Brain Heart Infusion Research Articles

Antibacterial and Antibiofilm Effects of L-Carnitine-Fumarate on Oral Streptococcal Strains Streptococcus mutans and Streptococcus sobrinus.

Streptococcus mutans is a major pathogenic habitant of oral caries. Owing to its physiological and biochemical features, it prevails in the form of plaque biofilm together with another important mutans streptococci species, Streptococcus sobrinus. Both species are considered as initiators of cavity lesions, and biofilm is essential to the dental caries process. Compared with the planktonic populations, the biofilm form has higher resistance to environmental conditions and antibiotics. Dental plaques also secure the long-term survival of microorganisms and protection from any stress conditions. To address the need for new antibiofilm agents, we have focused on L-carnitine-fumarate, a fumarate-conjugated quaternary ammonium compound. Using the macro-broth susceptibility testing method, we established its MIC value as 6.0 mg/mL. The MBC value, determined from the broth dilution minimum inhibitory concentration test by sub-culturing it to BHI agar plates, was established as 7.0 mg/mL. Antibiofilm efficacy was tested in 96-well plates coated with saliva using BHI broth supplemented with 1% sucrose as a standard approach. The obtained results allowed us to assess the MIBC as 7.5 mg/mL and the MBBC value as 10.0 mg/mL. The latter concentration also caused approximately 20% eradication of pre-existing biofilm. EPS-rich matrix, forming the core of the biofilm and enabling a confined acidic microenvironment, was also examined and confirmed the effectiveness of 10.0 mg/mL L-carnitine-fumarate concentration in inhibiting EPS formation. Furthermore, the anti-adherent and anti-aciduric impacts of L-carnitine-fumarate were investigated and revealed significant inhibitory effects at sub-MIC concentrations. The influence of L-carnitine-fumarate on the phosphotransferase system was investigated as well. Our results provide a new insight into the antibacterial potential of L-carnitine-fumarate as a valuable compound to be considered for alternative or adjunct anti-caries and antibiofilm preventive approaches.

Degree of Contamination of Gutta-Percha Points by Staphylococcus aureus (MRSA/MSSA) Strains.

We performed an in vitro analysis of the contamination of GP points, regarding the strains of Methicillin-resistant (MRSA) and Methicillin-sensitive (MSSA) Staphylococcus aureus, using classical microbiology methods and molecular biology techniques. Gutta-Percha points of two different brands from opened packages (already in use for 1 month) were collected for analysis. The assessment involved incubating the GP points in Brain Heart Infusion (BHI) medium to detect microbial growth. Growing microorganisms were plated on a selective and differential chromogenic medium for MRSA/MSSA strains, and the identification of isolates was confirmed by Polymerase Chain Reaction (PCR). In the case of microbial growth, the GP point was submitted to a disinfection protocol. From the 315 collected GP points, only 6 (1.9%) resulted in being positive for microbial growth. After confirmation by PCR, only one sample of the six GP points was contaminated by MRSA, and the remaining five were MSSA-contaminated. The disinfection protocol was effective in all contaminated GP points. The Gutta-Percha points from opened pre-sterilized packages showed a very low degree of contamination by MRSA/MSSA. However, the detection of MSSA and MRSA strains raises concerns about potential contamination in dental clinic environments, and this risk cannot be considered negligible.

Relationship between deltamethrin resistance and gut symbiotic bacteria of Aedes albopictus by 16S rDNA sequencing

