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1. Anti-Herpetic Activity of Killer Peptide (KP): An In Vitro Study.

Author

Sala, Arianna, Ricchi, Francesco, Giovati, Laura, Conti, Stefania, Ciociola, Tecla, and Cermelli, Claudio

Subjects
ANTIMICROBIAL peptides, PEPTIDES, HUMAN herpesvirus 2, DRUG prices, DRUG resistance, ANTIVIRAL agents
Abstract

Antimicrobial peptides represent a promising alternative to traditional drugs in relation to cost, toxicity, and, primarily, the growing problem of drug resistance. Here, we report on the activity against HSV-1 and HSV-2 of a previously described wide-spectrum synthetic decapeptide, Killer Peptide (KP). As determined by plaque reduction assays, treatment with KP at 100 μg/mL resulted in a reduction in the viral yield titer of 3.5 Logs for HSV-1 and 4.1 Logs for HSV-2. Further evaluation of KP antiviral activity focused on the early stages of the virus replicative cycle, including the determination of the residual infectivity of viral suspensions treated with KP. A direct effect of the peptide on viral particles impairing virus absorption and penetration was shown. The toxicity profile proved to be extremely good, with a selectivity index of 29.6 for HSV-1 and 156 for HSV-2. KP was also active against acyclovir (ACV)-resistant HSV isolates, while HSV subcultures in the presence of sub-inhibitory doses of KP did not lead to the emergence of resistant strains. Finally, the antiviral action of KP proved to be synergistic with that of ACV. Overall, these results demonstrate that KP could represent an interesting addition/alternative to acyclovir for antiviral treatment. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Activity of Synthetic Peptide KP and Its Derivatives against Biofilm-Producing Escherichia coli Strains Resistant to Cephalosporins.

Author

Artesani, Lorenza, Ciociola, Tecla, Vismarra, Alice, Bacci, Cristina, Conti, Stefania, and Giovati, Laura

Subjects
ESCHERICHIA coli, ANTIMICROBIAL peptides, DRUG resistance in bacteria, PEPTIDES, LASER microscopy, PEPTIDE antibiotics
Abstract

Bacterial resistance to β-lactam antibiotics, particularly new generation cephalosporins, is a major public health concern. In Escherichia coli, resistance to these antibiotics is mainly mediated by extended-spectrum β-lactamases (ESBL), which complicates a range of health-threatening infections. These infections may also be biofilm-related, making them more difficult to treat because of the higher tolerance to conventional antibiotics and the host immune response. In this study, we tested as potential new drug candidates against biofilm-forming ESBL-producing E. coli four antimicrobial peptides previously shown to have antifungal properties. The peptides proved to be active in vitro at micromolar concentrations against both sensitive and ESBL-producing E. coli strains, effectively killing planktonic cells and inhibiting biofilm formation. Quantitative fluorescence intensity analysis of three-dimensional reconstructed confocal laser scanning microscopy (CLSM) images of mature biofilm treated with the most active peptide showed significant eradication and a reduction in viable bacteria, while scanning electron microscopy (SEM) revealed gross morphological alterations in treated bacteria. The screening of the investigated peptides for antibacterial and antibiofilm activity led to the selection of a leading candidate to be further studied for developing new antimicrobial drugs as an alternative treatment against microbial infections, primarily associated with biofilms. [ABSTRACT FROM AUTHOR]

Published
2024
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15. The activity of a mammalian proline-rich peptide against Gram-negative bacteria, including drug-resistant strains, relies on a nonmembranolytic mode of action

Author

Ciociola,Tecla, Giovati,Laura, Giovannelli,Angela, Conti,Stefania, Castagnola,Massimo, Vitali,Alberto, Ciociola,Tecla, Giovati,Laura, Giovannelli,Angela, Conti,Stefania, Castagnola,Massimo, and Vitali,Alberto

