Vittorio Fisichella

Bio: Vittorio Fisichella is an academic researcher from University of Messina. The author has contributed to research in topics: Antibiotic resistance & Serotype. The author has an hindex of 7, co-authored 18 publications receiving 240 citations.

Pathogenic microorganisms carried by migratory birds passing through the territory of the island of Ustica, Sicily (Italy)

Abstract: Several studies have shown that migratory birds play an important role in the ecology, circulation and dissemination of pathogenic organisms. In October 2006, a health status evaluation was performed on a large population of migratory birds passing through the territory of Ustica (Italy), an island located on the migration route of many species of birds to Africa, and various laboratory tests were conducted. In total, 218 faecal swabs and the internal organs of 21 subjects found dead in nets were collected for bacteriological and virological examination, including avian influenza and Newcastle disease. In addition, 19 pooled fresh faecal samples were collected for mycological examination. The bacteriological analysis produced 183 strains belonging to 28 different species of the Enterobacteriaceae family. In particular, Salmonella bongori, Yersinia enterocolitica and Klebsiella pneumonia strains were isolated. Almost all of the isolates were susceptible to sulphamethoxazole/trimethoprime (99.4%), cefotaxime (98.9%), nalidixic acid (96.7%), chloramphenicol (95.6%), and tetracycline (93.4%). Alternatively, many strains were resistant to ampicillin (42.6%), amoxicillin-clavulanic acid (42.6%), and streptomycin (43.7%). According to reverse transcriptase-polymerase chain reaction analysis, all of the samples were negative for the M gene of avian influenza virus. Moreover, isolation tests conducted on specific pathogen free eggs were negative for avian influenza and Newcastle disease. Several hyphomycetes and yeasts belonging to different genera were present in the specimens, and Cryptococcus neoformans was observed in a pooled faecal sample. Antibiotic resistance in wildlife can be monitored to evaluate the impact of anthropic pressure. Furthermore, migratory birds are potential reservoirs of pathogenic agents; thus, they can be regarded as sentinel species and used as environmental health indicators.

Detection of methicillin-resistant Staphylococcus aureus (MRSA) in the microbial flora from the conjunctiva of healthy donkeys from Sicily (Italy)

Abstract: Objective To describe the bacterial flora present in the normal conjunctiva of donkeys from Sicily (Italy). Animals studied A total of 46 healthy donkeys housed in 3 locations within the territory of Palermo (Sicily, Italy) were studied. Donkeys ranged from 2 to 13 years of age, with a median age of 6 years. Procedures Forty-six conjunctival swabs were obtained from both eyes of each animal, and specimens were cultured for aerobic bacteria. Furthermore, the antimicrobial activity of methicillin (1 μg) and oxacillin (5 μg) on Staphylococcus spp. isolates was evaluated, and a specific PCR assay, which allows the detection of mecA gene specific for methicillin-resistant Staphylococcus aureus (MRSA) strains, was performed. Results Forty of 46 (86.9%) donkeys were positive for bacteria. Eighty bacterial isolates, representing 9 bacteria genera, were successfully cultured. The most frequently recovered bacterial genus was Staphylococcus (52/80 isolates; 65%). Several strains (20/80 isolates; 25%) belonging to the Enterobacteriaceae family were also isolated, among which the most frequently isolated genus was Enterobacter (eight isolates). Of the 52 Staphylococcus spp. isolates, 14 (26.9%) strains were oxacillin/methicillin resistant. The mecA gene was detected in 6/52 (11.5%) strains. Conclusions This study contributes to the knowledge about normal ocular flora and MRSA occurrence in donkey farms in Sicily.

Antibiotic resistance assessment in bacteria isolated in migratory Passeriformes transiting through the Metaponto territory (Basilicata, Italy)

Abstract: Wild birds are considered to be reservoirs of human enteric pathogens and vectors of antimicrobial resistance dissemination in the environment. During their annual migration, they play a potential role in the epidemiology of human associated zoonoses. The aim of this study was to investigate the frequency of isolation and antimicrobial susceptibility profiles of microorganisms found in the cloaca of common European passerines. One hundred and twenty-one cloacal swabs were collected during a monitoring program of migratory birds in the Forest Reserve for Protection “Metaponto” (Basilicata, Italy). All samples were cultured using standard bacteriological methods and antibiotic susceptibility testing (agar disk diffusion test) of isolated strains was performed. The bacteriological analysis produced 122 strains belonging to 18 different species. The most commonly isolated species were Enterobacter cloacae and Providencia rettgeri (21 strains, 17.2%). Potentially pathogenic species including Klebsiella pneumoniae, Serratia marcescens and Pseudomonas spp. have also been identified. Isolates showed significant frequencies of antimicrobial resistance. The highest frequency of resistance was observed against amoxicillin (n = 79, 64.8%); ampicillin (n = 77, 63.1%); rifampicin (n = 75, 61.5%); amoxicillin–clavulanic acid (n = 66, 54.1%). Thirty-one strains (25.4%) showed resistance to imipenem and 8 (6.6%) to meropenem. Migratory birds play an important role in the ecology, circulation and dissemination of potentially pathogenic antimicrobial resistant organisms. They can therefore be considered sentinel species and environmental health indicators. Our results suggest that the integration of epidemiological surveillance networks during ringing campaigns of wild species can be an effective tool to study this phenomenon.

