Majority Of Microorganisms Research Articles

INKT cells participate in the exacerbation of systemic candidal infection

Candida species are one major causal microorganism of hospital acquired bloodstream infections associated with high mortality. Phagocytes like neutrophils in innate immunity and CD4 T cells in acquired immunity have a major role in host defense immune response. It has been recently found that a type of innate-like lymphocyte called NKT cells respond against various organisms but its role in candidal infection remained unknown. Thus, we analyzed the role of NKT cells in the immune response against systemic candidiasis using mice deficient of NKT cells. In vivo studies revealed that invariant NKT cells play a limited role for controlling systemic candidal infection. On the other hand, studies looking at the role of glycolipid-activated NKT cells during candidal infection revealed that candida-infected mice injected with glycolipid had shorter survival period and greater number of fungal colonies in the kidney accompanied with reduced number of neutrophils in the blood and bone marrow. Surprisingly, glycolipid-mediated exacerbation of candidal infection was absent in IFNγ deficient mice. Co-infection of candida with intestinal commensals caused exacerbated infection in which IFNγ played a critical role in impairing fungal elimination. These results suggest that the excessive IFNγ released from candida and bacterial co-infection is a critical factor in worsening candidal infection.

The obesity conundrum – obesity then infection or infection then obesity?

Introduction: Obesity is defined as an excess of body fat, and the fundamental causes are sedentary lifestyles, high-fat and energy-dense diets and the behavioural patterns of communities as a consequence of increased urbanization. Research on obese individuals has shown that they have impaired immune function, which increases their susceptibility to infection. Recently, research has found that various microbes, including gut microbiota, influenza H1N1 virus, adenovirus 36 and Toxoplasma gondii, increase adiposity in humans and that proliferating pre-adipocytes and immune cells share an embryonic origin, which explains the link between obesity and infections. Aim and objectives: The aim of this literature review was to search the scientific literature to ascertain the association between obesity and infectious diseases and to analyse which is a more serious issue – obesity predisposing people to infections or infections leading to obesity. Material and methods: Google, Google Scholar, PubMed and the Journal of Obesity were the research repositories searched for relevant studies using the keywords infectious diseases, microbes and obesity. The research studies were reviewed and the results presented. Results: Through our review we found that the agents that most strongly predisposed people to obesity were adenovirus 36 and 37, T. gondii and Enterobacter, which led to obesity in 30% of adults. A vast majority of micro-organisms, such as influenza H1N1 virus, Candida albicans, Mycobacterium tuberculosis, coxsackievirus and Helicobacter pylori, were found to cause diseases in obese individuals. Conclusion: A review of the current studies does not conclusively prove that infections lead to obesity, with the exception of adenovirus 36; however, it does prove that obese people are prone to infections through an interplay of different mechanisms. Further research is required to establish the eminence of one over the other.

Cesarean Section and Prophylactic Antibiotics

Infectious morbidity remains a leading cause of postoperative complications following caesarean delivery. The major infectious complications of caesarean delivery are fever, wound infection, endometritis and urinary tract infection. Postoperative surgical site infection remains a major source of illness and a less frequent cause of death in the surgical patient. The administration of prophylactic antibiotics with in specific interval has been shown to reduce the burden of surgical site infection, but adherence to proper timing guidelines remains problematic. Judicious use of antibiotics in the hospital through effective antibiotic policy and guideline development is then essential. Pathogenesis of post-cesarean infection: Postoperative endometritis is a polymicrobial infection caused by bacteria normally present in the hosts lower genital tract. The major microorganisms responsible for endometritis are aerobic gram-negative bacilli, principally E.coli; anaerobic gram-negative bacilli, principally Bacteroides species and gardnerella vaginalis; aerobic gram-positive cocci, primarily Group B and Group D streptococci; and anaerobic gram- positive cocci, specifically peptococcus species and peptostreptococcus species. 5

Quality Properties of Ginseng Chicken Porridge Prepared with Individually Gamma Irradiated Raw Materials

