6Lisbon Oceanarium, 1999-005 Lisbon, Portugal A global phylogeny for chelonid fibropapilloma-associated herpesvirus (CFPHV), the most likely aetiological agent of fibropapillomatosis (FP) in sea turtles, was inferred, using dated sequences, through Bayesian Markov chain Monte Carlo analysis and used to estimate the virus evolutionary rate independent of the evolution of the host, and to resolve the phylogenetic positions of new haplotypes from Puerto Rico and the Gulf of Guinea. Four phylogeographical groups were identified: eastern Pacific, western Atlantic/eastern Caribbean, mid-west Pacific and Atlantic. The latter comprises the Gulf of Guinea and Puerto Rico, suggesting recent virus gene flow between these two regions. One virus haplotype from Florida remained elusive, representing either an independent lineage sharing a common ancestor with all other identified virus variants or an Atlantic representative of the lineage giving rise to the eastern Pacific group. The virus evolutionary rate ranged from 1.62¾10 "4 to 2.22¾10 "4 substitutions per site per year, which is much faster than what is expected for a herpesvirus. The mean time for the most recent common ancestor of the modern virus variants was estimated at 192.90-429.71 years ago, which, although more recent than previous estimates, still supports an interpretation that the global FP pandemic is not the result of a recent acquisition of a virulence mutation(s). The phylogeographical pattern obtained seems partially to reflect sea turtle movements, whereas altered environments appear to be implicated in current FP outbreaks and in the modern evolutionary history of CFPHV. INTRODUCTIONChelonid fibropapilloma-associated herpesvirus (CFPHV) is the most likely aetiological agent of fibropapillomatosis (FP) (Arthur et al., 2008a;Greenblatt et al., 2005;Lackovich et al., 1999;Quackenbush et al., 1998), a neoplastic disease of sea turtles, characterized by recent outbreaks (Diez et al., 2010;Foley et al., 2005;Work & Balazs, 1999). The tumours can be both external and internal and, although benign, depending on location and size, they may obstruct crucial functions such as swimming, feeding and sight, or may impede organ function (Herbst, 1994;Herbst & Klein, 1995). Severe FP also leads to bacteraemia (Work et al., 2003). The most susceptible life stages appear to be neritic juveniles and subadults, whereas in adults the disease is rare (Ene et al., 2005;Herbst & Klein, 1995;Work et al., 2004). A high prevalence of FP is common in anthropogenically altered environments (Aguirre & Lutz, 2004;Herbst, 1994;Van Houtan et al., 2010), suggesting that factors in these environments promote disease outbreaks, for example, through the enhancement of virus transmissibility and/or the enhancement of disease expression via substances thatThe GenBank/EMBL/DDBJ accession numbers for the CFPHV sequences determined in this study are JN580279-JN580296 and JN625251-JN625262.Further details about samples are available with the online version of this paper. Phylogenies of herpesv...
BackgroundFoot infections are a major cause of morbidity in people with diabetes and the most common cause of diabetes-related hospitalization and lower extremity amputation. Staphylococcus aureus is by far the most frequent species isolated from these infections. In particular, methicillin-resistant S. aureus (MRSA) has emerged as a major clinical and epidemiological problem in hospitals. MRSA strains have the ability to be resistant to most β-lactam antibiotics, but also to a wide range of other antimicrobials, making infections difficult to manage and very costly to treat. To date, there are two fifth-generation cephalosporins generally efficacious against MRSA, ceftaroline and ceftobripole, sharing a similar spectrum.Biofilm formation is one of the most important virulence traits of S. aureus. Biofilm growth plays an important role during infection by providing defence against several antagonistic mechanisms. In this study, we analysed the antimicrobial susceptibility patterns of biofilm-producing S. aureus strains isolated from diabetic foot infections. The antibiotic minimum inhibitory concentration (MIC) was determined for ten antimicrobial compounds, along with the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC), followed by PCR identification of genetic determinants of biofilm production and antimicrobial resistance.ResultsResults demonstrate that very high concentrations of the most used antibiotics in treating diabetic foot infections (DFI) are required to inhibit S. aureus biofilms in vitro, which may explain why monotherapy with these agents frequently fails to eradicate biofilm infections. In fact, biofilms were resistant to antibiotics at concentrations 10–1000 times greater than the ones required to kill free-living or planktonic cells. The only antibiotics able to inhibit biofilm eradication on 50 % of isolates were ceftaroline and gentamicin.ConclusionsThe results suggest that the antibiotic susceptibility patterns cannot be applied to biofilm established infections. Selection of antimicrobial therapy is a critical step in DFI and should aim at overcoming biofilm disease in order to optimize the outcomes of this complex pathology.