Abstract

Tecla Ciociola,1 Laura Giovati,1 Angela Giovannelli,2 Stefania Conti,1 Massimo Castagnola,2,3 Alberto Vitali3 1Department of Medicine and Surgery, University of Parma, Parma, 2Institute of Biochemistry and Clinical Biochemistry, Catholic University, Rome, 3Institute for the Chemistry of Molecular Recognition, C.N.R., c/o Institute of Biochemistry and Clinical Biochemistry, Catholic University, Rome, Italy Background: A peptide of 2,733 Da named SP-E, previously isolated from pig saliva and already described for its antifungal activity and absence of toxicity against mammalian cells, is characterized by a high content of proline residues (70% of entire sequence), that confer structural features probably related to peptide activity. Purpose: The aim of this study was to evaluate the activity of SP-E against Gram-negative bacteria, including drug-resistant clinical isolates. Methods: SP-E and shorter fragments of the same peptide were tested in vitro against the selected bacteria by colony forming unit assays. Scanning electron microscopy and confocal microscopy were also applied. SP-E potential therapeutic activity was evaluated in vivo in a Galleria mellonella model of bacterial infection. Results: SP-E proved to be active against the tested bacteria with EC50 values in the micromolar range. Though maintaining antibacterial properties, the shorter peptides showed lower activity in respect to the parental molecule. Kinetics of killing action and nonmembranolytic internalization within Escherichia coli and Pseudomonas aeruginosa cells strongly suggested a cytosolic mechanism of action involving one or more intracellular molecular targets. A single injection of SP-E exerted a therapeutic effect in G. mellonella larvae infected with P. aeruginosa. Conclusion: The biological properties of SP-E strongly back this peptide as a new promising multitasking antimicrobial molecule. Keywords: antimicrobial peptide, proline-rich peptides, drug-resistant bacteria, confocal microsco

Published
2018

19. Novel Activity of a Synthetic Decapeptide Against Toxoplasma gondii Tachyzoites

Author

Giovati, Laura, primary, Santinoli, Claudia, additional, Mangia, Carlo, additional, Vismarra, Alice, additional, Belletti, Silvana, additional, D’Adda, Tiziana, additional, Fumarola, Claudia, additional, Ciociola, Tecla, additional, Bacci, Cristina, additional, Magliani, Walter, additional, Polonelli, Luciano, additional, Conti, Stefania, additional, and Kramer, Laura H., additional

Published
2018
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21. Discovering a new class of antifungal agents that selectively inhibits microbial carbonic anhydrases

Author

Annunziato, Giannamaria, primary, Giovati, Laura, additional, Angeli, Andrea, additional, Pavone, Marialaura, additional, Del Prete, Sonia, additional, Pieroni, Marco, additional, Capasso, Clemente, additional, Bruno, Agostino, additional, Conti, Stefania, additional, Magliani, Walter, additional, Supuran, Claudiu T., additional, and Costantino, Gabriele, additional

Published
2018
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23. A Naturally Occurring Antibody Fragment Neutralizes Infectivity of Diverse Infectious Agents

Author

Polonelli, Luciano, primary, Ciociola, Tecla, additional, Elviri, Lisa, additional, Zanello, Pier Paolo, additional, Giovati, Laura, additional, Arruda, Denise C., additional, Muñoz, Julián E., additional, Mortara, Renato A., additional, Morace, Giulia, additional, Borghi, Elisa, additional, Galati, Serena, additional, Marin, Oriano, additional, Casoli, Claudio, additional, Pilotti, Elisabetta, additional, Ronzi, Paola, additional, Travassos, Luiz R., additional, Magliani, Walter, additional, and Conti, Stefania, additional

Published
2016
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25. Dissecting the Structure-Function Relationship of a Fungicidal Peptide Derived from the Constant Region of Human Immunoglobulins

Author

Ciociola, Tecla, primary, Pertinhez, Thelma A., additional, Giovati, Laura, additional, Sperindè, Martina, additional, Magliani, Walter, additional, Ferrari, Elena, additional, Gatti, Rita, additional, D'Adda, Tiziana, additional, Spisni, Alberto, additional, Conti, Stefania, additional, and Polonelli, Luciano, additional

Published
2016
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28. Studies on the immunization against aflatoxins

