Gram-positive Group Research Articles

Microbiological and Chemical Characteristics of Yoghurt Incorporated with Watermelon Rind Powder

Watermelon rind accounts for approximately one-third of the overall fruit mass. It is usually discarded due to its low commercial value. However, it is reported to contain valuable nutrients and is an effective source of pectin that can act as a potential prebiotic. This study aimed to study the effects of watermelon rind powder (WRP) on the growth of probiotic bacteria in yoghurt and its chemical characteristics. Watermelon rind was dried by using a dehydrator and ground into powder form before being incorporated into fresh yoghurt at 2% and 4% w/v. A sample with 0% w/v WRP was prepared as control. The effect of WRP on the growth of probiotic bacteria was determined by MRS plate count. Chemical analyses including titratable acidity, pH and Brix were conducted during the fermentation process. The results showed that the increase in WRP percentage resulted in a significant increase in bacterial growth with 7.20 ± 0.22 log CFU/mL for the control sample as compared to 8.42 ± 0.23 log CFU/mL for sample with 4% WRP after 30 hr of incubation. The fermentation time was also improved with the presence of WRP with a 0.22 h-1 increase in growth rate observed for the sample with 4% WRP as compared to the control sample. Furthermore, samples containing 4% WRP showed the highest increment in titratable acidity (12.47) and the highest percentage in Brix value reduction (51.04%) during the fermentation period as compared to the control sample. Biochemical analysis showed negative values for oxidase and catalase test while positive values were obtained for gram-staining indicating the presence of Lactic acid bacteria from the gram-positive group. This study demonstrates the high potential of WRP in promoting bacterial growth for yoghurt production which is beneficial to the food industry other than promoting the ongoing effort of food waste reduction.

Prevalence of Some Causes of Acne Vulgaris and Susceptibility to Antibiotics Against Pathogenic Bacteria in Wasit Province

Acne vulgaris is an achronic inflammatory disease in adolescents. Staphylococcus epidermidis (S.epidermidis) and staphylococcus aureus (S.aureus) are the most aerobic and anaerobic bacteria that cause acne S.epidermidis is Gram-positive, cocci, facultative aerobic, and coagulase-negative group (CON) of Staphylococci isolated in contrast S.aureus which characterized by present of coagulase tow type of pathogens are cultured on blood agar under aerobically. Since the bacteria can form a biofilm to resist antibiotics, the current study aims to investigate the effect of selected antibiotic acne on the pathogens bacteria to avoid resistance by misuse and/or overuse of the drug. Through this accurate study, the skin samples were obtained from acne lesions from a different site (face, shoulder, back, chest) of a total of 105 patients with acne vulgaris attending the Iraqi Dermatology Clinic at AL-Karama Teaching Hospital in Al-Kut province and 41(74.5%) S. epidermidis and 3(5,5%) S. aureus were the results of aerobic culture, The accurate study was done between July 2023 to February 2024, Samples were cultured on Blood agar, identify the bacteria was performed by staining with Gram stain and trade vitek2 system, antibiotic susceptibility test was done and based on the Clinical and Laboratory Standards Institute (CLSI) 2023. Additionally, biofilm assay using microtiter plate assay MPA, the results of 41(74.5%) S.epidermidis isolates were 24(58.5%) strong,9(22%) moderate,4(9.8%) weak, and only 4(9.8%) non formed. In comparison, all 3(100%) S. aureus were moderate. In the actual study, the results of antibiotic susceptibility detected that all 41(100%) isolates of S. epidermidis were resistant to ceftazidime, amoxicillin, vancomycin, ampicillin, tetracycline, and penicillin, followed by while all 41(100%) isolates were susceptible to doxycycline followed by 37(90%) sensitive to rifampin, 29 (70.7%) ciprofloxacin, and 8 (68.3%) sensitive to azithromycin. Furthermore, all cases of S. aureus (100%) were resistant to ceftazidime, azithromycin, amoxicillin, vancomycin, ampicillin, gentamycin, and penicillin. Conversely, all isolates (100%) were sensitive to doxycycline and clindamycin; however, only 2(66.7%) were sensitive to ciprofloxacin. While (100%) intermediate to rifampin, erythromycin, and tetracycline.