This study was to establish irradiation process for serving ginseng chicken porridge to immune-compromised patients. Raw chicken, glutinous rice, ginseng, garlic, dried jujube and carrot were used as raw materials for ginseng chicken porridge. The initial level of microorganisms contaminated in raw materials and their predominant species were determined. The level of microorganism detected in raw chicken and in ginseng were 3.4 Log CFU/g and 4.7 Log CFU/g, respectively. Major predominant microorganisms were Pseudomonas fragi in chicken, Enterobactor faecalis in carrot, and Bacillus subtilis in other materials. Chicken and carrot were excluded from irradiation treatment because ordinary thermal treatment can inactivate the microorganisms contaminated in those materials. Five kGy of gamma ray was the effective sterilizing dose required to inactivate B. subtilis in glutinous rice, garlic and jujube, and 10 kGy in ginseng. Ginseng chicken porridge was prepared with each of raw materials gamma-irradiated with the selected sterilizing doses. Control was ginseng chicken porridge prepared with non-irradiated materials. The growth of microorganisms was not observed in the chicken porridge prepared with irradiated raw materials. Sensory results showed that the score of flavor and off-flavor was slightly lower in ginseng chicken porridge prepared with irradiated raw materials than in control. This was considered to be due to the increase of TBARS values by gamma irradiation. However, there was no significant difference on overall acceptance between the porridge prepared with irradiated raw materials and control. The results showed that the individual gamma irradiation of raw materials can be applied to prepare ginseng chicken porridge as meals for the immunocompromised patients.

Biofilms on the surface of gravels and aquatic plants in rivers and lakes with reusing reclaimed water

Reuse of reclaimed water for the eco-environmental water has become an effective measure to resolve the urban water crisis. However, it still contains large amounts of contaminants which may significantly affect the aquatic ecosystems. Biofilm attached on the surface of multiple matrixes in rivers and lakes is one of the indicators for describing the health of aquatic ecosystem. In this article, we chose eight rivers and lakes as the sampling locations, including three kinds of reclaimed water with different treatment processes and natural water. The morphology, structure and component characteristics of biofilms attached on the surface of aquatic plants and gravels in eight water bodies were evaluated. The results showed that the biofilm on the matrix surface were typical porous media with basic skeleton composed of inorganic particles, microorganisms and algae. The pores were filled with the viscous extracellular polymeric substances (EPS) secreted by microorganisms. The biofilms contained calcite, quartz, illite, alkali feldspar, dolomite, clinochlore, goethite and inorganic salt, and approximately 50 % of these compositions are calcite and quartz. The concentration of EPS was 20.78–500.44 μg/mL, and that of the gravel biofilms was less than that in aquatic plants by 18.1–75.3 %. In these three reclaimed waters, 4–7 kinds of PLFA (phospholipid fatty acid) were detected in aquatic plants biofilms, more than one or two kinds than in gravel biofilms. And the dominant PLFA were i15:0 and 18:0, the total contents of which were, respectively, 74.4, 62.9 and 85.9 % in the three kinds of reclaimed water. All biofilm samples contain major microorganisms such as Pseudomonas, Acinetobacter and Comamonas. This study is aimed to provide some support for assessing the health of river–lake ecosystem with biofilm indicator.

Modified COLD-PCR for detection of minor microorganisms in wine samples during the fermentation

The detection of low-abundant microorganism is difficult when in a sample in which a specific microorganism represents an overwhelming majority using polymerase chain reaction (PCR)-based methods. A modified CO-amplification at Lower Denaturation temperature PCR (mCOLD-PCR) method was developed to detect low-abundant microorganisms using a double-strand RNA probe to inhibit the amplification of the sequence of a major microorganism. Combining the mCOLD-PCR and downstream application (e.g., denaturing gradient gel electrophoresis (DGGE) and next-generation sequencing (NGS)), low-abundant microorganisms were detected more efficiently, even when a specific microorganism represents an overwhelming majority of the sample. We demonstrated that mCOLD-PCR-DGGE enabled us to detect Schizosaccharomyces pombe in a model sample coexisting with 10,000 times as many Saccharomyces cerevisiae. When mCOLD-PCR-DGGE was applied in the microbiota analysis of a fermenting white wine, Candida sp. and Cladosporium sp., which were not detected by conventional PCR, were detected. According to the NGS analysis after mCOLD-PCR of a fermenting red wine, the detection ratio of Saccharomyces was decreased dramatically, and the detection ratios of other microorganisms and the numbers of genera detected were increased compared with the conventional PCR. Thus, the application of mCOLD-PCR will reveal comprehensive microbiota of fermented foods, beverages, and so on.