BackgroundAedes albopictus is an important vector for pathogens such as dengue, Zika, and chikungunya viruses. While insecticides is the mainstay for mosquito control, their widespread and excessive use has led to the increased resistance in Ae. albopictus globally. Gut symbiotic bacteria are believed to play a potential role in insect physiology, potentially linking to mosquitoes’ metabolic resistance against insecticides.MethodsWe investigated the role of symbiotic bacteria in the development of resistance in Ae. albopictus by comparing gut symbiotic bacteria between deltamethrin-sensitive and deltamethrin-resistant populations. Adults were reared from field-collected larvae. Sensitive and resistant mosquitoes were screened using 0.03% and 0.09% deltamethrin, respectively, on the basis of the World Health Organization (WHO) tube bioassay. Sensitive and resistant field-collected larvae were screened using 5 × LC50 (lethal concentration at 50% mortality) and 20 × LC50 concentration of deltamethrin, respectively. Laboratory strain deltamethrin-sensitive adults and larvae were used as controls. The DNA of gut samples from these mosquitoes were extracted using the magnetic bead method. Bacterial 16S rDNA was sequenced using BGISEQ method. We isolated and cultured gut microorganisms from adult and larvae mosquitoes using four different media: Luria Bertani (LB), brain heart infusion (BHI), nutrient agar (NA), and salmonella shigella (SS).ResultsSequencing revealed significantly higher gut microbial diversity in field-resistant larvae compared with field-sensitive and laboratory-sensitive larvae (P < 0.01). Conversely, gut microorganism diversity in field-resistant and field-sensitive adults was significantly lower compared with laboratory-sensitive adults (P < 0.01). At the species level, 25 and 12 bacterial species were isolated from the gut of field resistant larvae and adults, respectively. The abundance of Flavobacterium spp., Gemmobacter spp., and Dysgonomonas spp. was significantly higher in the gut of field-resistant larvae compared with sensitive larvae (all P < 0.05). Furthermore, the abundance of Flavobacterium spp., Pantoea spp., and Aeromonas spp. was significantly higher in the gut of field-resistant adults compared with sensitive adults (all P < 0.05). The dominant and differentially occurring microorganisms were also different between resistant larval and adult mosquitoes. These findings suggest that the gut commensal bacteria of Ae. albopictus adults and larvae may play distinct roles in their deltamethrin resistance.ConclusionsThis study provides an empirical basis for further exploration of the mechanisms underlying the role of gut microbial in insecticide resistance, potentially opening a new prospect for mosquito control strategies.Graphical

Design of an agro-industrial by-products-based media for the production of probiotic bacteria for fish nutrition

Probiotic production in commercial culture media is expensive, so, it is necessary to design culture media based on “low-cost” components like agro-industrial by-products. Therefore, this study aimed to design an agro-industrial by-product-based culture media using whey, sugarcane molasses, and palm kernel cake as components to produce Lactococcus lactis A12, Priestia megaterium M4, and Priestia sp. M10 isolated from Nile tilapia (Oreochromis niloticus) associated gut microbiota. Higher bacterial concentrations were achieved at high whey concentrations and low concentrations of sugarcane molasses and palm kernel cake (PKC) using agitation. The optimal conditions were whey, 3.84% w/v; sugarcane molasses, 7.39% w/v; PKC, 0.77% w/v; and agitation speed, 75 RPM. Bacterial growth under optimal conditions was compared to that in commercial Brain–Heart Infusion (BHI) broth. L. lactis A12 showed similar growth in the optimal media and BHI. The estimated cost of the culture media based on component prices was USD $ 3.01/L, which is 86.93% lower than BHI broth (USD $ 23.04/L). It was possible to design a “low-cost agro-industrial by-product-based culture media to produce L. lactis A12 and the two Priestia species under monoculture conditions.

Monitoring Multi-Drug Resistant Klebsiella pneumoniae in Kitagata Hot Spring, Southwestern Uganda: A Public Health Implication.

