21 research outputs found

    Methicillin-Resistant Staphylococcus aureus in Raw Milk : Prevalence, SCCmec Typing, Enterotoxin Characterization, and Antimicrobial Resistance Patterns

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    Staphylococcus aureus is a known major cause of foodborne illnesses, and raw milk and dairy products are often contaminated by enterotoxigenic and antimicrobial-resistant S. aureus strains. In the present study, 35 S. aureus strains were isolated from 383 raw milk samples collected from various dairy herds in the province of Milan (northern Italy). The isolates were characterized based on their antimicrobial susceptibility patterns and the presence of genes encoding staphylococcal enterotoxins (sea, seb, sec, sed, and see). About half (45.7%) of the strains were enterotoxigenic, and 37.1% were resistant to at least one of the antimicrobial drugs tested. Seven (20%) of 35 isolates were identified as methicillin-resistant S. aureus (MRSA), and SCCmec typing performed with a multiplex PCR assay revealed the presence of gene cassettes IV and V, typical of community acquired MRSA, and I and II, characteristic of health care\u2013associated MRSA. The MRSA strains were evaluated for the presence of the Panton-Valentine leukocidin gene, but this gene was not found. The results of the present study revealed the presence of toxin-producing S. aureus and MRSA strains in raw milk. MRSA and enterotoxigenic S. aureus in dairy farms are an important risk factor for the spread of staphylococcal infections; therefore, further studies are needed to find strategies for monitoring and controlling the presence of S. aureus, especially MRSA, in dairy products

    A histological procedure to study fungal infection in the wax moth Galleria mellonella

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    The invertebrate model Galleria mellonella is a widely used factitious host to study the microbial pathogenesis in vivo. However, a specific procedure for the recovery and the processing of the infected tissues, important for a better understanding of the host-pathogen interactions, has not been reported to our knowledge. In the present study we describe a new procedure of fixation and processing of larval tissue that allows studying the larval topographic anatomy and assessing the morphological changes due to the fungal infection. Lepidopteran larvae were infected with Candida albicans strains displaying various biofilm-forming abilities. The whole larvae were then examined for tissue changes by histological techniques. We show that comparing cutting planes, serial transversal sections of paraffin-embedded larva result in better accuracy and information recovering. Using this technique, it was possible to preserve the integrity of G. mellonella internal structures allowing the detailed analysis of morphological differences in different experimental groups (i.e., healthy vs infected larvae). We were also able to study strain-related differences in the pathogenesis of C. albicans by observing the immune response elicited and the invasiveness of two isolates within the larval tissues.\ua0In general, by processing the whole larva and optimizing routinely histochemical stainings, it is possible to visualize and analyse infected tissues. Various degrees of pathogenicity (strain- or inoculum-related), and the infection time course can be described in details. Moreover, the host immune response events can be followed throughout the infectious process leading to a comprehensive picture of the studied phenomenon

    The Reflective Fostering Programme: background and development of a new approach

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    Looked after children represent a vulnerable group in society, many of whom are exposed to maltreatment, particularly in the form of relational trauma, prior to placement with a foster family. Challenging behaviours can place foster placements at risk and looked after children often confront the possibility of placement breakdown. A carer’s capacity to retain a robust understanding of the children in their care as autonomous individuals with needs, feelings and thoughts can be important in enabling them to respond more effectively to the worrying or disruptive behaviour they may encounter. The Reflective Fostering Programme (RFP) is a new group-based programme aiming to support foster carers of children aged 4–11. This innovative development follows calls by the National Institute for Health and Care Excellence (NICE) and other organisations to help improve outcomes for children in care by improving resources for their carers. The RFP is rooted in evidence drawn from the field of contemporary attachment and mentalizing research, which indicates that children who have a carer high in reflective functioning tend to have more favourable outcomes in terms of social-emotional well-being. It also draws on the evidence that looking after a child who has impaired capacity to mentalize as a result of early relational trauma affects the carer’s capacity to mentalize and respond sensitively to the child (Ensink, et al., 2015). This article sets out the rationale for the RFP, outlines its key elements and concludes by indicating future service implementation and a planned feasibility study examining this approach

    Repurposing Pilocarpine Hydrochloride for Treatment of Candida albicans Infections