A survey of infectious and parasitic diseases of stray cats was carried out using biological samples collected from animals captured during a catch-neuter-release programme in four counties of the Lisbon Metropolitan Area. The main objective was to investigate the potential threat of stray cats for animal and public health. Samples of blood, stool, hair and auricular swabs were collected from 231 cats in 27 colonies. Anti-Toxoplasma gondii antibodies were detected in 47/194 samples (24.2%); anti-Leishmania infantum antibodies in 1/180 cats (0.6%); intestinal parasites in 23/74 samples (Toxocara cati, Isospora felis, Ancylostoma tubaeforme, Dipylidium caninum, Uncinaria stenocephala, Toxascaris leonina) and Otodectes cynotis in 4/182 cats (2.2%); dermatophyte fungi were isolated in 40/136 samples (29.4%); feline immunodeficiency virus antibodies were detected in 23/226 samples (10.2%); feline leukaemia virus antigen in 14/198 samples (7.1%); and feline coronavirus RNA in 9/127 samples (7.1%). Our results revealed that zoonotic agents, namely dermatophyte fungi and Toxocara cati were present in stray cat colonies in the investigated counties. Overall the low frequency of major pathogens suggests a balanced relationship between host and agents.
Feline Immnunodeficiency (FIV) and Feline Leukemia (FeLV) viruses are common infectious agents in stray cats and shelter environments. Recombinant feline interferon-ω (rFeIFNω) has shown an antiviral action not only against FIV and FeLV but also against herpesvirus (FHV-1) and calicivirus (FCV). Sixteen naturally infected FIV/FeLV cats were followed during rFeIFNω therapy in order to monitor clinical signs and to correlate with excretion of concomitant viruses (FCV, FHV-1, feline coronavirus (FCoV) and parvovirus (FPV)). Cats were submitted to clinical evaluations and concomitant virus excretion assessement. Comparing D0-D65, 10/16 cats improved clinical scores. Of the 10 cats positive for FHV-1 on D0, 4 were negative and 6 reduced viral loads. Of the 11 FCoV positive cats, 9 reduced viral loads. The 13 FCV positive cats and the FPV positive cat were negative on D65. In conclusion, rFeIFNω improves clinical signs and reduces concurrent viral excretion in naturally infected retroviral cats.
Diabetic patients frequently develop diabetic foot ulcers (DFUs), particularly those patients vulnerable to Staphylococcus aureus opportunistic infections. It is urgent to find new treatments for bacterial infections. The antimicrobial peptide (AMP) nisin is a potential candidate, mainly due to its broad spectrum of action against pathogens. Considering that AMP can be degraded or inactivated before reaching its target at therapeutic concentrations, it is mandatory to establish effective AMP delivery systems, with the natural polysaccharide guar gum being one of the most promising. We analysed the antimicrobial potential of nisin against 23 S. aureus DFU biofilm-producing isolates. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were determined for nisin diluted in HCl and incorporated in guar gum gel. Statistical analysis was performed using the Wilcoxon matched-pair test. Nisin was effective against all isolates, including some multidrug-resistant clinical isolates, independent of whether it is incorporated in guar gum. While differences among MIC, MBC and MBIC values were observed for HCl- and guar gum- nisin, no significant differences were found between MBEC values. Inhibitory activity of both systems seems to differ only twofold, which does not compromise guar gum gel efficiency as a delivery system. Our results highlight the potential of nisin as a substitute for or complementary therapy to current antibiotics used for treating DFU infections, which is extremely relevant considering the increase in multidrug-resistant bacteria dissemination. The guar gum gel represents an alternative, practical and safe delivery system for AMPs, allowing the development of novel topical therapies as treatments for bacterial skin infections.
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