The concerning frequency of K. pneumoniae in various recreational settings, is noteworthy, especially regarding multi-drug resistant (MDR) strains. This superbug is linked to the rapid spread of plasmids carrying these resistance genes. The objective of this study was to evaluate the spatiotemporal prevalence of MDR-K. pneumoniae in the Kitagata hot spring, Southwestern Uganda. A laboratory-based descriptive longitudinal study was conducted between May and July 2023. During rainy and dry seasons, we collected eighty water samples in the morning and evening from the hot spring. The temperature at each point was measured prior to sample collection, and two samples were obtained at varying depths. 5 mL of each homogenized sample were pre-enriched in brain heart infusion broth, and subsequently in both blood and violet red bile agar. The Kirby-Bauer disk diffusion method was performed, followed by the detection of carbapenemase (CR) and extended-spectrum β-lactamase (ESBL) production. Polymerase chain reaction showed resistance genes viz. bla TEM, bla CTX-M and bla KPC. Data were analyzed using SPSS-20 to obtain chi-square tests and regression analysis. K. pneumoniae accounted for 30.0% of isolates obtained from Kitagata hot springs, with all isolates classified as multi-drug resistant. All isolates were resistant to ampicillin, rifampicin, ceftazidime, and azithromycin (79.2%). Additionally, 95.8% of isolates harbored bla TEM gene alone and both bla TEM and bla CTX genes, followed by bla KPC alone (33.3%), with 25% harboring all three resistance genes. During the dry season, K. pneumoniae had a higher prevalence (35.0%) compared to the wet season (25.0%). The prevalence of MDR-K. pneumoniae significantly increased over the course of the study. The presence of the three studied resistance genes in the isolates showed a positive correlation with the second phase of sample collection and the dry season but exhibited a negative correlation with temperature, except for isolates harboring either bla TEM alone or bla TEM+KPC+CTX genes. Kitagata hot spring serves as a hotspot for continuous dissemination and acquisition of MDR-K. pneumoniae harboring resistance genes that encode for ESBL and CR production. The healthcare sector ought to implement an ongoing monitoring and surveillance system as well as robust antimicrobial resistance stewardship programs aimed at delivering health education to the community.

Comparative evaluation of antibacterial efficacy of nitrofurantoin, chitosan, and calcium hydroxide in combination with propylene glycol as an intracanal medicament against endodontic pathogen - An in vitro study.

The objective is to evaluate and compare the antibacterial efficacy of nitrofurantoin, chitosan, and calcium hydroxide (Ca(OH)2) in combination with propylene glycol (PG) as an intracanal medicament against endodontic pathogens. Fifty-two extracted single-rooted maxillary and mandibular anterior teeth and premolars were selected. The root canals were enlarged using Protaper universal rotary files. Clinical isolates of microorganisms collected from retreatment cases were used. Bacterial isolates obtained from infected root canals were introduced into brain-heart infusion (BHI) broth. Incubation of samples for 14 days was carried out to facilitate the development of mature biofilms. Intracanal medicaments were divided into four groups: Group 1 - Nirofurantoin+20% PG, Group 2 - Chitosan+20% PG, Group 3 - Ca(OH)2 + 20% PG, and Group 4 - 20% PG. The prepared root samples were incubated for 7 days. After collecting dentin samples, they were placed in a phosphate-buffered saline solution. Serial dilutions were then performed, and each dilution was plated on BHI agar. The plates were incubated for 24 h at 37°C. The antibacterial efficacy was assessed by calculating the percentage of remaining colony-forming units. Antibacterial efficacy of chitosan paste was significantly higher followed by nitrofurantoin as compared to other groups when used as an intracanal medicament. In the root-canal biofilm model, the combination of chitosan and PG demonstrated a significant reduction in the viability of endodontic pathogens when employed as intracanal medication for 7 days. This suggests its potential as an effective intracanal medicament for endodontic retreatment.

Preliminary investigations of microbiologically influenced corrosion of 304 stainless steel by anaerobic Clostridioides difficile biofilm

Clostridioides difficile is a pathogenic anaerobe that potentially causes microbiologically influenced corrosion (MIC). Coupons of 304 stainless steel (SS) were incubated with C. difficile in deoxygenated brain heart infusion supplement medium. After a 7-d incubation, C. difficile biofilms were observed on the 304 SS coupon surfaces. The sessile cell count on 304 SS coupons were (1.9 ± 0.5) × 107 cells/cm2. It was found that this high-grade SS did not suffer measurable corrosion weight loss and pitting. X65 carbon steel was used to verify C. difficile bio-corrosivity. A 7-d weight loss of 0.9 ± 0.2 mg/cm2 was found on X65 coupons with the same incubation condition, which manifested as uniform corrosion. 13%Cr steel, also known as 420 SS which is a low-grade SS that is prone to pitting, was used to verify pitting by C. difficile. A 15.2 μm pit was observed after 26 d of incubation. Electrochemical tests were conducted in a 10 mL biofilm/MIC test kit. The electrochemical analysis of electron mediator injection indicated that MIC of 304 SS by C. difficile belongs to extracellular electron transfer-MIC. A 100 ppm (w/w) tetrakis (hydroxymethyl)phosphonium sulfate (a green biocide) injection test proved that it is a suitable disinfectant for C. difficile.