Identification of Microbiota Causing Bromhidrosis in the Axillary

Bromhidrosis is a clinical condition defined by an uncomfortable or unpleasant body odor. Since the apocrine glands are only active during puberty, most bromhidrosis occurs in the apocrine glands in the armpit and occurs when apocrine gland secretions approach the skin's surface, where they undergo various biochemical reactions caused by the presence of microbiota in the axillary skin, resulting in odor in the axilla. This research aims to identify microbiota species in the axilla that can cause bromhidrosis. A laboratory experimental research design with purposive sampling is used in this study. In this study, 60 samples were collected from students aged 15 to 18 years old at a high school in Medan, and the samples were analyzed at the University of North Sumatra Hospital's Microbiology Laboratory. All samples were taken from the right axillary skin swab, a Gram stain was performed, and the identified microbiota isolates were identified. The results of skin smear culture revealed a Gram-positive cocci group in 59 samples (98.3%) and a Gram-positive bacilli group in only one sample (1.7%). The microbiota responsible for bromhidrosis was identified as Staphylococcus hominis spp. hominins (30.4%), Staphylococcus epidermidis (27.8%), Staphylococcus aureus (16.5%), Kocuria kristinae and Staphylococcus haemolyticus (6.3%), Staphylococcus lugdunensis and Staphylococcus saprophyticus. The most common microbiota that causes bromhidrosis in the axilla is Staphylococcis hominis spp. Hominis, Staphylococcus epidermidis, and Staphylococcus aureus.

Large Spontaneous Subcutaneous Abscess Formation due to Finegoldia magna in a Diabetic Patient: A Case Report.

Finegoldia magna is a member of the Gram-positive anaerobic cocci group and constitutes the flora of the skin and other parts of the body. It sometimes colonizes diabetic foot and rarely infects skin or soft tissue of non-immunocompromised patients. Here, we report the case of a severe subcutaneous abscess on the back caused by F. magna involving an immunocompromised patient with poorly controlled diabetes. A 48-year-old woman with diabetes mellitus and anemia associated with uterine fibroids was referred to us with a 1-month history of a skin manifestation on her back, with a body temperature of 35.9°C and blood pressure of 115/73 mm Hg. The manifestation involved a subcutaneous mass of 36 × 45 cm with a foul odor, partly covered with necrotic tissue, which had the appearance of a tortoiseshell-like pattern. Blood examination revealed C-reactive protein of 21.4 mg/dL and hemoglobin A1c of 9.1%. Contrast-enhanced computed tomography showed a subcutaneous abscess with internal emphysema. Emergency debridement was performed, resulting in drainage of foul-smelling gray-green pus. F. magna was detected in the pus and skin tissue. Skin and soft tissue infectious disease caused by F. magna is extremely rare, but the disease tends to become severe once developing in an immunocompromised patient, such as a patient with poorly controlled diabetes. Therefore, physicians should consider F. magna as a causative agent when poorly controlled diabetic patients suffer from severe infectious cutaneous manifestations.

The profile of bacteria isolated from urine culture of adults with urinary tract infection in Yogyakarta 2007-2022

Local data regarding antimicrobial susceptibility patterns of bacteria from urine culture is limited in Indonesia, particularly in Yogyakarta. This study was conducted to provide epidemiology data of bacteria and their resistance profile, including the profile of bacteria that producing extended-spectrum beta-lactamase (ESBL) and carbapenemase in the urine of patients with urinary tract infection (UTI) in Yogyakarta. A descriptive retrospective study was conducted by assessing laboratory records of urine culture from adult patients at the Microbiology Laboratory, Department of Microbiology, Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada, Yogyakarta between 2007 and 2022. Of the 842 urine cultures, 464 (55.11%) isolates were recovered. Among thisolates, 50 (10.78%) were fungi, 67 (14.44%) were Gram-positive bacteria, and 347 (74.78%) were Gram-negative bacteria. Enterococcus sp. (41 (61.19%)) was the most bacteria found in the Gram-positive bacteria group, while Escherichia coli (38.90%) were the most bacteria found in the Gram-negative bacteria group. This study also identified Gram-negative bacteria producing ESBL enzymes (58.70%) and carbapenemases (27.94%). Gram-negative bacteria are the most common bacteria found in urine cultures of adult UTI patients in Yogyakarta, and the resistance profile of these bacteria is concerning.