INVESTIGATION OF EFFECTS OF MEDIA IONS ON THE E.COLI DISINFECTION BY ULTRASOUND

Diminishing water sources and their contamination by pathogenic microorganisms in pariculat set forth the neccessity of application of disinfection processes. Chlorine which has been used for disinfection purposes and disinfection by-products generated bu the reaction of chlorine with organic compounds are known to have adverse effects on human health, therefore the research on alternative disinfection techniques has brought into question. Ultrasound disinfection is among major alternative disinfection technologies. In this study the removal of Eschericia coli that is a major indicator microorganism which is a fecal contamination factor that can be found in water media, was performed in ultrasound reactor. Various frequencies were studied in ultrasound reactor and effects of various media ions (HCO 3 - , NO 3 - , SO 4 -2 ) and hydrogen peroxide and nitrogen gas fed to the system at various flow rates were examined. Optimum microorganism inactivation was attained when the operation frequency of the reactor is 28kHz. The increased concentration of SO 4 -2 and HCO 3 - ions added to the system favored the microorganism inactivation, however the presence of NO 3 - didn't change the inactivation yield of the ultrasound system

Clinical impact of Gram-negative nonfermenters on adults with community-onset bacteremia in the emergency department

To determine clinical predictors and impact of Gram-negative nonfermenters (GNNFs) infections among adults with community-onset bacteremia in the emergency department (ED). Adults with bacteremia visiting the ED from January 2007 to June 2008 were identified retrospectively. Demographic characteristics, underlying illnesses, clinical conditions, bacteremic pathogens, antimicrobial agents, and outcome, were retrieved from chart records. After the exclusion of 261 patients with contamination of blood cultures and 24 patients referred from other hospitals, 518 adults with community-onset bacteremia were eligible; their mean age was 65.1 years, with slight predominance of female (262 patients, 50.6%). Of a total of 565 bacteremic isolates, Escherichia coli (228 isolates, 40.4%) and Klebsiella pneumoniae (100, 17.7%) were the major microorganisms. GNNFs caused bacteremia in 31 (6.0%) patients. A higher proportion of inappropriate antibiotic therapy in the ED (87.1% vs. 26.5%, p < 0.001) and higher 28-day crude mortality rate (19.4% vs. 8.4%, p = 0.05) were observed in bacteremic patients caused by GNNFs than those not caused by GNNFs. In further analysis of Kaplan-Meier survival curve, patients with GNNF bacteremia had a worse outcome than those due to other pathogens (p = 0.04). Multivariate analysis revealed that the independent predictors related to GNNF bacteremia included surgery during previous 4 weeks prior to ED arrival [odds ratio (OR), 10.79; 95% confidence interval (CI), 1.84-63.24; p = 0.01], residents in long-term healthcare facilities (OR, 4.62; 95% CI, 2.08-10.29; p < 0.001), and malignancy (OR, 2.24; 95% CI, 1.10-5.40; p = 0.02). For adults with bacteremia visiting the ED, GNNF is associated with a higher mortality rate and more inappropriate empirical antibiotic therapy in the ED. To allow early administration of empirical antibiotics, several clinical predictors of GNNF infections were identified.

Molecular characterization of Listeria monocytogenes isolated from fresh seafood samples in Iran.