Quantitative determination of the antibacterial activity of licorice (Glycyrrhiza glabra) and tetracycline gel against Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Prevotella intermedia (Pi)- a microbiological invitro study.

The aim of this study was to evaluate and compare the antibacterial efficacy of licorice gel and tetracycline gel against Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia. An indigenously prepared 50 μL licorice and tetracycline gel was subjected to antibacterial sensitivity test (thrice) against Aa, Pg, Pi by agar well diffusion method using Brain Heart Infusion media. Colonies of Aa, Pg, Pi was transferred into broth and incubated at 37 °C for 24 h and diameter of inhibition zone was measured. The drug release profile of licorice gel at six regular intervals was higher when compared to tetracycline. MIC of licorice gel (50 μg/mL) against Aa (14 mg), Pg (7 mg), Pi (7 mg) respectively. The diameter of inhibition zone of licorice gel was significant against Aa when compared to tetracycline gel. However, tetracycline gel exhibited significant diameter of inhibition zone against Pg and Pi when compared to licorice gel. There was a statistical significance difference between licorice and tetracycline gel against Aa (p=0.043*), Pg (p=0.037*), Pi (p=0.046*) while assessing antibacterial sensitivity test. Licorice gel has anti-inflammatory and anti-microbial properties which can act against periodontal pathogens and can be considered in treating periodontal disease at low concentrations. Therefore, it can be used as an adjunctive local drug delivery agent to non-surgical periodontal therapy (NSPT) in treating periodontal disease.

Unjustified use of amber necklaces for teething symptoms alleviation: Succinic acid release underperforms compared with natural skin bacteria production.

There is limited evidence of succinic acid release from amber necklace that justifies its biological plausibility. This study aimed to evaluate the release of succinic acid from Baltic amber beads in the presence of Staphylococcus epidermidis. The Baltic amber beads from the necklace were stratified according to their weight (average 0.05 g ± 0.067). Subsequently, the beads (n = 8) were submerged in 0.9% buffered saline (Control) or brain-heart infusion culture medium in the presence of a commercial strain of S. epidermidis, a resident skin bacterium incubated at 37°C for 24 h or 7 days. The samples were centrifuged, and the supernatants were analyzed by 1H Nuclear Magnetic Resonance. Multivariate analyses were adopted using the sparse partial least squares discriminant analysis method (p < .05). The group incubated with saline solution showed small release of succinic acid only after 7 days. In the groups with S. epidermidis, the release of succinic acid was observed in the both presence and absence of amber beads, indicating that succinic acid is a product released by bacteria. It was found that amber beads do not exhibit the ability to release expressive succinic acid, especially in a short period of time, which does not justify their use in infants. The most production of succinic acid is tributed to S. epidermidis.

Comparative Gene Expression Analysis of Salmonella Typhimurium DT104 in Ground Chicken Extract and Brain Heart Infusion Broth.

