of thermophilic cyanobacteria, PKUAC-SCTA174 (A174), using a combination of traditional polyphasic methods and modern genomic-based approaches. The study included 16S rRNA-based phylogeny, ITS secondary structure prediction, morphological and habitat analyses, as well as high-quality genome sequencing with corresponding phylogenomic analyses. The results of the 16S rRNA, 16S-23S ITS secondary structure, morphology, and habitat analyses supported the classification of the strain as a member of a novel genus within the family Oculatellaceae, closely related to Albertania and Trichotorquatus. Genomic analysis revealed the presence of a sophisticated carbon-concentrating mechanism (CCM) in the strain, involving two CO2 uptake systems NDH-I3, and NDH-I4, three types of bicarbonate transporters (BCT1, bicA, sbtA,) and two distinct putative carboxysomal carbonic anhydrases (ccaA1 and ccaA2). The expression of CCM genes was investigated with a CO2 shift experiment, indicating varying transcript abundance among different carbon uptake systems. Based on the comprehensive characterization, the strain was delineated as Thermocoleostomius sinensis, based on the botanical code. The study of the complete genome of strain A174 contributes valuable insights into the genetic characteristics of the genus Thermocoleostomius and related organisms and provides a systematic understanding of thermophilic cyanobacteria. The findings presented here offer valuable data that can be utilized for future research in taxogenomics, ecogenomics, and geogenomics.

Production of the probiotic dessert containing sprouted quinoa milk and evaluation of physicochemical and microbial properties during storage.

One of the challenges of the food industry is detecting the potential of novel non-dairy food matrices to deliver probiotic bacteria to humans as cholesterol-free products, suitable for people with lactose intolerance and sensitivity to dairy proteins. In this study, the possibility of adding sprouted quinoa milk (SQM) at 0%, 50%, and 100% levels in probiotic non-dairy dessert containing native Lactobacillus plantarum isolated from camel milk was investigated. Physicochemical, functional, microbiological, color, texture, and organoleptic characteristics of probiotic dessert samples were evaluated during 1, 7, and 14 days of storage at 4°C. According to the results, fat, protein, carbohydrates, and ash increased significantly during germination (p < .05). With boosting the SQM levels in the probiotic desserts, the number of soluble solids increased, and the syneresis decreased significantly (p < .05). The simultaneous increase in SQM levels and time caused an increase in acidity and decreased the moisture content of the samples. As the storage time increased, the intensity of the syneresis also decreased. The brightness index in all samples containing SQM was lower than in the control sample. During storage, the viable cell number of Lactobacillus plantarum in all samples decreased significantly. However, they were above the minimum required for FDA recommendation (6 log CFU g-1), varying from 4.6 × 108 CFU/mL to 4.3 × 107 CFU/mL for 50% SQM treatment. It was concluded that probiotic desserts containing SQM up to 50% could be properly presented in the market as gluten-free and functional food products.

Real-World Data Regarding Dalbavancin Use before and during the COVID-19 Pandemic-A Single-Center Retrospective Study.

Dalbavancin is a semisynthetic lipoglycopeptide, which possesses great potential for bactericidal activity similar to antimicrobials with the same mechanism of action, such as vancomycin and teicoplanin. Due to its very prolonged half-life, it can be used in a single or two-dose regimen to treat infections by Gram-positive microorganisms, even resistant ones, such as methicillin-resistant Staphylococcus aureus (MRSA). Currently, it is approved only for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). The aim of this study was to investigate the clinical and microbiological characteristics of patients to whom dalbavancin was administered at the University Hospital of Heraklion and evaluate its use in regard to the COVID-19 pandemic. In total, 146 patients were included in this retrospective cohort study evaluating the use of dalbavancin from the first time it was used in 2017 until the end of 2022. The median age was 68 years (range: 21-96 years), and 86 (59%) patients were male. The most common indications for dalbavancin use were osteoarticular infections in 43%, followed by ABSSSIs in 37%, and cardiovascular infections in 10%. Dalbavancin was used empirically in one out of three patients, most commonly with the indication of ABSSSIs, and most commonly in the post-COVID-19 era. The most frequently isolated pathogens were coagulase-negative staphylococci in 70%, S. aureus in 27%, Enterococcus spp. in 22%, and Streptococcus spp. in 8%, while one out of three infections were polymicrobial. In 12% of patients, the infection was not cured, but no patients died. For patients with ABSSSIs, endocarditis and vascular infections, and bacteremia, the cure rates were more than 90%, and in osteoarticular infections, the cure rate was 76%. Thus, dalbavancin has great potential for use in complicated and invasive infections that may require prolonged intravenous antimicrobial treatment. However, further studies are required to formally investigate its role in such infections.