BackgroundAmong all species of Listeria, Listeria monocytogenes (L. monocytogenes) is a major pathogenic microorganism of humans and animals and L. ivanovii is rarely pathogenic for humans. The objective of this study was to isolate and characterize Listeria species and to determine the frequencies of virulence genes in L. monocytogenes serotypes in fresh fish, shrimp, crab and lobster in Isfahan and Shahrekord, Iran.MethodsFrom September 2010 to April 2011, a total of 300 marine food samples were purchased from supermarkets of Isfahan and Shahrekord cities, Iran. All samples were cultured and the positive samples for L. monocytogenes were analyzed for presence of serotypes and virulence genes.ResultsFrom the total 300 samples, 23 (10.45%) fresh fish and 1 (2.5%) shrimp samples were positive for Listeria spp., but there were no positive lobster and crab samples for Listeria species. Only L. monocytogenes was isolated from 17 fish (7.25%) and 1 shrimp (2.5%) samples while L. innocua, L. ivanovii and L. seeligeri only detected in fish samples (2 (0.9%), 3 (1.36%) and 1 (0.45%)), respectively. The plcA, prfA, actA, hlyA and iap virulence genes were detected in all of the 18 L. monocytogenes isolates. Totally, the 4b, 1/2a and 1/2b serotypes were detected in 66.66%, 5.55% and 27.77% bacterial isolates, respectively.ConclusionsConsumption of these sea foods, either raw or undercooked, may contribute to food-borne illness due to L. monocytogenes in Iran. The hygienic quality of sea food products should be observe.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/3422944359800606

한국산 꽃소금과 천일염의 이화학적 특성 및 미생물 분석

한국산 꽃소금의 특성을 알아보기 위하여 국내에서 생산된 꽃소금 3종과 천일염 1종의 이화학적 및 미생물 분석을 실시하였다. 수분함량은 10.54±0.10∼13.82±0.12%, 나머지 조단백, 조지방, 조섬유는 거의 존재하지 않았다. NaCl은 신의도산 꽃소금이 78.81±0.28%, 비금산 꽃소금이 81.67±0.34%, 도초산 꽃소금 84.61±0.21%, 도초산 천일염이 80.82±0.17%로 나타났다. 불용분, 사분은 각각 0.01∼0.05%, 0.01∼0.03%로 낮게 검출되었다. 미네랄 분석은 도초산 꽃소금에서 K과 Mg 함량이 2,975.23 mg/kg, 9,886.72 mg/kg으로 비교적 낮게 나타났다. Ca은 도초산 소금 2종이 945.53 mg/kg, 942.43 mg/kg으로 낮은 함량을 보였다. 중금속 As, Cd, Pb, Hg은 모두 규격 이하로 검출되었다. 소금결정을 관찰한 결과로 천일염과 꽃소금 모두 핵이 중복되어 겹으로 적층된 것을 확인하였으며 크기는 비금산 꽃소금이 0.067×0.067 mm로 가장 작고 도초산 천일염이 0.112×0.124 mm로 꽃소금에 비해 크게 나타났다. 소금의 색도는 꽃소금의 L값이 천일염에 비해 높아 밝게 확인되었다. 관능검사 결과로 짠맛은 NaCl 함량과 유사하며, 쓴맛은 K과 Mg 함량이 적은 도초산 꽃소금이 낮게 나타났다. 천일염에 비해 꽃소금의 단맛과 기호도가 더 높은 것으로 확인되었다. 호염균 동정 결과 19종 모두 Firmicutes로 꽃소금에서 Marinibacillus, Paenibacillus, Bacillus 속이 12종으로 확인되며, 천일염은 Planococcus, Staphylococcus, Bacillus 속 3종으로 검출되었다. DGGE 실험 결과로 도초산 꽃소금에서 16개의 band와 도초산 천일염에서 15개의 band를 확인하였다. 동정 결과 도초산 꽃소금에서 Cupriavidus sp. ATHA3(14.43%), Cupriavidus sp. TSA5(10.41%), Maritimibacter sp. YCSD61-2(8.13%), uncultured bacteria(68%)로 확인되었고, 도초산 천일염에서는 Dunaliella salina(4.76%), Cupriavidus sp. ATHA3(15.80%), uncultured Mycoplasmataceae bacteria(51.72%), uncultured bacteria(27%)로 확인되었다.