Salmonella enterica Typhimurium DT104 (S. Typhimurium DT104) is an important foodborne pathogen that is associated with poultry and poultry products. Currently, there is very little information on the underlying molecular mechanisms that allow DT104 to survive and propagate in poultry meat and the poultry processing environment. The current study assessed the global gene expression of DT104 in ground chicken extract (GCE) compared to brain heart infusion (BHI) medium using RNA-Seq technology. DT104 was grown to the early stationary phase (ESP), inoculated into GCE or BHI, and then re-grown to the log phase before RNA was extracted and transcripts were quantified by RNA-Seq. Gene expression for DT104 grown in GCE was then compared to that of DT104 grown in BHI for samples grown to the ESP. Growth in GCE resulted in the up-regulated expression of genes related to translation, carnitine metabolism (23-283-fold change), and cobalamin (vitamin B12) biosynthesis (14-fold change). In particular, the presence of carnitine in chicken meat, and thus, in GCE, which lacks carbohydrates, may allow Salmonella to utilize this compound as a carbon and nitrogen source. This study demonstrates that RNA-Seq data can provide a comprehensive analysis of DT104 gene expression in a food model for poultry products. This study also provides additional evidence for the importance of metabolic adaptation in the ability of S. enterica to successfully adapt to and occupy niches outside of its host and provides potential targets that could be used to develop intervention strategies to control Salmonella in poultry.

Bacteriological profile of bloodstream infections in pediatric age group in a tertiary care centre, Solapur

Bloodstream infections (BSI) due to multidrug-resistant organisms from paediatric setup have become increasingly common. BSI can be transient and be rapidly cleared out by the host defence mechanism or be associated with high morbidity and mortality if it becomes persistent.Blood samples were collected from 1112 children within a 1-year study period (July 2022 to June 2023) which included all children admitted with complaint of fever and suspected of having sepsis in Paediatric department of Shri Chhatrapati Shivaji Maharaj Sarvopchar Rugnalaya (SCSMSR), Solapur. Blood volume was collected depending upon age and body weight of the patient with aseptic precautions and inoculated in Brain Heart Infusion broth (BHI) which was incubated at 37°C for 7 days. Subcultures were made on blood agar and MacConkey agar plates. Organisms were identified by biochemical reactions and antibiotic susceptibility test of the isolates were performed by disk diffusion. Out of 1112 suspected cases, 175 (15.74%) were culture positive. (27.43%) was the most common isolate followed by (16.57%) Most common Gram positive isolate was (11.43%) followed by (6.86%). Total Multidrug resistant (MDR) isolates in Gram negative and Gram positive were 50.35% and 31.25% respectively.High rates of antibiotic resistance are observed in both gram positive and gram negative organisms. Thus, there is an urgent need for proper implementation of antibiotic stewardship programme and infection prevention and control measures.

Detection of Pseudomonas aeruginosa pus wound isolate using a polymerase chain reaction targeting 16S rRNA and gyrB genes: A case from Indonesia.

Infectious wounds on the skin surface are easily colonized by bacteria from pyogenic group that manifest as inflammation, such as Pseudomonas aeruginosa. P. aeruginosa is a Gram-negative bacterium and an opportunistic pathogen known for causing invasive state in critically ill and immunocompromised patients. The aim of this study was to detect the 16S rRNA and gyrB genes in P. aeruginosa using polymerase chain reaction (PCR) method. The sample in this study was pus isolate from a 5-year-old boy with leg wounds. The bacteria were isolated on brain heart infusion broth (BHIB) media and identified with molecular identification. Sequencing and BLAST analysis were carried out to determine the similarity of gene identity by comparing sample sequence with other isolate sequences on the Gene Bank. The results of molecular identification showed amplification DNA band of around 934 base pairs (bp) for 16S rRNA and 225 bp for gyrB gene. The BLAST program demonstrated that the sample had 99.89% similarity with P. aeruginosa strain XC4 (accession code ON795960.1) for the 16S rRNA gene. Meanwhile, the gyrB gene exhibited 99.10% similarity with the P. aeruginosa strain PSA-1.2 (accession code KP172300.1).

Evaluation of Simultaneous Growth of Escherichia coli O157:H7, Salmonella spp., and Listeria monocytogenes in Ground Beef Samples in Different Growth Media.