Contribution of gut microbiota to biodegradation of polystyrene in Tenebrio molitor larvae: Microbiome under antibiotic suppression of Gram-positive, Gram-negative, and fungal microbes

The discovery of plastic biodegradation by insects such as Tenebrio molitor larvae has been well known, however, understanding of the roles of larval gut microorganisms is still very limited. The contribution of the gut microbes belonging to respective Gram-positive (G+), Gram-negative (G−), and fungal (F) groups remains unclear. In this study, we tested polystyrene (PS) biodegradation by T. molitor larvae under three selective antibiotics i.e., gentamicin sulfate (GMS) against G− bacteria, ampicillin (AMP) against G+ bacteria and nystatin (NS) against fungi. The larvae consumed and biodegraded PS foams with Mn 86.381 kDa and Mw 181.176 kDa under antibiotic suppressions at reduced rates versus control (CK) with a sequence of CK>GMS>AMP>NS group. Specifically, only NS group showed a significant decreased in consumption compared to the control. The gut microbial counts decreased with GMS, AMP, or NS addition during the PS feeding. The respective gut microbial counts decreased by 103 to 104 with GMS, AMP, or NS addition PS feeding. Analyses of DSC, TGA, FTIR confirmed oxidation and biodegradation in the presence of antibiotics. The ingested PS polymers were depolymerized and mass reduction with negative influence in the order of NS<AMP<GMS. The negative impact of antibiotic suppression on PS biodegradation process was as follows: anti-fungi reagent > anti-G+ bacteria > anti- G− bacteria. Changes in chemical functional groups are probably related to certain gut microbes, such as the fungal genus of Candida, and bacterial genera of unclassified Enterobacteriaceae and Lactobacillus. Our findings provided new insights into the mechanisms of the biodegradation of plastics in insects.

Evaluation of cardiac output in neonatal sepsis

Background: Neonatal sepsis is a clinical syndrome characterized by signs and symptoms of infection with or without accompanying bacteremia in the 1st month of life imposing significant cardiovascular compromise which poses a huge burden of morbidity. The essential objective of functional neonatal echocardiography is to recognize features of cardiovascular compromise earlier and help in timely institution of management. This study provides an overview regarding the variability of cardiac output (CO) in neonates with culture-positive sepsis. Aims and Objectives: The aims and objectives of the study are to assess the variability of CO in term neonates with Gram-positive sepsis and Gram-negative sepsis. Materials and Methods: The observational cross-sectional study was conducted in the Department of Paediatrics for 18 months in a tertiary care center. 2D echocardiography was performed on all the neonates who came positive for sepsis screen within the first 2 days of institution of antibiotics. CO was calculated from the echocardiographic finding of Aortic Root Diameter (d), Velocity Time Integral, and Heart Rate recorded at the same time. Normal range of left ventricular output has been defined as 150–300 mL/kg/min each. Results: In Gram-negative group, the mean CO (Mean±SD) of patients was 386.4545±34.2284 mL/kg/min while in Gram-positive group, the mean CO (Mean±SD) of patients was 345.1532±37.6044 mL/kg/min and the variation stands significant at P&lt;0.0001. Conclusion: This research confers about hyperdynamic circulatory status of neonatal sepsis as reflected by increased CO beyond the normal limit in septic neonates. On comparison, a strikingly higher CO was observed in Gram-negative sepsis group than Gram-positive group.

Emergent emm4 group A Streptococcus evidences a survival strategy during interaction with immune effector cells.