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    Acetylcholine modulates the virulence of Candidaalbicans and regulates an appropriate immune response to infection in a Galleria mellonella infection model. Indeed, the evidence suggests that C. albicans possesses a functional cholinergic receptor that can regulate filamentous growth and biofilm formation. Furthermore, G. mellonella immune cell subsets possess repertories of cholinergic receptors which regulate an effective and appropriate cellular immune response to C. albicans infection. This study aimed to investigate the cholinergic receptor subtype involved in regulation of filamentous growth and biofilm formation by C. albicans and determine the roles of cholinergic receptors in modulation of G. mellonella immune cell subsets. The general muscarinic receptor agonist, pilocarpine hydrochloride, inhibited C. albicans biofilm formation and pathogenicity, a phenomenon that could be reversed using the general muscarinic receptor antagonist, scopolamine. Pilocarpine hydrochloride protected G. mellonella larvae from C. albicans infection via inhibition of C. albicans filamentation and appropriate regulation of cellular immunity. However, scopolamine abrogated the capacity of pilocarpine hydrochloride to protect G. mellonella larvae from C. albicans infection. Furthermore, acetylcholine and pilocarpine hydrochloride exhibited differential modulatory capabilities on Galleria mellonella hemocyte responses to C. albicans The data in this article demonstrate that a muscarinic receptor modulates C. albicans filamentation and biofilm formation. Furthermore, the results suggest that G. mellonella hemocyte subsets possess unique repertoires of cholinergic receptors that regulate their differentiation, activation, and function in contrasting manners. Therefore, targeting cholinergic receptors by repurposing currently licensed cholinergic drugs may offer novel therapeutic solutions for the prevention or treatment of fungal infections.IMPORTANCECandida albicans is the most common human fungal pathogen with an estimated crude mortality rate of 40%. The ability of the organism to switch from the yeast to hyphal form and produce biofilms are important virulence factors. C. albicans infections are combatted by the host immune system. However, Candida triggers a strong inflammatory response that, if not appropriately regulated, can damage host tissues. Therefore, it is important that the host immune response eliminates the fungus but limits tissue damage. This study provides evidence that targeting cholinergic receptors cannot only curb the virulence of C. albicans by inhibiting filamentous growth and biofilm formation but can also appropriately regulate the host immune response to induce rapid clearance with limited damage to vital tissues. This article provides evidence that repurposing licensed drugs that target cholinergic receptors may offer novel therapeutic solutions for the prevention or treatment of fungal infections

    Prevalence, Outcome, and Prevention of Congenital Cytomegalovirus Infection in Neonates Born to Women with Preconception Immunity (CHILd Study)

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    Background: Human cytomegalovirus (HCMV) is the leading infectious cause of congenital disabilities. We designed a prospective study to investigate the rate, outcome, and risk factors of congenital CMV (cCMV) infection in neonates born to immune women, and the potential need and effectiveness of hygiene recommendations in this population. Methods: The study was composed of 2 sequential parts: an epidemiology (part 1) and a prevention (part 2) study. Performance of part 2 depended upon a cCMV rate >0.4%. Women enrolled in part 1 did not receive hygiene recommendations. Newborns were screened by HCMV DNA testing in saliva and cCMV was confirmed by urine testing. Results: Saliva swabs were positive for HCMV DNA in 45/9661 newborns and cCMV was confirmed in 18 cases. The rate of cCMV was. 19% (95% confidence interval [CI]:. 11-.29%), and 3 out of 18 infants with cCMV had symptoms of CMV at birth. Age, nationality, occupation, and contact with children were similar between mothers of infected and noninfected newborns. Twin pregnancy (odds ratio [OR]: 7.2; 95% CI: 1.7-32.2; P =. 037) and maternal medical conditions (OR: 3.9; 95% CI: 1.5-10.1; P =. 003) appeared associated with cCMV. Given the rate of cCMV was lower than expected, the prevention part of the study was cancelled. Conclusions: Newborns from women with preconception immunity have a low rate of cCMV, which appears to be mostly due to reactivation of the latent virus. Therefore, serological screening in childbearing age would be pivotal to identify HCMV-seropositive women, whose newborns have a low risk of cCMV. Clinical trials registration: www.clinicaltrials.gov (NCT03973359)

    Experimental biofilm-related candida infections

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    AIM. We investigated the pathogenic role of biofilm and the therapeutic efficacy of anidulafungin in experimental infections of the wax moth Galleria mellonella by C. albicans clinical strains. MATERIALS AND METHODS. On the basis of the in vitro propensity to form biofilm, five biofilm-producer (BP) and four non-producer (NP) C. albicans clinical strains were used in this study. For each strain, we assessed the virulence by infecting G. mellonella larvae and observing survival. Anidulafungin was administered two hours after yeast inoculum at 0.6 \u3bcg, according to the therapeutic dose recommended for humans. RESULTS. Biofilm-forming ability highly influenced the larvae-killing rate. A significant (p<0.0001) survival decrease was observed in the BP group, with 80% of the infected larvae dying within 72 hours. NP isolates did not reach the same killing rate, even at the end of experiments (216 h). Larval survival was enhanced (p<0.0001) by anidulafungin administration in both groups. Survival rate at 72 hours was similar in both (BP 78.5% and NP 87.5%), whereas there were still differences at the end of experiments with a higher survival in the NP group (75% versus 48%). CONCLUSIONS. Our data confirm the pathogenic role of biofilm in C. albicans infections. Its importance was further enhanced by lack of contribution of extracellular enzymes, detected in both NP and BP strains. In addition, we demonstrated anidulafungin efficacy in treating biofilm-related invasive candidiasis

    Antifungal resistance does not necessarily affect Candida glabrata fitness

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    Although there has been an overall good coverage of Candida glabrata infections by the echinocandins, emergence of antifungal resistance during therapy has been reported. We investigated, by using an invertebrate host model, the fitness of sequential C. glabrata isolates with different echinocandins susceptibility patterns. The studied strains were isolated from a case of recurrent fungemia with a fatal outcome due to C. glabrata that developed cross-resistance to echinocandins during caspofungin therapy. The sequential strains isolated post-therapy showed a S663P mutation in the Fks2p hot spot 1. In vivo study in the invertebrate host Galleria mellonella did not suggest a fitness cost related to the acquired antifungal resistance, the three isolates displayed a similar rate of killing (P=0.54). We observed a clear correlation between emergence of antifungal resistance and persistence of the causal agent, probably aided by the unchanged fitness and unresponsiveness in vivo to the adopted therapy
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