Peering into the matrix: A look at biofilms and their inherent antibiotic resistance

Biofilms are increasingly being regarded as the predominant form of bacterial growth in natural settings. These structures consist of bacterial cells immobilized at a surface and encased in a self-produced matrix of extracellular polymeric substances. In clinical settings, biofilms are the cause of persistent infections that are difficult to clear through the action of the host immune system. Biofilm-encased cells are also associated with increased levels of antibiotic resistance compared to their planktonic counterparts. The result is increased morbidity and mortality when biofilms are associated with disease. In this review, the focus of discussion will be the various mechanisms of antibiotic resistance common to biofilms and the role these mechanisms play in the pathogenesis of major clinically-relevant microorganisms. Antibiotic penetration, altered microenvironments, phenotypic variation, and adaptive resistance mechanisms are all key players in the development of antibiotic resistance in bacterial biofilms. Though the relative significance of each individual mechanism varies, when combined they confer extensive protection to the biofilm’s cellular populations.&#x0D; &#x0D; Keywords: biofilms; antibiotic resistance (mechanisms of); clinical applications; disease; antibiotic penetration; altered microenvironments; phenotypic variation; adaptive resistance; review

A novel arsenate reductase from the bacterium Thermus thermophilus HB27: Its role in arsenic detoxification

Microorganisms living in arsenic-rich geothermal environments act on arsenic with different biochemical strategies, but the molecular mechanisms responsible for the resistance to the harmful effects of the metalloid have only partially been examined. In this study, we investigated the mechanisms of arsenic resistance in the thermophilic bacterium Thermus thermophilus HB27. This strain, originally isolated from a Japanese hot spring, exhibited tolerance to concentrations of arsenate and arsenite up to 20mM and 15mM, respectively; it owns in its genome a putative chromosomal arsenate reductase (TtarsC) gene encoding a protein homologous to the one well characterized from the plasmid pI258 of the Gram+bacterium Staphylococcus aureus. Differently from the majority of microorganisms, TtarsC is part of an operon including genes not related to arsenic resistance; qRT-PCR showed that its expression was four-fold increased when arsenate was added to the growth medium. The gene cloning and expression in Escherichia coli, followed by purification of the recombinant protein, proved that TtArsC was indeed a thioredoxin-coupled arsenate reductase with a kcat/KM value of 1.2×104M−1s−1. It also exhibited weak phosphatase activity with a kcat/KM value of 2.7×10−4M−1s−1. The catalytic role of the first cysteine (Cys7) was ascertained by site-directed mutagenesis. These results identify TtArsC as an important component in the arsenic resistance in T. thermophilus giving the first structural–functional characterization of a thermophilic arsenate reductase.

Impact of volatile phenols and their precursors on wine quality and control measures of Brettanomyces/Dekkera yeasts

Volatile phenols are aromatic compounds and one of the key molecules responsible for olfactory defects in wine. The yeast genus Brettanomyces is the only major microorganism that has the ability to covert hydroxycinnamic acids into important levels of these compounds, especially 4-ethylphenol and 4-ethylguaiacol, in red wine. When 4-ethylphenols reach concentrations greater than the sensory threshold, all wine’s organoleptic characteristics might be influenced or damaged. The aim of this literature review is to provide a better understanding of the physicochemical, biochemical, and metabolic factors that are related to the levels of p-coumaric acid and volatile phenols in wine. Then, this work summarizes the different methods used for controlling the presence of Brettanomyces in wine and the production of ethylphenols.

BIOPROSPECÇÃO DE NOVOS GENES PARA A INDÚSTRIA USANDO METAGENOMA E BIOINFORMÁTICA

There is a growing demand for new enzymes that enable cost reduction and effi ciency improvement in industrial processes without harming the environment. Using classical methods of microbiology and biochemistry we can obtain less than 1% of the information contained in an environment. This is because the vast majority of microorganisms are not cultivable. Thanks to the advancement of metagenome and bioinformatics techniques, new possibilities for the industry are revealed. Here, the bioprospecting of the invasive snail microbiota for use in the biofuel industry is discussed.