The major gram-positive pathogen group A Streptococcus (GAS) is a model organism for studying microbial epidemics as it causes waves of infections. Since 1980, several GAS epidemics have been ascribed to the emergence of clones producing increased amounts of key virulence factors such as streptolysin O (SLO). Herein, we sought to identify mechanisms underlying our recently identified temporal clonal emergence among emm4 GAS, given that emergent strains did not produce augmented levels of virulence factors relative to historic isolates. By creating and analyzing isoallelic strains, we determined that a conserved mutation in a previously undescribed gene encoding a putative carbonic anhydrase was responsible for the defective in vitro growth observed in the emergent strains. We also identified that the emergent strains survived better inside macrophages and killed macrophages at lower rates than the historic strains. Via the creation of isogenic mutant strains, we linked the emergent strain "survival" phenotype to the downregulation of the SLO encoding gene and upregulation of the msrAB operon which encodes proteins involved in defense against extracellular oxidative stress. Our findings are in accord with recent surveillance studies which found a high ratio of mucosal (i.e., pharyngeal) relative to invasive infections among emm4 GAS. Since ever-increasing virulence is unlikely to be evolutionarily advantageous for a microbial pathogen, our data further understanding of the well-described oscillating patterns of virulent GAS infections by demonstrating mechanisms by which emergent strains adapt a "survival" strategy to outcompete previously circulating isolates.

Cerebrospinal Fluid Neutrophil Gelatinase-Associated Lipocalin as a Novel Biomarker for Postneurosurgical Bacterial Meningitis: A Prospective Observational Cohort Study.

Postneurosurgical bacterial meningitis (PNBM) was a significant clinical challenge, as early identification remains difficult. This study aimed to explore the potential of neutrophil gelatinase-associated lipocalin (NGAL) as a novel biomarker for the early diagnosis of PNBM in patients who have undergone neurosurgery. A total of 436 postneurosurgical adult patients were enrolled in this study. Clinical information, cerebrospinal fluid (CSF), and blood samples were collected. After the screening, the remaining 267 patients were divided into the PNBM and non-PNBM groups, and measured CSF and serum NGAL levels to determine the diagnostic utility of PNBM. Subsequently, patients with PNBM were categorized into gram-positive and gram-negative bacterial infection groups to assess the effectiveness of CSF NGAL in differentiating between these types of infections. We analyzed the changes in CSF NGAL expression before and after anti-infection treatment in PNBM. Finally, an additional 60 patients were included as an independent validation cohort to further validate the diagnostic performance of CSF NGAL. Compared with the non-PNBM group, CSF NGAL was significantly higher in the PNBM group (305.1 [151.6-596.5] vs 58.5 [30.7-105.8] ng/mL; P < .0001). The area under the curve of CSF NGAL for diagnosing PNBM was 0.928 (95% CI: 0.897-0.960), at a threshold of 119.7 ng/mL. However, there was no significant difference in serum NGAL between the 2 groups (142.5 [105.0-248.6] vs 161.9 [126.6-246.6] ng/mL, P = .201). Furthermore, CSF NGAL levels were significantly higher in patients with gram-negative bacterial infections than those with gram-positive bacteria ( P = .023). In addition, CSF NGAL levels decrease after treatment compared with the initial stage of infection ( P < .0001). Finally, in this validation cohort, the threshold of 119.7 ng/mL CSF NGAL shows good diagnostic performance with a sensitivity and specificity of 90% and 80%, respectively. CSF NGAL holds promise as a potential biomarker for the diagnosis, early drug selection, and efficacy monitoring of PNBM.

The legal norms of the European Union regarding the prevention of foodborne listeriosis, consumer risk assessment, diagnostic methods, and identification of Listeria spp.

Listeria monocytogenes is a common bacterium due to its high adaptability. The pathogen can survive in adverse conditions, making monitoring very difficult. Listeria monocytogenes belongs to the Gram-positive group of bacteria that are relatively anaerobic and exhibit a characteristic tipping movement. There are 6 species in the genus Listeria, but only one – Listeria monocytogenes, under favorable conditions, can cause a disease called listeriosis in humans. The pathogen can grow in aerobic and anaerobic conditions at 0 to 40 °C temperatures. Can survive in adverse conditions, for example, low or high temperature, with a wide range of pH fluctuations or high salinity of the product. Thus, refrigeration conditions (0–4 °C), where we often store manufactured food or raw materials necessary for production, can be ideal for developing Listeria monocytogenes. The pathogen is transmitted through water, soil, infected plants, food, feed, sewage (feces), and meat from farmed or wild animals. To prevent the spread of Listeria monocytogenes. Food manufacturers must comply with national and European Union legal norms regarding producing and selling microbiologically safe food products. Commission Regulation (EC) No. 2073/2005 defines in detail the criteria for limiting the number of Listeria monocytogenes, which must meet the maximum permissible standards according to the type and consumer purpose of the food product. Adherence to the rules of correct hygiene steps in agrarian firms guarantees that products and raw materials of animal and plant origin will be of proper quality with excellent sanitary and hygienic indicators. The mandatory introduction of the HACCP system is an effective tool for analyzing the risks associated with the processing and production of food products, which makes it possible to guarantee freshness, quality, and safety. HACCP must be applied throughout the entire production chain up to the final consumption and is based primarily not on the control of the final product, but on the prevention of risks.