Several multiplex approaches for the simultaneous detection of pathogens in food have been developed in recent years, but the use of a single enrichment medium remains a problem. In this study, six enrichment broths (five non-selective media, tryptic soy broth (TSB), brain heart infusion broth (BHI), buffered peptone water (BPW), universal pre-enrichment broth (UPB), no. 17 broth, and a selective, Salmonella Escherichia Listeria broth (SEL)), were studied for the simultaneous detection of E. coli O157:H7, Salmonella spp., and L. monocytogenes, to validate the suitable enrichment broth to be used for the detection methods. Different ratios of E. coli O157:H7, Salmonella spp., and L. monocytogenes were used. Almost all non-selective broths evaluated in this study showed similar growth parameters and profiles among each other. The only selective enrichment broth under analysis (SEL) showed distinct growth features compared to the non-selective media, allowing for a slower but balanced growth of the three pathogens, which could be beneficial in preventing the overgrowth of fast-growing bacteria. In addition, when tested in ground beef samples, SEL broth seems to be the most distinctive medium with a balanced growth pattern observed for the three pathogens. Overall, this study is intended to provide the basis for the selection of suitable enrichment broths according to the technology detection to be used, the desired time of enrichment, and the expected balanced concentration of pathogens.

A comparative analysis of the antimicrobial efficacy of different concentrations of silver nanoparticles and chlorhexidine against Enterococcus faecalis - In vitro study

Introduction: Root canal irrigants combat endodontic microbial flora, effectively targeting resilient microbes like Enterococcus faecalis, which persist despite treatment. Chlorhexidine (CHX), as an irrigant, boasts broad-spectrum antibacterial activity, notable substantivity in dentine, and favorable biocompatibility. In the realm of nanotechnology, the use of silver nanoparticle (AgNP) solutions appears promising, given their strong antibacterial and antimicrobial properties. Objective: The objective of the study was to compare the antimicrobial effectiveness of varying concentrations (1%, 0.75%, and 0.5%) of AgNPs and 2% CHX against E. faecalis. Materials and Methods: Four irrigant solutions, including 1%, 0.75%, and 0.5% AgNPs and 2% CHX with gentamicin as the control, will be assessed. The ATCC 29212 strain of E. faecalis will be cultivated at 37°C on brain–heart infusion Broth plates. After 48 h, the bacterial population will be quantified by counting colony-forming units on agar plates. Each irrigant will be applied to the plates, and the resulting bacterial inhibition zone will be measured. Results: Our study demonstrates the antimicrobial effects of 1%, 0.75%, and 0.5% AgNPs and 2% CHX against E. faecalis. While 2% CHX exhibited superior activity, AgNPs at various concentrations also displayed inhibitory effects against E. faecalis. Conclusion: In conclusion, this study highlights the antimicrobial properties of 1%, 0.75%, and 0.5% AgNPs and 2% CHX against E. faecalis. The results indicate that 2% CHX exhibits superior activity, while AgNPs at various concentrations also demonstrate inhibitory zones against E. faecalis.

Molecularly imprinted nanogels as synthetic recognition materials for the ultrasensitive detection of periodontal disease biomarkers.

Periodontal disease affects supporting dental structures and ranks among one of the top most expensive conditions to treat in the world. Moreover, in recent years, the disease has also been linked to cardiovascular and Alzheimer's diseases. At present, there is a serious lack of accurate diagnostic tools to identify people at severe risk of periodontal disease progression. Porphyromonas gingivalis is often considered one of the most contributing factors towards disease progression. It produces the Arg- and Lys-specific proteases Rgp and Kgp, respectively. Within this work, a short epitope sequence of these proteases is immobilised onto a magnetic nanoparticle platform. These are then used as a template to produce high-affinity, selective molecularly imprinted nanogels, using the common monomers N-tert-butylacrylamide (TBAM), N-isopropyl acrylamide (NIPAM), and N-(3-aminopropyl) methacrylamide hydrochloride (APMA). N,N-Methylene bis(acrylamide) (BIS) was used as a crosslinking monomer to form the interconnected polymeric network. The produced nanogels were immobilised onto a planar gold surface and characterised using the optical technique of surface plasmon resonance. They showed high selectivity and affinity towards their template, with affinity constants of 79.4 and 89.7nM for the Rgp and Kgp epitope nanogels, respectively. From their calibration curves, thetheoretical limit of detection was determined to be 1.27nM for the Rgp nanogels and 2.00nM for the Kgp nanogels. Furthermore, they also showed excellent selectivity against bacterial culture supernatants E8 (Rgp knockout), K1A (Kgp knockout), and W50-d (wild-type) strains in complex medium of brain heart infusion (BHI).

