Levels Of Gram-negative Bacteria Research Articles

Intraosseous regional prophylactic antibiotics decrease the risk of infection in total knee arthroplasty compared with intravenous antibiotics: a systematic review and meta-analysis.

Surgical site infection (SSI) is a rare and serious complication of total knee arthroplasty (TKA), which causes a poor prognosis for patients. The purpose of this study was to explore the effect of intraosseous (IO) antibiotics in preventing infection and complications after TKA compared with intravenous (IV) antibiotics and to provide a certain theoretical basis for clinical treatment. The review process was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched the PubMed, Embase, Ovid, Web of Science, and the Cochrane Central Register of Controlled Trials databases about trials on IO antibiotics (into the proximal tibia before skin incision) to prevent infections in TKA from the respective inception dates to September 30, 2022. The infection occurred within 3 months after surgery. Both researchers individually screened the studies in accordance with the inclusion and exclusion criteria, performed the literature quality evaluation and data extraction, and used Stata 17 software for data analysis. Five studies that enrolled 3801 patients were included in this meta-analysis. The results showed that IO antibiotics were effective in reducing the incidence of SSI (OR: 0.25, P = 0.001) and periprosthetic joint infections (OR: 0.16, P = 0.004) relative to IV. Moreover, the percentage of infection due to Gram-positive bacteria (OR: 0.18, P = 0.025) was reduced in the IO group compared with that in IV group, but Gram-negative bacteria levels were not significantly reduced (P = 0.14). There was no difference between the two groups for other systemic adverse effects of the drug. IO antibiotics in TKA are safe and effective alternatives to IV antibiotics. Large randomized clinical studies comparing infection rates and related complications with IO and IV antibiotics are required.

Effect of sigma E on carbapenem resistance in OXA-48-producing Klebsiella pneumoniae.

Resistance levels of Gram-negative bacteria producing OXA-48 carbapenemase can vary greatly and some of them can even be categorized as susceptible to imipenem and meropenem according to EUCAST breakpoints. This study aimed to reveal resistance mechanisms leading to varying levels of resistance to carbapenems in Klebsiella pneumoniae with blaOXA-48 submitted to the German National Reference Centre for MDR Gram-negative bacteria. Meropenem-susceptible clinical blaOXA-48-bearing K. pneumoniae isolates were put under gradually increasing selective pressure of meropenem. Clinical isolates and spontaneous meropenem-resistant mutants were whole-genome sequenced with Illumina and Oxford Nanopore Technology. Identified mutations apart from porin mutations were genetically constructed in the original clinical isolates using CRISPR/Cas. Clinical isolates and mutants were analysed for MICs, growth rates and expression of porins on mRNA and protein levels. Mutations associated with meropenem resistance were predominantly found in ompK36, but in some cases ompK36 was unaffected. In two mutants, ISs within the rpoE (sigma factor E; σE) operon were detected, directly in or upstream of rseA. These IS1R elements were then inserted into the same position of the susceptible clinical isolates using CRISPR/Cas. CRISPR-rseA-rseB-rseC mutants showed higher resistance levels to carbapenems and cephalosporins, reduced growth rates and reduced expression of major porins OmpK36 and OmpK35 in quantitative RT-PCR and SDS-PAGE. Enhanced synthesis of σE leads to increased resistance to cephalosporins and carbapenems in clinical K. pneumoniae isolates. This effect could be based upon remodelling of expression patterns of outer membrane proteins. The up-regulated σE stress response also leads to a significant reduction in growth rates.

Evaluation of microbal colonization of the oral cavity in patients with intolerance to materials of fixed dentures.

To improve prevention and treatment of intolerance to fixed denture materials by studying the impact of status of microbial contamination of the oral cavity on the pathogenesis of its development. The clinical study was performed in 62 patients, 22 of them came to the clinic for prosthetics and with clinical symptoms of intolerance to fixed dentures. The comparison group consisted of patients without clinical manifestations of intolerance. Healthy individuals without prosthesis were used as a control group. The results of clinical studies convincingly demonstrate that in the oral mucosa of patients of the main group level of Gram-negative bacteria was higher and that of Gram-positive was lower than in the comparison groups. Indicators in the study group testify to the increase in the total number of microorganisms, especially Gram-negative bacteria and decrease of gram-positive ones. Con­ta­mination with fungi of the genus Candida of the oral mucosa of patients with intolerance to materials of fixed dentures was higher by 67,3% in the main group than in the comparison group.