СОВРЕМЕННЫЕ ТЕНДЕНЦИИ АНТИБИОТИКОУСТОЙЧИВОСТИ ПАТОГЕННЫХ МИКРООРГАНИЗМОВ ПАЦИЕНТОВ ХИРУРГИЧЕСКОГО ПРОФИЛЯ

Background. To carry out adequate antibacterial therapy directed against pathogenic microflora in patients with surgical infection it is necessary to take into account indicators of antibiotic resistance of leading etiological agents. The aim of the work is to study the spectrum and current dynamics of changes in antibiotic resistance of purulent pathogens in soft tissues of surgical patients. Material and methods. An analysis of the results of antibiotic resistance of the seeded leading microflora in patients with purulent processes of soft tissues was made. Results. Isolates of Staphylococcus aureus from surgical patients are characterized by high resistance to all β-lactam antibiotics, the combination drug trimethoprim-sulfamethoxazole, and macrolides. The resistance of Klebsiella pneumoniae and Proteus mirabilis to all studied β-lactam antibiotics, as well as fluoroquinolones, aminoglycosides, tetracyclines, nitrofurans, and chloramphenicol ranges from 37 to 100%. Escherichia coli resistance to β-lactams, fluoroquinolones, carbapenems, and aminoglycosides reaches 50-73%. A high level of antibacterial resistance is also characteristic of other bacteria most often cultured in surgical patients. Conclusions. The most frequently cultured strains of both gram-positive and gram-negative groups of microorganisms from surgical patients are characterized by a high level of antibacterial resistance, reaching 100%. Currently, cases of polyantibiotic resistance and resistance even to reserve antibiotics are not uncommon. All this dictates the need to search for new classes of substances that have an antimicrobial effect, and metal nanoparticles may be one of them.

Group A Streptococcus Pili-Roles in Pathogenesis and Potential for Vaccine Development.

The Gram-positive human pathogen Group A Streptococcus (GAS, Streptococcus pyogenes) employs an arsenal of virulence factors that contribute to its pathogenesis. The pilus is an important factor that enables the pathogen to adhere to and colonize host tissues. Emerging research in pilus function shows that pili's involvement in establishing infection extends beyond host adhesion. The diversity of GAS pilus types reflect the varying characteristics identified in different pili. With the development of new experimental systems and animal models, a wider range of biological functions have been explored. This brief review summarizes recent reports of new functions in different GAS pilus types and the methodologies that contributed to the findings. The established importance of the pilus in GAS pathogenesis makes this surface structure a promising vaccine target. This article also reviews recent advancements in pilus-based vaccine strategies and discusses certain aspects that should be considered in vaccine development according to the newly defined properties of pili.

BACTERIAL PROFILE AND ANTIBIOTIC SUSCEPTIBILITY TEST AMONG DIABETES MELLITUS PATIENTS WITH GANGRENE IN SURABAYA

Background: Gangrene is a severe complication of damaged tissue that can occur in people with Diabetes Mellitus (DM), putting them at risk for bacterial infection. A pus culture can show diabetic gangrene patients' infecting bacteria. Purpose: Determine the prevalence of infection-causing bacteria and antibiotic sensitivity tests in diabetic gangrene patients at Haji Regional General Hospital, East Java Province, for January-December 2021. Method: The method used in this study is observational analytical cross-sectional, which is based on secondary data and is analyzed using the percentage formula and Chi-Square test. Result: The data obtained from 39 patients revealed 29 (74.4%) positive patients for bacterial infection. The Gram-negative bacteria was found to cause infection more frequently (72.41%) than the Gram-positive bacteria (27.59%). The prevalence of Gram-negative bacteria species most frequently from Escherichia coli (ESBL) 13.79% (4/29), Klebsiella pneumoniae 10.35% (3/29), Proteus mirabilis 10.35% (3/29). While the dominant Gram-positive bacteria a Methicillin-Resistant Staphylococcus aureus (MRSA) 10.35% (3/29). The antibiotic sensitivity test showed that Gram-negative group were susceptible to ertapenem, meropenem, amikacin, gentamicin, and piperacillin tazobactam while resistant to ampicillin and cefazolin. The antibiotic sensitivity tests showed that the Gram-positive group was susceptible to linezolid, vancomycin, and tigecycline while resistant to tetracycline and ciprofloxacin. Conclusion: It is important to screen the bacterial profile causing gangrene and their antibiotic susceptibility pattern in DM patients in order to give proper treatment to DM patients.