A novel method for cultivating soil bacteria

Ribosomal RNA analyses of soil microbial communities consistently indicate that the majority of microorganisms in soil have never been cultivated or described in the laboratory. It has been suggested that microorganisms fail to grow in traditional culture media because the media fails to simulate the organisms' natural environment. We designed a unique culture technique that can cultivate an average of 40% and as high as 90% of the bacteria present in a soil sample. The 16S rDNA of 50 of these isolates were PCR amplified, sequenced, and analyzed. Nineteen, 26, 2 and 3 of the isolates were affiliated with the phyla Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes, respectively. Ten isolates possessed less than 98% sequence similarity to any previously characterized organism.

Clinical Significance of Prophylactic Antibiotics in Renal Transplantation

IntroductionThe use of new selective immunosuppressants as well as the emergence of new antimicrobial resistances raise the use of prophylactic antibiotics as a matter of controversy. The purpose of this study was to retrospectively analyze the clinical significance of prophylactic antibiotics in kidney transplantation. MethodsThis retrospective study included 174 renal allograft recipients who were divided into two groups: group A including patients who received perioperative prophylactic antibiotics and group B, who did not receive them. We analyzed who the incidence of infectious complications as well as the causative micro-organisms and their antimicrobial resistance within 1 month after kidney transplantation. ResultsOverall bacterial infections were observed during the first postoperative month in 13 cases (7.4%): 6 (3.4%) surgical site 4 (2.3%) urinary tract, 2 (1.1%) bacteremic, and 1 (0.6%) central catheter infections. There was no respiratory infection. The incidence of bacterial infection was not significantly different between the two groups. The major micro-organisms isolated after kidney transplantation, were Staphylococcus aureus and Escherichia coli; both of which had already shown multidrug resistance at the initial time of infection. ConclusionNot only did use of prophylactic antibiotics have little impact to prevent bacterial infections after kidney transplantation, but also it may induce antimicrobial resistance against the antibiotics used for prophylaxis. Moreover, the increased antibiotic resistance prior to kidney transplantation hampers the effectiveness of prophylactic antimicrobial agents. Guidelines for perioperative antibiotic prophylaxis should be therefore revised.

The Effect of Plant Extracts on In-vitro Ruminal Fermentation, Methanogenesis and Methane-related Microbes in the Rumen.

The effect on methanogens attached to the surface of rumen ciliate protozoa by the addition of plant extracts (pine needles and ginkgo leaves) was studied with particular reference to their effectiveness for decreasing methane emission. The plant extracts (pine needles and ginkgo leaves) were added to an in vitro fermentation incubated with rumen fluid. The microbial population including bacteria, ciliated-associated methanogen, four different groups of methanogens and Fibrobacter succinogenes were quantified by using the real-time PCR. Gas profiles including methane, carbon dioxide and hydrogen, and runinal fermentation characteristics were observed in vitro. The methane emission from samples with an addition of individual juices from pine needles, ginkgo leaves and 70% ethanol extract from ginko leaves was significantly lower (p<0.05, 27.1, 28.1 and 28.1 vs 34.0 ml/g DM) than that of the control, respectively. Total VFAs in samples with an addition of any of the plant extracts were significantly lower than that of the control (p<0.05) as well. The order Methanococcales and the order Methanosarcinales were not detected by using PCR in any incubated mixtures. The ciliate-associated methanogens population decreased from 25% to 49% in the plant extacts as compared to control. We speculate that the supplementation of juice from pine needles and ginkgo leaves extract (70% ethanol extract) decreased the protozoa population resulting in a reduction of methane emission in the rumen and thus inhibiting methanogenesis. The order Methanobacteriales community was affected by addition of all plant extracts and decreased to less than the control, while the order Methanomicrobiales population showed an increase to more than that of the control. The F. succinogenes, the major fibrolytic microorganism, population in all added plant extracts was increased to greater than that of the control. In conclusion, pine needles and ginkgo leaves extracts appear to have properties that decrease methanogenesis by inhibiting protozoa species and may have a potential for use as additives for ruminants.