Preparation and Characterization of Novel Chitosan Coatings to Reduce Changes in Quality Attributes and Physiochemical and Water Characteristics of Mongolian Cheese during Cold Storage.

The objective of this study was to evaluate the effect of O-carboxymethyl chitosan coating on microbiological, physiochemical, and water characteristics of Mongolian cheese during refrigerated storage. O-carboxymethyl chitosan coatings, particularly at 1.5%, improved cheese preservation by significantly inhibiting microbial growth, reducing changes in protein and non-protein nitrogen, and preserving pH and titratable acidity. For texture profile analysis (TPA), the hardness, gumminess, and chewiness in O-CMC treatments were significantly more stable than those in the control during storage. In addition, the relaxation component and image of nuclear magnetic resonance (NMR) were used to analyze the internal water mobility of the cheese during storage. Compared with other treatments, the 1.5% O-carboxymethyl chitosan coating had the best overall preserving effect during storage. O-carboxymethyl chitosan coating could be used in cheese preservation applications and could extend the shelf life of Mongolian cheese. The cheese coated with 1.5% O-carboxymethyl chitosan coating ranked the highest in acceptability at the end of the storage period.

Clinical and microbiological characteristics ofnocardiosis: A 5-year single-center study inCrete, Greece.

Nocardiosis is a rare disease affecting both immunocompromised and immunocompetent hosts, presented in various clinical forms ranging from localized to disseminated infection. Aim of the present study was to investigate the clinical and microbiological characteristics of nocardiosis, antimicrobial resistance profiles, treatment, and outcomes of Nocardia infection over the last 5 years at our institution. The medical records and microbiological data of patients affected by nocardiosis and treated at the university hospital of Heraklion, Crete, Greece, between 2018 and 2022, were retrospectively analyzed. The isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and through sequencing of 16S rRNA. Antimicrobial susceptibility for 17 agents was determined by E-test and results were interpreted according to CLSI guidelines. Among the 28 Nocardia isolates, eight species were identified, with Nocardia brasiliensis being the most prevalent (32.1%), followed by Nocardia otitidiscaviarum (25%), and Nocardia farcinica (14.3%). Skin and soft tissue infections were the most common presentations, noted in 13 (50%) patients, followed by pulmonaryinfection presented in 10 (38.5%) patients. Fifteen patients (57.7%) had at least one underlying disease, and 11 (42.3%) were on immunosuppressive or long-term corticosteroid treatment. Susceptibility rates of linezolid, tigecycline, amikacin, trimethoprim-sulfamethoxazole, moxifloxacin, and imipenem were 100, 100, 96.4, 92.9, 82.1, and 42.9%, respectively. The 26 patients in this study were treated with various antibiotics. Mortality rate was 3.8%, and the patient who died had disseminated infection. Since epidemiology and antimicrobial susceptibility are evolving, continuous surveillance is mandatory in order to initiate appropriate treatment in a timely manner.

Morphotextural, microbiological, and volatile characterization of flatbread containing cricket (Acheta domesticus) powder and buckwheat (Fagopyrum esculentum) flour

The growing awareness of the consumers on the advantages of a proper nutrition is deeply modifying their demands. Hence, the exploitation of innovative ingredients to enrich the nutritional values of staple foods is continuously explored by research institutions and food industries. This paper represents a feasibility study on the use of nonconventional ingredients, including house cricket (Acheta domesticus) powder and buckwheat (Fagopyrum esculentum) flour, for the production of novel flatbread formulations. Experimental flatbread prototypes were evaluated by analyzing microbiological, physico-chemical, textural, colorimetric, and volatile parameters. Microbiological viable counts revealed low levels of bacterial spores in the formulations comprising cricket powder. Water activity results showed adequate values, inhibiting the growth of spoilage and pathogenic bacteria, and preventing the germination of bacterial spores. The addition of cricket powder, influenced textural properties of flatbread samples, characterized by lower hardness values respect to those not containing insects seems likely due to a high content of dietary fiber (chitin from insects). As for the color analysis, flatbread samples added with cricket powder evidenced darker tones respect to those not containing insects, thus resulting visibly comparable with whole grain products. Worthy to mention that the addition of buckwheat flours did not cause hardness reduction or color variation of experimental prototypes. The volatile component analysis highlighted numerous compounds associated with enzymatic activities and nonconventional ingredients. Overall, the results collected demonstrated that cricket powder and buckwheat flour possess a great potential to produce innovative flatbreads.