Identification of Air Bacteria Using Gram Style Methods in The Integrated Laboratory of Bina Mandiri University Gorontalo

Microbiology is the study of microorganisms which cannot be seen with the naked eye to examine what is contained in microorganisms. To see microorganisms, it is necessary to have gram stain which is one of the most widely used procedures to characterize many bacteria. This study aims to understand the chemical and theoretical basis for the differential staining procedure as well as the procedure for differentiating between the two main groups of bacteria namely gram positive and gram negative. The method used in this research is the experimental method. The experimental method is a method used in laboratory research. The purpose of this experimental method is to determine the consequences of a treatment given deliberately by the researcher. In addition, a qualitative descriptive approach was used to provide an overview of airborne bacteria by using the gram stain method. The results showed that samples of NA media in airborne bacteria were carried out using a microscope at 10x magnification, which aims to see the color of the bacteria, in the gram staining experiment that has been carried out produces a purple color. This shows that these bacteria are included in the gram-positive bacteria group, as well as the results of the type of bacteria obtained in the gram stain experiment, namely E. coli bacteria which has aform monobacillus.

Procalcitonin and C-reactive protein as diagnostic biomarkers in COVID-19 and Non-COVID-19 sepsis patients: a comparative study

BackgroundThis study aimed to assess and compare procalcitonin (PCT) and C-reactive protein (CRP) levels between COVID-19 and non-COVID-19 sepsis patients. Additionally, we evaluated the diagnostic efficiency of PCT and CRP in distinguishing between Gram-positive (GP) and Gram-negative (GN) bacterial infections. Moreover, we explored the associations of PCT with specific pathogens in this context.MethodsThe study included 121 consecutive sepsis patients who underwent blood culture testing during the COVID-19 epidemic. PCT and CRP were measured, and reverse transcriptase-polymerase chain reaction (RT-PCR) was employed for the detection of COVID-19 nucleic acid. The Mann-Whitney U-test was used to compare PCT and CRP between the COVID-19 and non-COVID-19 groups. Receiver operating characteristic (ROC) curves were generated to compare PCT and CRP levels in the GN group versus the GP group for assessing the diagnostic efficiency. The kruskal-Wallis H test was applied to assess the impact of specific pathogen groups on PCT concentrations.ResultsA total of 121 sepsis patients were categorized into a COVID-19 group (n = 25) and a non-COVID-19 group (n = 96). No significant differences in age and gender were observed between the COVID-19 and non-COVID-19 groups. The comparison of biomarkers between these groups showed no statistically significant differences. The optimal cut-off values for PCT and CRP in differentiating between GP and GN infections were 1.03 ng/mL and 34.02 mg/L, respectively. The area under the ROC curve was 0.689 (95% confidence interval (CI) 0.591–0.786) for PCT and 0.611 (95% CI 0.505–0.717) for CRP. The diagnostic accuracy was 69.42% for PCT and 58.69% for CRP. The study found a significant difference in PCT levels among specific groups of pathogens (P < 0.001), with the highest levels observed in Escherichia coli infections. The frequency of Staphylococcus spp. positive results was significantly higher (36.0%) in COVID-19 compared to non-COVID-19 sepsis patients (P = 0.047).ConclusionSepsis patients with COVID-19 revealed a significantly higher culture positivity for staphylococcus spp. than the non-COVID-19 group. Both PCT and CRP showed moderate diagnostic efficiency in differentiating between GP and GN bacterial infections. PCT showed potential utility in identifying E. coli infections compared to other pathogens.