Effects of dietary mono- and multiprobiotic strains on growth performance, gut bacteria and body composition of Javanese carp (Puntius gonionotus, Bleeker 1850)

This study investigated the effects of dietary mono- and multiprobiotic strains of Enterococcus faecalis, Lactobacillus fermentum and Leuconostoc mesenteroides on growth performance, intestinal bacteria and body composition of Javanese carp (Puntius gonionotus). Moreover, the effect of storage temperature on lactic acid bacteria (LAB) viability in the feed was studied. Compared to the control group, significant (P < 0.05) effect on weight gain, feed conversion ratio, specific growth rate and protein efficiency ratio of probiotic fed Javanese carp was observed. Inclusion of individual LAB strains in the diet resulted in significantly improved growth performances of Javanese carps compared to fish fed a diet supplemented LAB mixture. The inclusion level of E. faecalis at 10 7 colony-forming unit (cfu) g 1 in the diet revealed higher growth performance compared to other treatments. The population levels of LAB in the fish intestine were significantly increased while the levels of Gram-negative bacteria were significantly decreased compared to the control. No significant variations were observed in the chemical composition of the carcass by probiotics. The viability of LAB in feed was higher when stored at 4 °C compared to 25 °C. It is suggested that E. faecalis has a greater potential for use in improving Javanese carp culture outcomes.

Subgingival Bacterial Burden in Relation to Clinical and Radiographic Periodontal Parameters

This cross-sectional study characterizes the association between subgingival bacterial profile and periodontal parameters in patients assigned to coronary angiography because of cardiologic problems, which may affect the oral microbiota. Pooled subgingival bacterial samples were collected from 477 dentate individuals during the oral examinations, along with periodontal probing depth (PD) and assessments of bleeding on probing (BOP) and radiographic alveolar bone loss (ABL). The checkerboard DNA-DNA hybridization assay was used to determine the levels of 29 oral bacteria, which were divided into three bacterial complexes. All bacterial combinations from the etiologic bacterial group and each species from the red complex were significantly associated (P <0.001) with grade of ABL. The prevalence of the etiologic bacterial group and the level of each species were also associated strongly with the proportion of sites with PD 4 to 5 mm and ≥ 6 mm, BOP, and ABL, except Aggregatibacter actinomycetemcomitans. Levels of Gram-negative oral bacteria correlated significantly with those of Gram-positive species (r = 0.840, P <0.001). In multiple logistic regression analysis, the prevalence of the etiologic bacterial group, levels of Gram-negative bacteria and Treponema denticola, and the prevalence of Porphyromonas gingivalis and T. denticola associated significantly with ABL, whereas other bacterial complexes and levels of Gram-positive species did not. Although levels of Gram-negative and -positive species paralleled periodontal parameters, only the species considered etiologic were associated with ABL.

Airborne bacteria and fungi associated with waste-handling work

Municipal workers handling household waste are potentially exposed to a variety of toxic and pathogenic substances, in particular airborne bacteria, gram-negative bacteria (GNB), and fungi. However, relatively little is known about the conditions under which exposure is facilitated. This study assessed levels of airborne bacteria, GNB, and fungi, and examined these in relation to the type of waste-handling activity (collection, transfer, transport, and sorting at the waste preprocessing plant), as well as a variety of other environmental and occupational factors. Airborne microorganisms were sampled using an Andersen single-stage sampler equipped with agar plates containing the appropriate nutritional medium and then cultured to determine airborne levels. Samples were taken during collection, transfer, transport, and sorting of household waste. Multiple regression analysis was used to identify environmental and occupational factors that significantly affect airborne microorganism levels during waste-handling activities. The "type of waste-handling activity" was the only factor that significantly affected airborne levels of bacteria and GNB, accounting for 38% (P = 0.029) and 50% (P = 0.0002) of the variation observed in bacteria and GNB levels, respectively. In terms of fungi, the type of waste-handling activity (R2 = 0.76) and whether collection had also occurred on the day prior to sampling (P < 0.0001, R2 = 0.78) explained most of the observed variation. Given that the type of waste-handling activity was significantly correlated with levels of bacteria, GNB, and fungi, we suggest that various engineering, administrative, and regulatory measures should be considered to reduce the occupational exposure to airborne microorganisms in the waste-handling industry.