Expression, purification, and biochemical properties of arginase from Bacillus subtilis 168

The arginine-degrading and ornithine-producing enzymes arginase has been used to treat arginine-dependent cancers. This study was carried out to obtain the microbial arginase from Bacillus subtilis, one of major microorganisms found in fermented foods such as Cheonggukjang. The gene encoding arginase was isolated from B. subtilis 168 and cloned into E. coli expression plasmid pET32a. The enzyme activity was detected in the supernatant of the transformed and IPTG induced cell-extract. Arginase was purified for homogeneity from the supernatant by affinity chromatography. The specific activity of the purified arginase was 150 U/mg protein. SDS-PAGE analysis revealed the molecular size to be 49 kDa (Trix·Tag, 6×His·Tag added size). The optimum pH and temperature of the purified enzyme with arginine as the substrate were pH 8.4 and 45°C, respectively. The Km and Vmax values of arginine for the enzyme were 4.6 mM and 133.0 mM/min/mg protein respectively. These findings can contribute in the development of functional fermented foods such as Cheonggukjang with an enhanced level of ornithine and pharmaceutical products by providing the key enzyme in arginine-degradation and ornithine-production.

Baicalin plays an anti-inflammatory role through reducing nuclear factor-κB and p38 phosphorylation in S. aureus-induced mastitis

Mastitis is an inflammatory disease caused by microbial infection. Staphylococcus aureus is the major etiological microorganism responsible for both clinical and subclinical mastitis in dairy cows. A mouse model of S. aureus mastitis is available. Baicalin is isolated from Scutellaria and is known to have anti-inflammatory properties. This study was designed to evaluate the effects of baicalin in S. aureus mastitis. In the present study, the mouse model was infected with S. aureus to cause mammary gland inflammation. Baicalin treatment was administered from 6h until 24h after infection. Baicalin significantly attenuated inflammatory cell infiltration and decreased levels of TNF-α, IL-β, and IL-6. Further studies revealed that baicalin downregulated phosphorylation of NF-κB and p38 in the mammary gland with S. aureus mastitis. Our results demonstrated that baicalin reduced the expression of the proinflammatory cytokines TNF-α, IL-β, and IL-6 by inhibiting NF-κB and p38 phosphorylation and mRNA expression.

Aetiology and antibiotic resistance patterns of urinary tract infections in the elderly: a 6-month study

Urinary tract infections (UTIs) are a common cause of bacteraemia in the elderly and are associated with a high probability of hospitalization. Despite the impact of UTIs on health status and quality of life, a limited number of studies have evaluated their aetiology in this population. This study aimed to evaluate the microbial aetiology and pattern of susceptibility of bacteria causing UTIs in the elderly. For this purpose, a retrospective cohort study of elderly residents (n = 472, aged >65 years) in 14 nursing homes in Milan (Italy) and its province was performed. Globally, 393 micro-organisms from 328 samples were isolated: Escherichia coli was the most prevalent (44.8 %), followed by Proteus mirabilis (20.4 %), Providencia spp. (8.9 %), Klebsiella spp. (6.4 %) and Pseudomonas aeruginosa (4.6 %). Enterococci were the most frequently isolated Gram-positive organisms (7.4 %). Almost all Enterobacteriaceae were susceptible to nitrofurantoin, carbapenems and amikacin. Extended-spectrum β-lactamases were detected in 42.1 % of isolates. The most active antibiotics against P. aeruginosa were colistin, amikacin and piperacillin/tazobactam. All Gram-positive organisms were susceptible to glycopeptides and linezolid, and 90 % were susceptible to nitrofurantoin. Fluoroquinolones showed a limited activity against all the tested micro-organisms. Escherichia coli remains the major micro-organism responsible for UTIs in older people, although to a lesser extent than in a younger population. The high rates of resistance observed in this study make careful use of antibiotics advisable to limit further development of resistance.