Surgical Site Infections in Gastrointestinal Surgeries: Estimation of Prevalence, Risk Factors and Bacteriological Profile.

Surgical site infections (SSIs) are one of the leading causes of operation-related adverse effects.To create an effective hospital infection program, information about a local pattern is essential. The ever-changing pattern of infections and inappropriate use of antibiotics has predisposed to the development of drug-resistant strains and has made the management of SSIs arduous. The purpose of this study is to estimate prevalence and identify risk factors and commonest organisms associated with SSIs. In this analytical cross-sectional study, the relationship between various risk factors and the development of SSIswas evaluated in patients undergoing elective surgery and staying at least seven days postoperatively in the Department of Surgical Gastroenterology and Liver transplant for a study duration of two months. Diagnosis of SSIs was based on modified CDC criteria. Wound pus was followed by blood collection in suspected secondary septicemia. MacConkey and blood agar were used to culture pus; brain heart infusion broth was used for blood samples. Antimicrobial susceptibility testing was carried out using Mueller-Hinton agar by the Kirby-Bauermethod. Twelve out of 50 had developed postsurgical wound infections where Gram-negative organisms prevailed over Gram-positive ones. The associated risk factors identified in this study are age, BMI, wound class, American Society of Anesthesiologists (ASA) score, preprocedural WBC count >10,000, and the duration of surgery. Escherichia coli is the causative microbe for the majority of infections (35.7%). Gram-negative bacteria isolated in this study were extended-spectrum β-lactamase (ESBL) producers. Multidrug-resistant organisms were predominant. Conclusion: The present study identified an SSI rate of 24% in gastrointestinal surgeries. The sensitivity and resistance pattern of the organisms isolated will help in measures to be taken to devise a proper and effective current hospital antibiotic prophylaxis policy.

Global biochemical profiling of fast-growing Antarctic bacteria isolated from meltwater ponds by high-throughput FTIR spectroscopy.

Fourier transform infrared (FTIR) spectroscopy is a biophysical technique used for non-destructive biochemical profiling of biological samples. It can provide comprehensive information about the total cellular biochemical profile of microbial cells. In this study, FTIR spectroscopy was used to perform biochemical characterization of twenty-nine bacterial strains isolated from the Antarctic meltwater ponds. The bacteria were grown on two forms of brain heart infusion (BHI) medium: agar at six different temperatures (4, 10, 18, 25, 30, and 37°C) and on broth at 18°C. Multivariate data analysis approaches such as principal component analysis (PCA) and correlation analysis were used to study the difference in biochemical profiles induced by the cultivation conditions. The observed results indicated a strong correlation between FTIR spectra and the phylogenetic relationships among the studied bacteria. The most accurate taxonomy-aligned clustering was achieved with bacteria cultivated on agar. Cultivation on two forms of BHI medium provided biochemically different bacterial biomass. The impact of temperature on the total cellular biochemical profile of the studied bacteria was species-specific, however, similarly for all bacteria, lipid spectral region was the least affected while polysaccharide region was the most affected by different temperatures. The biggest temperature-triggered changes of the cell chemistry were detected for bacteria with a wide temperature tolerance such Pseudomonas lundensis strains and Acinetobacter lwoffii BIM B-1558.