Quantitative and qualitative microbial analysis of raw milk reveals substantial diversity influenced by herd management practices

The quantitative (n = 260) and qualitative (n = 24) microbial compositions of raw milk samples were assessed using culture analyses and a molecular inventory based on the rDNA sequences of 1697 isolates. A statistical analysis was also performed to correlate farm practices with the microbial populations present in the milk samples. Ripening bacteria and Pseudomonas were the dominant groups. Milk samples were distinguishable by the different proportions of their microbial groups, which varied among producers. Individual practices influenced the levels of technologically important microorganisms, for example, pre-dipping of teats reduced levels of lactococci. Standard plate counts correlated with the levels of Gram-negative bacteria, Pseudomonas, lactococci and ripening bacteria, depending on the milking season. Lactic acid bacteria and yeasts, which were poorly represented, nevertheless seemed to constitute a resilient basal flora. Qualitative species diversity was considerable, with more than 100 bacterial species identified, dominated by Gram-positive bacteria, notably staphylococci and Corynebacterium.

오리 사육장의 공기 중 부유 미생물 및 내독소 노출 농도

The aim of this study was to determine the concentrations of air-borne microorganisms (bacteria, fungi, gram negative bacteria (GNB), endotoxins, and respirable suspended particles (RSPs), and their correlation with environmental parameters (temperature, humidity, and carbon dioxide levels) in duck houses. The mean concentrations of bacteria, fungi, and GNB were very high (> <TEX>$10^6\;CFU/m^3$</TEX>), and endotoxin levels exceeded <TEX>$10^3\;EU/m^3$</TEX>. Among the various work stages, in the task of receiving ducks, bacteria were <TEX>$6.2{\times}10^6;CFU/m^3$</TEX>, and GNB were <TEX>$5.4{\times}10^6\;CFU/m^3$</TEX>, while RSPs levels were <TEX>$397.6\;{\mu}g/m^3$</TEX> and endotoxin levels were <TEX>$47.2{\times}10^3\;EU/m^3$</TEX> in the task of dividing the ducks, and fungi were <TEX>$4.9{\times}10^6\;CFU/m^3$</TEX> in the task of shipping the ducks. The concentrations of RSPs and endotoxins were significantly higher in tasks involving greater movement of ducks in the house, relative to tasks involving little movement of ducks (p<0.05). Further, with progression in growth of the ducks, the concentrations of bacteria, GNB, endotoxins, and RSPs were significantly increased. There was significant correlation between levels of GNB with bacteria (r=0.75) and fungi (r=0.86), endotoxins with RSPs (r=0.75), bacteria with fungi (r=0.39), and carbon dioxide with RSPs (r=0.38), bacteria (r=0.33), and endotoxins (r=0.31). These results suggest considerable respiratory hazard for farmers in these environments.

