Fruits are among the main natural sources of phenolic compounds (PC). These compounds exert important antioxidant properties primarily associated with the presence of hydroxyl groups in their ...molecular structure. Additionally, the antibacterial effects of fruit phenolic-rich extracts or individual PC commonly found in fruits have been an emerging research focus in recent years. This review discusses by first time the available literature regarding the inhibitory effects of fruit PC on pathogenic bacteria, including not only their direct effects on bacterial growth and survival, but also their effects on virulence factors and antibiotic resistance, as well as the possible mechanism underlying these inhibitory properties. The results of the retrieved studies show overall that the antibacterial effects of fruit PC vary with the target bacteria, type of PC and length of exposure to these compounds. The type of solvent and procedures used for extraction and fruit cultivar also seem to influence the antibacterial effects of phenolic-rich fruit extracts. Fruit PC have shown wide-spectrum antibacterial properties besides being effective antibiotic resistance modifying agents in pathogenic bacteria and these effects have shown to be associated with interruption of efflux pump expression/function. Furthermore, fruit PC can cause down regulation of a variety of genes associated with virulence features in pathogenic bacteria. Results of available studies indicate the depolarization and alteration of membrane fluidity as mechanisms underlying the inhibition of pathogenic bacteria by fruit PC. These data reveal fruit PC have potential antimicrobial properties, which should be rationally exploited in solutions to control pathogenic bacteria.
•Fruit phenolic (FP) exert wide-spectrum inhibitory effects on pathogenic bacteria.•Inhibitory effects of FP vary with target bacteria, type of FP and length of exposure.•FP are effective antibiotic resistance modifying agents in pathogenic bacteria.•FP down regulates genes associated with virulence features in pathogenic bacteria.•FP should be exploited in solutions to control pathogenic bacteria.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study aimed to evaluate the inhibitory effects of phenolic‐rich extracts from acerola (Malpighia emarginata D.C., PEA), cashew apple (Anacardium occidentale L., PEC) and mango (Mangifera indica ...L., PEM) by‐products on distinct enterotoxigenic Escherichia coli (ETEC) strains. The capability of PEA and PEC of impairing various physiological functions of ETEC strains was investigated with multiparametric flow cytometry. Procyanidin B2, myricetin and p‐coumaric acid were the major phenolic compounds in PEA, PEC and PEM, respectively. PEA and PEC had lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) (MIC: 31·25 mg ml−1; MBC: 62·5 mg ml−1) on ETEC strains than PEM (MIC and MIC: >1000 mg ml−1). PEA and PEC (15·6, 31·2, 62·5 mg ml−1) caused viable count reductions (P < 0·05) on ETEC strains after 24 h of exposure, notably the ≥3 log reductions caused by 62·5 mg ml−1. The 24 h exposure of ETEC strains to PEA and PEC (31·2, 62·5 mg ml−1) led to high sizes of cell subpopulations with concomitant impairments in cell membrane polarization and permeability, as well as in enzymatic, respiratory and efflux activities. PEA and PEC are effective in inhibiting ETEC through a multi‐target action mode with disturbance in different physiological functions.
Significance and Impact of the Study: Enterotoxigenic Escherichia coli (ETEC) is one of the main causes of diarrhoea in humans and animals. The increasing resistance of ETEC strains to clinically relevant antibiotics has prompt the necessity to search for novel substances with inhibitory efficacy. This is the first study showing the capability of phenolic‐rich extracts of acerola and cashew apple by‐products causing the inhibition of distinct ETEC strains, with disturbance of various physiological functions, indicating these substances as potential antimicrobials to be exploited in solutions to control ETEC in humans and animals.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Enteroaggregative Escherichia coli (EAEC) heat-stable toxin 1 (EAST1) is a small toxin of proteic nature. The reference strain producing this toxin was originally detected in the stools of a ...diarrheic Chilean child. Today, we know that EAST1 is not solely associated with EAEC but also with many other diarrheic E. coli families. Some studies have established the role of EAST1 in human outbreaks of diarrhea. In addition, isolates from farm animals were shown, more recently, to carry the astA gene coding for EAST1. However, the relation between the presence of EAST1 and disease is not conclusive. In this article, the current state of the knowledge on the presence and probable role of EAST1 in farm animal diseases is reviewed and discussed.
Allopurinol is the most commonly used urate-lowering therapy, with rare but potentially fatal adverse effects. However, its impact on overall mortality remains largely unknown. In this study, we ...evaluated the impact of allopurinol initiation on the risk of mortality among individuals with hyperuricaemia and among those with gout in the general population.
We conducted an incident user cohort study with propensity score matching using a UK general population database. The study population included individuals aged ≥40 years who had a record of hyperuricaemia (serum urate level >357 μmol/L for women and >416 μmol/L for men) between January 2000 and May 2010. To closely account for potential confounders of allopurinol use and risk of death, we constructed propensity score matched cohorts of allopurinol initiators and comparators (non-initiators) within 6-month cohort accrual blocks.