Bacterial contamination in contact lens training area in private optical clinics

BackgroundContamination in the contact lens training area could be due to bacteria, which can lead to the major consequence of ocular infections. We aimed to investigate the contamination caused by bacteria in the contact lens training area in private optical clinics of the Udupi district, India.MethodsA cross-sectional study evaluated the swabs from the contact lens container, contact lens solution tip, washing area and lens fitting area for bacterial contamination. Twenty swabs collected from different areas of five optical clinics were inoculated in Brain heart infusion broth (BHIB). The broth was streaked in MacConkey and Blood agar and incubated at standard conditions for the growth of bacteria. All isolates were identified using conventional culture methods, and Gram staining was performed.ResultsTwenty samples (contact lens case, n = 5; contact lens solution tip, n = 5; washing area, n = 5; cleaning towel, n = 5) from private optical clinics were recruited for the study. Bacterial growth was indicated in which lactose fermentation was seen at (15%), non-lactose fermentation at (35%), and no bacterial growth at (50%) in MacConkey agar. Partial or alpha-hemolytic (α hemolysis) was seen in (5%), complete or beta-hemolytic (β hemolysis) was seen in (40%), no hemolysis or gamma hemolysis (ϫ haemolysis), was seen in (30%), no growth was seen in (25%) on blood agar. Gram-positive cocci (45%), Gram-negative bacilli (20%), and no increase in (35%) were observed in MacConkey agar and Blood agar. Bacterial species were not identified in this study.ConclusionContamination was found in lenses, solution tips, washing areas, and cleaning towels which might lead to ocular infections. Perception should be given to those responsible for fitting lenses.

Impact of pH and High-Pressure Pasteurization on the Germination and Development of Clostridium perfringens Spores under Hyperbaric Storage versus Refrigeration.

This study aimed to evaluate hyperbaric storage at room temperature (75-200 MPa, 30 days, 18-23 °C, HS/RT) on Clostridium perfringens spores in brain-heart infusion broth (BHI-broth) at pH 4.50, 6.00, and 7.50 and coconut water (pH 5.40). Both matrices were also pasteurized by high pressure processing (600 MPa, 3 min, 17 °C, HPP) to simulate commercial pasteurization followed by HS, in comparison with refrigeration (5 °C, RF). The results showed that, at AP/RT, spores' development occurred, except at pH 4.50 in BHI-broth, while for RF, no changes occurred along storage. Under HS, at pH 4.50, neither spore development nor inactivation occurred, while at pH 6.00/7.50, inactivation occurred (≈2.0 and 1.0 logs at 200 MPa, respectively). Coconut water at AP/RT faced an increase of 1.6 logs of C. perfringens spores after 15 days, while for RF, no spore development occurred, while the inactivation of spores under HS happened (≈3 logs at 200 MPa). HPP prior to HS seems to promote a subsequent inactivation of C. perfringens spores in BHI-broth at pH 4.50, which is less evident for other pHs. For HPP coconut water, the inactivation levels under HS were lower (≈2.0 logs at 200 MPa). The Weibull model well described the inactivation pattern observed. These results suggest that HS/RT can be simultaneously used as a tool to avoid C. perfringens spores' development, as well as for its inactivation, without the application of high temperatures that are required to inactivate these spores.

Modeling the growth/no growth response of Non-O157 Shiga toxin-producing Escherichia coli to temperature, pH and water activity

The objective of this study was to model the effect of temperature, pH and water activity (aw) on the growth/no growth response of non-O157 Shiga toxin-producing E. coli (STEC). A cocktail of six-serogroup STEC was inoculated into brain heart infusion broth (BHI) with 48 combinations of different pH and aw, and the inoculated medium was incubated at one of ten temperatures. After 62 days of incubation, growth was determined by turbidity and plating on tryptic soy agar. Binary data (0 [no growth] or 1 [growth]) were fitted into a nonlinear logistic regression and the parameters were estimated. The model was validated with independently produced data from seven serogroups of non-O157 STEC, a cocktail of E. coli O157:H7, and two panels of six-serogroup of STEC. The non-O157 STEC did not grow at temperatures ≤6 °C and ≥47 °C, and the highest tolerance to pH and aw occurred at 25 °C. Although slight difference in the growth/no growth response was observed among different groups of STEC, the developed model can be applied to all the STECs with an average concordance of 92.3%. This work provides valuable insight into the growth/no-growth response of STEC under various environmental conditions.