Clinical value of heparin-binding protein in adult bacterial intracranial infection.

The accurate and sensitive diagnosis of intracranial infection continues to pose a critical challenge. This study aimed to probe into the clinical value of heparin binding protein (HBP) in bacterial intracranial infection. Patients suspected of having bacterial intracranial infection and admitted to Shanghai General Hospital from November 2021 to November 2023 were selected as study subjects and divided into an infected group and a non-infected group. The receiver operating characteristic (ROC) curve was constructed to compare the diagnostic accuracy of HBP, procalcitonin (PCT), and C-reactive protein (CRP), as well as their value in differentiating Gram-positive bacteria and Gram-negative bacterial infections. According to the results of bacterial identification, the infected groups were divided into a Gram-negative bacteria group (n = 142) and a Gram-positive bacteria group (n = 128), while the non-infected group comprised 120 patients after neurosurgery involving dura opening. Statistically significant differences were observed in the levels of HBP, PCT, and CRP between the infected group and the non-infected group (all p< 0.05). Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of HBP was 0.935, and the AUCs of PCT and CRP were 0.931 and 0.863, respectively. In the comparison of HBP, PCT, and CRP levels in the Gram-negative bacteria and Gram-positive bacteria groups, the AUCs were 0.816, 0.602, and 0.591, respectively. When the cutoff value of HBP was 72.34 ng/mL, its specificity reached 96.1% and its sensitivity was 57.8%. When PCT and CRP levels were less than 1.67 ng/mL and 23.12 ng/mL, respectively, both the sensitivity (52.3%, 53.1%) and specificity (66.9%, 59.9%) were relatively low. HBP, PCT, and CRP can be employed as diagnostic indicators for bacterial intracranial infection. HBP (>72.34 ng/mL) can act as an important index for the diagnosis of Gram-negative bacteria in patients with intracranial infection.

Diagnostic Potential of Anterior Segment Optical Coherence Tomography Scans for Pseudomonas Keratitis.

The purpose of this study was to investigate the diagnostic value of anterior segment optical coherence tomography (AS-OCT) scans for Pseudomonas keratitis. Patients with treatment-naïve keratitis underwent AS-OCT imaging. The following parameters were evaluated: corneal thickness (CT), infiltrate thickness (IT), infiltrate diameter (ID), tissue loss/gain, entropy, and distance of the lesion from the corneal pupillary center. Three different OCT devices were used for the analysis. The relationship between the detected pathogen and the OCT patterns was analyzed. Nineteen eyes of 19 patients were included in the analysis: seven cases in the Pseudomonas group and 12 cases in the Gram-positive group. The mean (SD) values for the Pseudomonas and Gram-positive groups, respectively, were as follows: CT, 834 µm (165 µm) and 760 µm (120 µm); IT, 290 µm (152 µm) and 287 µm (84 µm); ID, 2067 µm (1470 µm) and 1307 µm (745 µm); distance to center, 3.0 mm (1.2 mm) and 3.0 mm (1.6 mm); epithelial defect, 1193 µm (586 µm) and 484 µm (615 µm); tissue gain, +31% (19%) and +10% (12%); and entropy level, 4.0 (0.8) and 3.9 (1.1). This study introduces novel insights by identifying specific OCT parameters that distinguish Pseudomonas keratitis, including a 30% tissue gain. These findings align with earlier research that underscores the potential of OCT in differentiating various pathogens causing keratitis. The findings of this study could be used to develop new diagnostic strategies for Pseudomonas keratitis. The OCT findings could be used to develop new biomarkers for the infection.

Concurrent Brain Subregion Microgliosis in an HLA-II Mouse Model of Group A Streptococcal Skin Infection.