Microbial Diversity and Abundance in Pulmonary Tissue of Patients with Early-Stage Lung Cancer

Background: The composition of lung tissue microorganisms in patients with different tissue types of lung cancer has not yet been determined. Previous studies have shown changes in the composition of pulmonary microbial flora in patients with lung cancer. Objectives: This study aimed to investigate the differences and correlations in the microbial flora of pulmonary tissue among different histological types of lung cancer. Methods: Samples of tumor and normal lung tissue from 29 patients with early-stage lung cancer were collected. The samples were sequenced using Illumina HiSeq high throughput sequencing technology for 16S rDNA in the V4 region of the bacteria. Also, their microbiological characteristics were detected, and bioinformatics analysis was performed. Results: The results of microbial abundance analysis in the lung tissue of patients with lung cancer showed that the bacterial colony composition of the two tissues was similar, with Proteobacteria, Firmicutes, Anomalococcus, Bacteroides, and Actinobacteria predominating. Analysis of microbial diversity found no difference in α diversity and β diversity between normal lung tissue and tumor tissue. When analyzing patients with adenocarcinoma, the abundance of Micrococcales and Blastomonas was significantly higher in tumor tissue than in normal lung tissue. Conclusions: The composition of microbial flora in different parts of lung tissue of early-stage lung cancer patients is consistent, but the dominant flora varies among different histological types of lung cancer.

Clinical impact of the type VI secretion system on clinical characteristics, virulence and prognosis of Acinetobacter baumannii during bloodstream infection

The type VI secretion system (T6SS) has been regarded as a late-model virulence factor widely distributed in Acinetobacter baumannii (A. baumannii). This study aimed to elucidate the clinical manifestations, the genetic background and microbiological characteristics of A. baumannii isolates causing bloodstream infection (BSI), and assessed the impact of T6SS carrying state on the clinical course. In this study, Clinical samples of A. baumannii causing BSI were collected from a teaching hospital in China from 2016 to 2020 and a retrospective cohort was conducted. Experimental strains were categorized into T6SS positive and negative groups through PCR targeting on hcp gene. The antimicrobials sensitivity test, virulence genes, biofilm formation ability, serum resistance of A. baumannii strains and Galleria mellonella infection model were investigated. Independent risk factors for T6SS+ A. baumannii BSI and Kaplan-Meier curve through follow-up survey were analyzed. A total of 182 A. baumannii strains were isolated from patients with BSI during 5 years and the medical records of all patients were retrospectively reviewed. The proportion of T6SS+ isolates was 62.64% (114/182), which exhibited significantly higher resistance rates of commonly used antibacterial drugs compared to T6SS- group. We found that T6SS+ A. baumannii strains had significantly weaker biofilm formation ability compared to T6SS- A. baumannii. Despite no difference in the positivity rate of tested virulence genes in two groups, T6SS+ strains exhibited higher resistance to the serum and increased virulence in vivo compared to T6SS- strains, indicating that T6SS is likely to enhance the survival and invasive capabilities of A. baumannii in vivo. Indwelling catheter, respiratory diseases, ICU history, white blood cell count and percentage of neutrophils increasing were independent risk factors for T6SS+ A. baumannii BSI. At last, the Kaplan-Meier curve confirmed a higher mortality rate associated with T6SS+ A. baumannii BSI, suggesting that the presence of T6SS may serve as a prognostic factor for mortality. In conclusion, our study revealed that T6SS+ A. baumannii exhibited distinct clinical features, characterized by high antimicrobial resistance and enhanced virulence, providing valuable insights for clinical treatment considerations.

Effect of a new sustainable cooling system used during firming and brining on the microbiological, chemical, and sensory characteristics of buffalo mozzarella cheese.