No causal link between obesity and probiotics

1that probiotics increase the risk of obesity. The impact of probiotics in farm animals has been shown to include: an increase in size and weight but not in fat mass 2,3 ; a reduction in fat mass in farm animals that are gaining weight 4,5 ; or no impact on growth 6 . In the livestock industry, probiotics are used to promote growth and lean mass, not adiposity. These observations are consistent with weight gain resulting from improved gut function and resistance to infection rather than from a metabolic imbalance that causes obesity. No human study cited by Raoult showed a statistically significant increase in weight gain for subjects who were given probiot ics compared to those who were given a placebo 7,8 . In spite of the widespread use of probiotics in modern and traditional diets, there is no evidence that the consumption of probiotics leads to weight gain in healthy people. Most probiotics are delivered as dairy products, and in the USA, where levels of obesity are high, consumption of probiotic yogurt (4 kg per person per year) is substantially lower than that in countries such as France, Finland and Japan, where obesity rates are low. The data showing an association between obesity and both a reduction in the levels of Gram-negative bacteria and an increase in the levels of Firmicutes in the gut are mainly based on statistical correlations that cannot distinguish between cause and consequence. Furthemore, these data have been partly con tradicted by numerous other studies, includ ing that of Turnbaugh et al. 9 , which revealed a higher proportion of Actinobacteria and a lower proportion of Bacteroidetes among obese subjects but no significant difference in Firmicute levels. In other studies, comparisons of microbiota using real-time PCR revealed a higher Bacteroidetes/Firmicutes ratio among overweight and obese subjects than among lean ones 10 . At least one study has shown a resultant decrease in body weight and fat mass in obese individuals taking prebiotics 11 . The consumption of probiotics does not lead to any sustained compositional change in the gut microbiota, and there is no suggestion from a multitude of human studies that weight gain is a side effect of probiotic consumption. Probiotic-induced weight gain in ill or undernourished sub jects, which might result from improved gut function, is not an adverse outcome. Unfortunately, Raoult confuses probiotics (live microbes) and prebiotics (selectively fermented substrates for beneficial colonizing microbes) and is inaccurate with regard to the microbio logical identity of different probiotics. Strains of the Bifidobacterium genus, commonly used as probiotics and indicted by Raoult as contributors to increased levels of Firmicutes, are in fact members of the phylum Actinobacteria. Furthermore, there are important strain-to-strain

Efficacy of FIT Produce Wash and Chlorine Dioxide on Pathogen Control in Fresh Potatoes

A commercial fresh pack potato operation was used as a model to evaluate FIT fruit and vegetable wash effectiveness in reducing levels of microorganisms on potatoes and in flume water. Fresh potatoes were washed in flume water with or without FIT, or treated with a spray bar utilizing either FIT, 9 ppm chlorine dioxide (CIO2), or a water control. Both flume treatments were also evaluated for APC and Gram-negatives. There were no significant differences in reduction of these microorganisms on treated or control potatoes. However, levels of Gram-negative bacteria in FIT-amended flume water were reduced by 5.95 log CFU/g, and the APC was reduced by 1.43 log CFU/g. To validate plant trial findings, this test was repeated using solutions of sterile potato flume water from the fresh pack operation, containing a typical level of dissolved and suspended solids. Treatment solutions prepared with flume water or deionized water containing FIT, 9 ppm CIO2, or a water control were inoculated with E. coli O157:H7, Salmonella Typhimurium, or Pectobacterium carotovorumssp. carotovorum. FIT and ClO2 prepared with deionized water reduced levels of microorganisms by >6.1 to 6.6 log CFU/g to below the detection limit. FIT prepared with flume water reduced levels of all organisms by >6.0 to 6.4 log CFU/g to below the detection limit, whereas ClO2 prepared from flume water reduced bacterial levels of all organisms by only 0.7 to 1.4 log CFU/g. Neither FIT nor ClO2 was particularly efficacious against E. coli O157:H7, S. Typhimurium, APC, yeasts, or molds on potato surfaces.

Effect of an Electrostatic Space Charge System on Airborne Dust and Subsequent Potential Transmission of Microorganisms to Broiler Breeder Pullets by Airborne Dust

High levels of dust and microorganisms are known to be associated with animal confinement rearing facilities. Many of the microorganisms are carried by dust particles, thus providing an excellent vector for horizontal disease transmission between birds. Two environmentally controlled rooms containing female broiler breeder pullets (n = 300) were used to evaluate the effectiveness of an electrostatic space charge system (ESCS) in reducing airborne dust and gram-negative bacteria levels over an 8-wk period (starting when the birds were 10 wk old). The ESCS was used to evaluate the effectiveness of reducing airborne microorganism levels by charging airborne dust particles and causing the particles to be attracted to grounded surfaces (i.e., walls, floor, equipment). The use of the ESCS resulted in a 64% mean reduction in gram-negative bacteria. Airborne dust levels were reduced an average of 37% over a 1-wk period in the experimental room compared with the control room on the basis of samples taken every 10 min. The reductions of airborne dust and bacteria in this study are comparable with earlier results obtained with the ESCS in commercial hatching cabinets and experimental caged layer rooms, suggesting the system could also be applied to other types of enclosed animal housing.

Exposure to biohazards in wood dust: bacteria, fungi, endotoxins, and (1-->3)-beta-D-glucans.