Of 5927 allopurinol initiators and 5927 matched comparators, 654 and 718, respectively, died during the follow-up (mean=2.9 years). The baseline characteristics were well balanced in the two groups, including the prevalence of gout in each group (84%). Allopurinol initiation was associated with a lower risk of all-cause mortality (matched HR 0.89 (95% CI 0.80 to 0.99)). When we limited the analysis to those with gout, the corresponding HR was 0.81 (95% CI 0.70 to 0.92).
In this general population study, allopurinol initiation was associated with a modestly reduced risk of death in patients with hyperuricaemia and patients with gout. The overall benefit of allopurinol on survival may outweigh the impact of rare serious adverse effects.
A Streptococcus suis surface protein reacting with convalescent-phase sera from pigs clinically infected by S. suis type 2 was identified. The apparent 110-kDa protein, designated Sao, exhibits ...typical features of membrane-anchored surface proteins of gram-positive bacteria, such as a signal sequence and an LPVTG membrane anchor motif. In spite of high identity with the partially sequenced genomes of S. suis Canadian strain 89/1591 and European strain P1/7, Sao does not share significant homology with other known sequences. However, a conserved avirulence domain that is often found in plant pathogens has been detected. Electron microscopy using an Sao-specific antiserum has confirmed the surface location of the Sao protein on S. suis. The Sao-specific antibody reacts with cell lysates of 28 of 33 S. suis serotypes and 25 of 26 serotype 2 isolates in immunoblots, suggesting its high conservation in S. suis species. The immunization of piglets with recombinant Sao elicits a significant humoral antibody response. However, the antibody response is not reflected in protection of pigs that are intratracheally challenged with a virulent strain in our conventional vaccination model.
Escherichia coli O78 strains are frequently associated with extraintestinal diseases, such as airsacculitis and septicemia, in poultry, livestock, and humans. To understand the influence of the pst ...operon in the virulence of E. coli, we introduced mutations into the pst genes of the avian pathogenic E. coli (APEC) O78:K80 strain chi7122 by allelic exchange. The mutation of pst genes led to the constitutive expression of the Pho regulon. Furthermore, the virulence of APEC strain chi7122 in a chicken infection model was attenuated by inactivation of the Pst system. The pst mutant caused significantly fewer extraintestinal lesions in infected chickens, and bacterial numbers isolated from different tissues after infection were significantly lower for the mutant than for the wild-type strain. Moreover, resistance to the bactericidal effects of rabbit serum and acid shock was impaired in the pst mutant, in contrast to the wild-type strain. In addition, the MIC of polymyxin was twofold lower for the mutant than for the wild-type strain. Although the pst mutant demonstrated an increased susceptibility to rabbit serum, this strain was not killed by chicken serum, suggesting the presence of differences in host innate immune defenses and complement-mediated killing. In APEC O78 strain chi7122, a functional Pst system is required for full virulence and resistance to acid shock and polymyxin. Our results suggest that the mutation of pst genes induces a deregulation of phosphate sensing and changes in the cell surface composition that lead to decreased virulence, indicating the importance of the Pst system for the virulence of pathogenic E. coli strains from different hosts.
OBJECTIVE: The authors investigated the theoretical and clinical role of depression among cocaine abusers in treatment. METHOD: Eighty-nine cocaine-abusing patients underwent 2 weeks of substance ...abuse treatment. Posttreatment major depressive disorder, depressive symptoms before and after substance abuse treatment, and alcohol diagnoses were assessed and their relation to pretreatment substance use, cravings in high-risk situations, and 3-month follow-up status was examined. RESULTS: High rates of major depressive disorder were found but were unrelated to pretreatment substance use. The decrease in depressive symptoms during treatment was independent of major depressive disorder or alcohol diagnoses and predicted treatment attrition. Higher levels of depressive symptoms during treatment were associated with greater urge to use cocaine, alcohol, and other drugs in high-risk situations. Concurrent major depressive disorder and depressive symptoms did not predict cocaine use at follow-up. However, patients who had an alcohol relapse episode experienced more depressive symptoms during treatment than did those who abstained. CONCLUSIONS: The results highlight the relationship of depression to alcohol use among cocaine abusers and suggest a need for further studies of the association between depression and substance use disorders. (Am J Psychiatry 1998; 155:220-225)
Dysregulation of platelet‐derived growth factor receptor (PDGFR) may play a role in feline injection‐site sarcoma (ISS) cell growth and viability. Masitinib, a tyrosine kinase inhibitor approved for ...treatment of canine mast cell tumours, is highly selective for the PDGFR signalling pathway and may offer a new therapeutic approach for this disease. The in vitro effects of masitinib on growth, apoptosis and PDGFR signalling in two novel ISS cell lines were investigated. PDGFR expression was confirmed by Western blot in cell lines derived from a primary ISS tumour (JB) and a corresponding, histologically confirmed ISS lung metastasis (JBLM). Masitinib inhibited cell growth and PDGFR phosphorylation in both cell lines. Higher drug concentrations were required to inhibit growth than to modulate ligand‐induced autophosphorylation of PDGFR. These in vitro data suggest that masitinib displays activity against both primary and metastatic ISS cell line and may aid in the clinical management of ISS.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
10.
Escherichia coli STb enterotoxin Dubreuil, J Daniel
Microbiology (Society for General Microbiology),
06/1997, Volume:
143 ( Pt 6)
Journal Article
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