The cooling applied during the firming and brining processes represents an important production step in mozzarella cheese-making. The temperature fluctuations of the cooling water can negatively affect the hygiene, composition, and quality of mozzarella. Some sustainable cooling systems can minimize this problem by using hot process fluids as heat sources to generate refrigerated energy. This study aimed to evaluate the effects of a new cooling system equipped with a water-ammonia absorption chiller (MA) on the characteristics of buffalo mozzarella through a comparative study with products cooled with a traditional ice water chiller (MT). The buffalo mozzarella cheese manufacture was monitored, and the samples were analyzed for chemical, nutritional, microbiological, and sensory characteristics. The MT samples showed an overall weight loss of 7.4% compared to an average of 2.8% for the MA samples. The MT samples were characterized by greater sapidity than the MA ones, which instead showed a higher moisture content that increased juiciness. The microbiological analysis showed a lower concentration of mesophilic bacterial load in the MA samples than in the MT ones [difference of 1 Log (CFU/g)], which is probably due to the low and constant temperatures that reduced the permanence time of the mozzarella in the vats (firming and brining). This study represents a preliminary positive evaluation of the use of this sustainable cooling system for mozzarella cheese, which is useful for dairy plants with an annual cheese production volume sufficient to justify the operating cost of the plant and the annual energy cost.

The epidemiology and microbiological characteristics of infections caused by Gram-negative bacteria in Qatar: national surveillance from the Study for Monitoring of Antimicrobial Resistance Trends (SMART): 2017 to 2019.

The global Study of Monitoring Antimicrobial Resistance Trends (SMART) is a surveillance program for evaluation of antimicrobial resistance (AMR) in Gram-negative bacteria (GNB) from different regions including Gulf countries. To evaluate AMR in GNB from various clinical specimens including microbiological and genetic characteristics for existing and novel antimicrobials. A prospective study was conducted on clinical specimens from Hamad Medical Corporation, Qatar, between 2017 and 2019 according to the SMART protocol. Consecutive GNB from different sites were evaluated including lower respiratory, urinary tract, intrabdominal and bloodstream infections. Over the 3 years study period, 748 isolates were evaluated from the specified sites comprising 37 different GNB outlining four key pathogens: Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Stenotrophomonas maltophilia.For the two major pathogens E. coli and K. pneumoniae, phenotypic ESBL was identified in 55.77% (116/208) compared to 39% (73/187), while meropenem resistance was 3.8% compared to 12.8% and imipenem/relebactam resistance was 2.97% compared to 11.76%, respectively. The overall ceftolozane/tazobactam resistance for E. coli was 9.6% (20/208) compared to 14.97% (28/187) for K. pneumoniae while resistance for ceftazidime/avibactam was 3.65% (5/137) and 5.98% (10/117), respectively. Genomic characteristics of 70 Enterobacterales including 48 carbapenem-resistant, revealed prevalence of β-lactamases from all classes, predominated by blaCXM-15 while carbapenem resistance revealed paucity of blaKPC and dominance of blaOXA-48 and blaNDM resistance genes. Surveillance of GNB from Qatar showed prevalence of key pathogens similar to other regions but demonstrated significant resistance patterns to existing and novel antimicrobials with different underlying resistance mechanisms.

Impact of mixing coriander oil with goat feed on the chemical, microbiological and sensory characterizations of bio rayeb milk

This research aimed to investigate the properties of bio rayeb milk that results from goats fed on feed supplemented with different concentrations of coriander oil. The study design included a control treatment (C) and two coriander oil concentrations, a low level of (0.95%) T1 and a high level of (1.9%) T2. A probiotic starter culture, Direct Vat Set (DVS) of lactobacillus delbrueckii ssp. bulgaricus and streptococcus salivarius ssp. thermophilus in the ratio (1:1) was used to prepare bio rayeb. All treatments were stored at 4 °C for 2 weeks and analyzed on day one and at the end of storage. Results showed that the coagulation time during bio rayeb manufacturing remained consistent at almost 6 h for all batches. However, using a high coriander oil level (1.90%) significantly decreased the apparent viscosity and the content of monounsaturated fatty acids. The DPPH inhibition and the content of monounsaturated fatty acids increased. The electrophoresis chromatogram exhibited a high degree of proteolysis in T2 compared to the control and T1. Microbiologically, yeast, molds, and coliforms were absent in all treatments. Feeding goats on provender supplemented with a low concentration of coriander oil may positively impact the resultant milk's technological and sensorial properties.