Personal exposure to fungi, bacteria, endotoxin, and (1-->3)-beta-D-glucan was determined at different woodworking sites--logging sites, sawmills, woodchipping sites, and joineries. Exposure levels to fungi at logging sites and sawmills were in the range of 10(3)-10(4) cfu/m3, at the woodchipping mill, 10(3)-10(5) cfu/m3, and at joineries, 10(2)-10(4) cfu/m3. Although mean endotoxin levels were lower than the suggested threshold value of 20 ng/m3, some personal exposures at sawmills and a joinery exceeded the standard. The geometric mean personal (1-->3)-beta-D-glucan exposure level at the woodchipping mill was 2.32 ng/m3, at sawmills, 1.37 ng/m3, at logging sites, 2.02 ng/m3, and at joineries, 0.43 ng/m3. Highly significant associations were found between mean personal inhalable endotoxin exposures and Gram-negative bacteria levels (p < 0.0001), and mean personal inhalable (1-->3)-beta-D-glucan exposures and fungi levels (p = 0.0003). The prevalence of cough, phlegm, chronic bronchitis, nasal symptoms, frequent headaches, and eye and throat irritations was significantly higher among woodworkers than controls. Dose-response relationships were found between personal exposures and work-related symptoms among joinery workers and sawmill and chip mill workers.

Restriction of bacterial growth under commercial catheter dressings

The effect on the normal cutaneous flora after iodine and alcohol disinfection of the skin of three commercially available moisture-permeable polyurethane dressings was compared with that of a gauze-and-tape dressing. Dressings also were evaluated clinically for membrane adhesion and skin erythema, pruritis, hyperpigmentation, vesiculitis, and tenderness. Each of 50 healthy volunteers and 49 long-term inpatients, 25 of whom were receiving antibiotic therapy, received simultaneously on their volar forearm patches of Op-Site, Tegaderm, Uniflex, and gauze dressings. Controls consisted of one exposed skin site and one covered with moisture-retaining vinylidene film (Saran Wrap). Although after 3 days of adhesion, commercial dressings prevented indigenous flora from returning to normal population densities, no significant quantitative differences were found between them and the gauze-and-tape dressing. Generally, all clinical dressings maintained normal flora at one tenth the population of the uncovered site; the Saran Wrap control supported 100-fold more bacteria than the exposed site. No difference were discovered in the levels of gram-negative bacteria, or among-patient groups and between patients and healthy subjects, except for the lower incidence of erythema and itching among patients compared with healthy subjects.

Changes in Gram-Negative Bacteria and Endotoxin in Stored Bales of Lint

Cotton subjected to several harvesting and ginning treatments was stored in a warehouse for six months. The bales of lint were sampled during ginning and the storage period and the samples analyzed for gram-negative bacteria and endotoxin content. Levels of gram-negative bacteria decreased during the storage period; however, no trends were observed in the endotoxin levels. Gram-negative bacteria levels were highest for the bales of lint that contained the highest levels of moisture and foreign matter.

Levels of gram-negative bacteria, Aspergillus fumigatus, dust, and endotoxin at compost plants.

Airborne gram-negative bacteria, endotoxins, dust, and Aspergillus fumigatus were measured in four compost plants in Sweden. At sites where material was processed, the number of airborne A. fumigatus exceeded 10(6)/m3, whereas the number of gram-negative bacteria was usually lower. Dust levels were moderate, and endotoxin levels were well below 0.5 micrograms/m3. Medical studies to evaluate the effects of this type of microbial exposure are recommended.

Environment influences levels of gram negative bacteria and endotoxin on cotton bracts

Environment influences levels of gram negative bacteria and endotoxin on cotton bracts

Environment influences levels of gram negative bacteria and endotoxin on cotton bracts

Bracts were collected at two geographical locations to determine if biological and physical changes occur in these plant parts as they mature and senesce in the cotton field during late summer and throughout the autumn. The mass median diameter of bracts subjected to laboratory abrasion tests decreases after the first killing freeze. A dramatic increase in the content of gram negative bacteria (GNB) and endotoxin occurs in whole bracts collected after the first killing freeze. The level of GNB and endotoxin in respirable bract dusts increases from 10 to 100 fold after bracts have been frozen in the field.