Author

Giovati, Laura

Subjects
Milk, Aflatoxins, Aflatoxicoses, MED/07, Vaccine
Abstract

Aflatossine (AF), metaboliti secondari tossici prodotti principalmente da ceppi dei funghi ubiquitari Aspergillus flavus e A. parasiticus, sono le più importanti micotossine di interesse medico (AFB1, AFB2, AFG1, AFG2). In seguito all’ingestione di alimenti contaminati, AFB1 e AFB2, in particolare, sono in parte assorbite e trasportate al fegato dove vengono convertite nei rispettivi metaboliti idrossilati AFM1 ed AFM2. Attraverso il torrente circolatorio, AFM1 e AFM2 possono raggiungere altri organi e tessuti ed essere escrete attraverso la via biliare, urinaria o mammaria (processo di carry-over). AFB1, la forma prevalente tra le AF, e AFM1 sono state classificate dall’ International Agency for Research on Cancer (IARC) come cancerogeni di gruppo 1 e di gruppo 2B, rispettivamente, per l’uomo. Al fine di ridurre il rischio di esposizione per l’uomo e gli animali, i livelli massimi di AF tollerati in alimenti e mangimi sono stati variamente regolamentati in molti paesi. In questo studio, è stato verificato il potenziale vaccinale di AFB1-1(O-carbossimetil) ossima (AFB1-ox), chimicamente derivata da AFB1, coniugata ad emocianina (KLH), per la prevenzione del carry-over in vacche da latte intossicate con AFB1. Comparativamente a AFB1, AFB1-ox è stata dimostrata atossica e non mutagena in vitro nei confronti di cellule di epatocarcinoma umano e ceppi di Salmonella typhimurium, rispettivamente, e definita Anaflatossina B1 (AnAFB1). In seguito ad immunizzazione sistemica di vacche da latte con il coniugato AnAFB1-KLH, è stata rilevata l’induzione di anticorpi (IgG) sierici specifici per AFB1, presentanti reattività crociata decrescente con AFG1, AFB2 e AFG2, in grado di prevenire l’escrezione di AFM1 nel latte di vacche sottoposte a ripetuti cicli di ingestione di mangime contaminato da quantità note di AFB1. La vaccinazione di lattifere con AnAFB1-KLH potrebbe rappresentare la prova di concetto per la soluzione del problema aflatossicosi M1 da latte e prodotti derivati, quali formaggi e yogurt, nell’uomo. Aflatoxins (AF), toxic secondary metabolites mainly produced by strains of Aspergillus flavus and A. parasiticus, represent the most important mycotoxins of medical interest (AFB1, AFB2, AFG1, AFG2). Once ingested, AFB1 and AFB2, in particular, are partially adsorbed and transported to the liver where they are metabolized into the hydroxy derivates AFM1 and AFM2 which, through the bloodstream, may reach other tissues and organs and be excreted, via bile, urinary and mammary pathways (carry-over process). AFB1, the most prevalent and toxic among AF, and AFM1 have been included by the International Agency for Research on Cancer (IARC) in group 1 and 2B human carcinogens, respectively. To reduce human and animal exposure, AF maximum levels in foods and feeds have been variously regulated in many countries. In this study, the vaccinal potential of the AFB1 derivate AFB1-1(O-carboxymethyl) oxime (AFB1-ox) conjugated to keyhole limpet hemocyanin (KLH) for carry-over prevention in dairy cattles intoxycated with AFB1 is reported. In comparison with AFB1, AFB1-ox has proven to be nontoxic in vitro to human hepatocarcinomas cells and devoid of mutagenic activity in Salmonella typhimurium tester strains, being therefore defined as anaflatoxin B1 (AnAFB1). AnAFB1-KLH proved to be immunogenic in cows following systemic administration, inducing specific anti-AFB1 IgG serum antibodies decreasingly cross reacting with AFG1, AFB2 and AFG2. The elicited anti-AF Abs were able to overcome the excretion of AFM1 into the milk of cattles repeatedly fed with determined amounts of AFB1. Vaccination of dairy cattle with AnAFB1-KLH may represent the prove of concept for the solution of the public hazard constituted by milk and milk products, such as cheese an yoghurt, contaminated with AFM1.

Published
2010

29. Yeast Killer Toxin-Like Candidacidal Ab6 Antibodies Elicited through the Manipulation of the Idiotypic Cascade

Author

Polonelli, Luciano, primary, Beninati, Concetta, additional, Teti, Giuseppe, additional, Felici, Franco, additional, Ciociola, Tecla, additional, Giovati, Laura, additional, Sperindè, Martina, additional, Passo, Carla Lo, additional, Pernice, Ida, additional, Domina, Maria, additional, Arigò, Milena, additional, Papasergi, Salvatore, additional, Mancuso, Giuseppe, additional, Conti, Stefania, additional, and Magliani, Walter, additional

Published
2014
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32. Vaccination of Lactating Dairy Cows for the Prevention of Aflatoxin B1 Carry Over in Milk

Author

Polonelli, Luciano, primary, Giovati, Laura, additional, Magliani, Walter, additional, Conti, Stefania, additional, Sforza, Stefano, additional, Calabretta, Alessandro, additional, Casoli, Claudio, additional, Ronzi, Paola, additional, Grilli, Ester, additional, Gallo, Antonio, additional, Masoero, Francesco, additional, and Piva, Gianfranco, additional

Published
2011
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33. Vaccination of Heifers with Anaflatoxin Improves the Reduction of Aflatoxin B1 Carry Over in Milk of Lactating Dairy Cows.