The broad range of clinical manifestations and life-threatening infections caused by the Gram-positive bacterium, Streptococcus pyogenes or Group A Streptococcus (GAS), remains a significant concern to public health, with a subset of individuals developing neurological complications. Here, we examined the concurrent neuroimmune effects of subcutaneous GAS infections in an HLA-Class II (HLA) transgenic mouse model of subcutaneous GAS infection. To investigate changes in the skin-brain axis, HLA-DQ8 (DQA1*0301/DQB1*0302) mice (DQ8) were randomly divided into three groups: uninfected controls (No Inf), GAS infected and untreated (No Tx), and GAS infected with a resolution by clindamycin (CLN) treatment (CLN Tx) (10 mg/kg/5 days) and were monitored for 16 days post-infection. While the skin GAS burden was significantly reduced by CLN, the cortical and hippocampal GAS burden in the male DQ8 mice was not significantly reduced with CLN. Immunoreactivity to anti-GAS antibody revealed the presence of GAS bacteria in the vicinity of the neuronal nucleus in the neocortex of both No Tx and CLN Tx male DQ8 mice. GAS infection-mediated cortical cytokine changes were modest; however, compared to No Inf or No Tx groups, a significant increase in IL-2, IL-13, IL-22, and IL-10 levels was observed in CLN Tx females despite the lack of GAS burden. Western blot analysis of cortical and hippocampal homogenates showed significantly higher ionized calcium-binding adaptor-1 (Iba-1, microglia marker) protein levels in No Tx females and males and CLN Tx males compared to the No Inf group. Immunohistochemical analysis showed that Iba-1 immunoreactivity in the hippocampal CA3 and CA1 subregions was significantly higher in the CLN Tx males compared to the No Tx group. Our data support the possibility that the subcutaneous GAS infection communicates to the brain and is characterized by intraneuronal GAS sequestration, brain cytokine changes, Iba-1 protein levels, and concurrent CA3 and CA1 subregion-specific microgliosis, even without bacteremia.

Rapid and Green Classification Method of Bacteria Using Machine Learning and NIR Spectroscopy.

Green Chemistry is a vital and crucial instrument in achieving pollution control, and it plays an important role in helping society reach the Sustainable Development Goals (SDGs). NIR (near-infrared spectroscopy) has been utilized as an alternate technique for molecular identification, making the process faster and less expensive. Near-infrared diffuse reflectance spectroscopy and Machine Learning (ML) algorithms were utilized in this study to construct identification and classification models of bacteria such as Escherichia coli, Salmonella enteritidis, Enterococcus faecalis and Listeria monocytogenes. Furthermore, divide these bacteria into Gram-negative and Gram-positive groups. The green and quick approach was created by combining NIR spectroscopy with a diffuse reflectance accessory. Using infrared spectral data and ML techniques such as principal component analysis (PCA), hierarchical cluster analysis (HCA) and K-Nearest Neighbor (KNN), It was feasible to accomplish the identification and classification of four bacteria and classify these bacteria into two groups: Gram-positive and Gram-negative, with 100% accuracy. We may conclude that our study has a high potential for bacterial identification and classification, as well as being consistent with global policies of sustainable development and green analytical chemistry.

Potential of chambá (Justicia Pectoralis Jacq.) leaves extracts as a source of bioactive compounds and natural antimicrobial agent

This study aimed to produce different chambá (Justicia pectoralis Jacq.) extracts, determinate their biocompounds and antimicrobial activity against several foodborne bacterias. Aqueous and hydroalcoholic extracts were prepared using the decoction and maceration method, respectively, and were submitted to cytotoxicity analysis. The samples were submitted to bioactive compound analysis and antimicrobial tests. The effects of the extract on the bacterial cell structures were visualized using Transmission Electron Microscope. Between the samples, the aqueous extract presented higher levels of umbelliferone (8.99 mg/g), total phenolic compounds (17.7 g AGE/100g) and antioxidant activity (765.3 μM TE/g) compared hydroalcoholic extracts. All extracts presented antimicrobial activity against Gram-Positive bacteria group, being the aqueous sample the one most effective presenting the lowest values for minimum inhibitory (MIC) and bactericidal (MIB) concentrations for all microorganisms evaluated, highlighting its action against Staphyloccocus aureaus (MIC = 0.84 and MIB = 1). The bactericidal action of the aqueous extract against the bacteria was observed by the microphotographs with evidenced by a rupture of the bacterial cell wall caused by the exposition to phenolics presented in the extract. Thus, this research demonstrated that beyond being a source of phenolics, chambá presents great potential as a new natural antimicrobial agent, which reinforces the development of more studies to evaluate its effective application in food systems.