Significance and Roles of Proteus spp. Bacteria in Natural Environments

Abstract: Proteus spp. bacteria were first described in 1885 by Gustav Hauser, who had revealed their feature of intensive swarming growth. Currently, the genus is divided into Proteus mirabilis, Proteus vulgaris, Proteus penneri, Proteus hauseri, and three unnamed genomospecies 4, 5, and 6 and consists of 80 O-antigenic serogroups. The bacteria are known to be human opportunistic pathogens, isolated from urine, wounds, and other clinical sources. It is postulated that intestines are a reservoir of these proteolytic organisms. Many wild and domestic animals may be hosts of Proteus spp. bacteria, which are commonly known to play a role of parasites or commensals. However, interesting examples of their symbiotic relationships with higher organisms have also been described. Proteus spp. bacteria present in soil or water habitats are often regarded as indicators of fecal pollution, posing a threat of poisoning when the contaminated water or seafood is consumed. The health risk may also be connected with drug-resistant strains sourcing from intestines. Positive aspects of the bacteria presence in water and soil are connected with exceptional features displayed by autochthonic Proteus spp. strains detected in these environments. These rods acquire various metabolic abilities allowing their adaptation to different environmental conditions, such as high concentrations of heavy metals or toxic substances, which may be exploited as sources of energy and nutrition by the bacteria. The Proteus spp. abilities to tolerate or utilize polluting compounds as well as promote plant growth provide a possibility of employing these microorganisms in bioremediation and environmental protection.

Antimicrobial resistance in wildlife

Abstract: Summary The spread of antimicrobial resistance is of major concern for human health and leads to growing economic costs. While it is increasingly hypothesized that wildlife could play an important role in antimicrobial-resistant bacteria dynamics, empirical data remain scarce. The present work builds on a systematic review of the available data in order to highlight the main information we have and to suggest research pathways that should be followed if we aim to fill the gaps in our current knowledge. To achieve this goal, we address four questions: (i) Which resistant bacteria are the most frequently observed in wildlife? (ii) How are resistant bacteria exchanged between wildlife and the other hosts involved? (iii) In which habitats are those resistant bacteria found? (iv) Are resistances associated with certain ecological traits of the host? Synthesis and applications. We highlight the strong link existing between the impact of human activities on natural habitats and the carriage of antimicrobial-resistant bacteria by wildlife. Furthermore, we underline that omnivorous, anthropophilic and carnivorous species are at high risk of being carriers and potentially spreaders of antimicrobial-resistant bacteria. Identifying among those groups key sentinel species may be of particular interest to implement ecosystem contamination surveillance. Finally, we discuss possible exchange routes for antimicrobial-resistant bacteria between humans and wildlife. Considering that water is of major importance in those exchanges, a critical way to control antimicrobial resistance spread may be to limit aquatic environment contamination by antimicrobial-resistant bacteria and antibiotics.

The Ocean as a Global Reservoir of Antibiotic Resistance Genes

Abstract: Recent studies of natural environments have revealed vast genetic reservoirs of antibiotic resistance (AR) genes. Soil bacteria and human pathogens share AR genes, and AR genes have been discovered in a variety of habitats. However, there is little knowledge about the presence and diversity of AR genes in marine environments and which organisms host AR genes. To address this, we identified the diversity of genes conferring resistance to ampicillin, tetracycline, nitrofurantoin, and sulfadimethoxine in diverse marine environments using functional metagenomics (the cloning and screening of random DNA fragments). Marine environments were host to a diversity of AR-conferring genes. Antibiotic-resistant clones were found at all sites, with 28% of the genes identified as known AR genes (encoding beta-lactamases, bicyclomycin resistance pumps, etc.). However, the majority of AR genes were not previously classified as such but had products similar to proteins such as transport pumps, oxidoreductases, and hydrolases. Furthermore, 44% of the genes conferring antibiotic resistance were found in abundant marine taxa (e.g., Pelagibacter, Prochlorococcus, and Vibrio). Therefore, we uncovered a previously unknown diversity of genes that conferred an AR phenotype among marine environments, which makes the ocean a global reservoir of both clinically relevant and potentially novel AR genes.