Author

Giovati, Laura, Gallo, Antonio, Masoero, Francesco, Cerioli, Carla, Ciociola, Tecla, Conti, Stefania, Magliani, Walter, and Polonelli, Luciano

Subjects
*CATTLE vaccination, *AFLATOXINS, *LACTATION in cattle, *COW physiology, *HEMOCYANIN, *DIPHTHERIA vaccines
Abstract

It was previously reported that injection of anaflatoxin B1 (AnAFB1) conjugated to keyhole limpet hemocyanin (KLH), together with Freund's adjuvant, was effective in inducing in cows a long lasting titer of anti-aflatoxin B1 (AFB1) antibodies (Abs), cross-reacting with other aflatoxins, which were able to hinder, proportionally to their titer, the secretion of aflatoxin M1 (AFM1) into the milk of cows continuously fed with AFB1. According to anti-AFB1 Ab titer, 50% of the vaccinated cows were recognized as high responder animals. In an attempt to prepare a more effective formulation for vaccination of cows, it was compared the immunogenicity, in Holstein Friesian heifers, of AnAFB1 covalently conjugated to KLH or to recombinant diphtheria toxin (CRM197) molecules, and injected together with various adjuvants. This study demonstrated that injection of AnAFB1 conjugated to KLH and mixed with complete (priming) and incomplete Freund's adjuvant (boosters), as in the previous schedule of immunization, was the most effective regimen for inducing Ab responses against AFB1, although pre-calving administration could increase the effectiveness of vaccination, resulting in 100% high responder animals. After one booster dose at the beginning of the milk production cycle, anti-AFB1 Ab titers were comparable to those recorded at the end of the immunization schedule, and proved to be effective in reducing significantly AFB1 carry over, as AFM1, from feed to milk. Pre-calving vaccination of dairy heifers with conjugated AnAFB1, adjuvated with complete and incomplete Freund's adjuvant, may represent the most effective tool for preventing the public health hazard constituted by milk and cheese contaminated with aflatoxins. [ABSTRACT FROM AUTHOR]

Published
2014
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34. Vaccination of Lactating Dairy Cows for the Prevention of Aflatoxin B1 Carry Over in Milk.

Author

Polonelli, Luciano, Giovati, Laura, Magliani, Walter, Conti, Stefania, Sforza, Stefano, Calabretta, Alessandro, Casoli, Claudio, Ronzi, Paola, Grilli, Ester, Gallo, Antonio, Masoero, Francesco, and Piva, Gianfranco

Subjects
*FEMALE livestock, *VACCINATION, *PREVENTION of communicable diseases, *SALMONELLA, *ENTEROBACTERIACEAE, *IMMUNIZATION, *IMMUNOGLOBULIN G, *SALMONELLA typhimurium
Abstract

The potential of anaflatoxin B1 (AnAFB1) conjugated to keyhole limpet hemocyanin (KLH) as a vaccine (AnAFB1-KLH) in controlling the carry over of the aflatoxin B1 (AFB1) metabolite aflatoxin M1 (AFM1) in cow milk is reported. AFB1 is the most carcinogenic compound in food and foodstuffs amongst aflatoxins (AFs). AnAFB1 is AFB1 chemically modified as AFB1-1(O-carboxymethyl) oxime. In comparison to AFB1, AnAFB1 has proven to be non-toxic in vitro to human hepatocarcinoma cells and non mutagenic to Salmonella typhimurium strains. AnAFB1-KLH was used for immunization of cows proving to induce a long lasting titer of anti-AFB1 IgG antibodies (Abs) which were cross reactive with AFB1, AFG1, and AFG2. The elicited anti-AFB1 Abs were able to hinder the secretion of AFM1 into the milk of cows continuously fed with AFB1. Vaccination of lactating animals with conjugated AnAFB1 may represent a solution to the public hazard constituted by milk and cheese contaminated with AFs. [ABSTRACT FROM AUTHOR]

Published
2011
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35. Screening of a Saccharomyces cerevisiae nonessential gene deletion collection for altered susceptibility to a killer peptide.

Author

Conti S, Magliani W, Giovati L, Libri I, Maffei DL, Salati A, and Polonelli L

Subjects
Killer Factors, Yeast, Microbial Sensitivity Tests, Mutation, Peptides chemistry, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Saccharomyces cerevisiae Proteins metabolism, Gene Deletion, Mycotoxins chemistry, Peptides chemical synthesis, Peptides pharmacology, Saccharomyces cerevisiae drug effects, Saccharomyces cerevisiae Proteins genetics
Abstract

Approximately 4,800 Saccharomyces cerevisiae mutants deleted for nonessential genes were screened for alterations in susceptibility to a synthetic killer peptide (KP). None of the tested strains, including mutants resistant to conventional antifungal drugs, showed increased or decreased susceptibility to KP in comparison with the parental strain. The results may reflect the peculiar mechanism of action of KP and claim the possible avoidance of vital resistant mutants.

Published
2008

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