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Papers by Gabriela Giacoboni

Research paper thumbnail of Salmonella enterica Subclinical Infection: Bacteriological, Serological, Pulsed-Field Gel Electrophoresis, and Antimicrobial Resistance Profiles—Longitudinal Study in a Three-Site Farrow-to-Finish Farm

Foodborne Pathogens and Disease, 2009

The aim of this surveillance was to study both Salmonella spp. shedding patterns and the time cou... more The aim of this surveillance was to study both Salmonella spp. shedding patterns and the time course of serological response in farrow-to-finish reared pigs from a subclinically infected farm. Antimicrobial resistance profile, molecular subtyping, and the relationship among the isolates were determined by pulsed-field gel electrophoresis (PFGE). A farrow-to-finish farm of 6000 sows, with a history of Salmonella Typhimurium septicemia, was selected. A longitudinal bacteriological and serological study was conducted in 25 sows before farrowing (M=S1) and in 50 offspring at 21 (M=S2), 35 (M=S3), 65 (M=S4), 86 (M=S5), 128 (M=S6), and 165 (M=S7) days of age. Serum antibodies were tested using Herdcheck Ò Swine Salmonella antibody test kit (Idexx Laboratories, ME). Bacteria were isolated from pooled fecal samples. Suspected isolates were confirmed by conventional biochemical assays, and those identified as Salmonella spp. were serotyped. A variation between seropositive percentages and positive fecal samples was observed. Serologically positive pigs decreased from S1 to S4, and subsequently increased from S4 to S7. The percentages of fecal positive culture increased from M1 to M3, and then declined in M4, increased in M5, and were negative in M6 and M7.

Research paper thumbnail of Thermotolerant Campylobacters in domestic animals in a defined population in Buenos Aires, Argentina

Preventive Veterinary Medicine, 2002

We assessed the prevalence of Campylobacter jejuni in animals in a region of unsatisfied basic ne... more We assessed the prevalence of Campylobacter jejuni in animals in a region of unsatisfied basic needs in the city of Buenos Aires and studied a few risk factors. First we conducted a census to identify all dwellings having pet animals (dogs, cats, and birds). Fecal samples were then taken for isolation and identification of strains. We observed 17% prevalence for dogs (95% CI: 13, 22), 16% for cats (95% CI: 8, 27) and 19% for birds (95% CI: 5, 42). In dogs, the highest prevalences were found in summer and in animals <1 year old; in cats, in autumn and those aged 3-5 years. Strains were identified as C. jejuni biotype II in 70% of isolates. In the population described here, dogs, cats and birds kept in households were potential sources of human Campylobacter infections.

Research paper thumbnail of Isolation of Campylobacter lari from seabirds in Hope Bay, Antarctica

... Gerardo LEOTTA, Germán VIGO and Gabriela GIACOBONI ... These birds could be effective carrier... more ... Gerardo LEOTTA, Germán VIGO and Gabriela GIACOBONI ... These birds could be effective carriers of C. lari as they come into close contact with hu− mans and many other seabird species; for example, they are opportunistic preda− tors of Adelie penguins. ...

Research paper thumbnail of PREDICTIVE MODELS FOR THE SURVIVAL OF CAMPYLOBACTER JEJUNI INOCULATED IN CHICKEN MEAT

Journal of Food Processing and Preservation, 2010

ABSTRACTCampylobacter jejuni is an emerging pathogen that is becoming more relevant due to the hi... more ABSTRACTCampylobacter jejuni is an emerging pathogen that is becoming more relevant due to the high percentage of isolations found in raw or undercooked poultry products. The objective of the present work was to analyze and to model mathematically the effect of storage temperature (+4 and −2C), potassium sorbate concentration (0, 500 and 1,000 ppm) and packaging in plastic films of different gas permeabilities (low and high gas permeability, polyethylene and EVA SARAN EVA) on the survival of C. jejuni inoculated into chicken meat. Different models (linear, Gompertz and Weibull equation) were applied to experimental data, obtaining the best fit with the Weibull model. Among analyzed factors, storage temperature (+4 and −2C) was the most effective factor to inhibit growth of C. jejuni in chicken meat that reduce microbial counts between 3 and 4 logarithmic cycles. However, at −2C, the inhibitory effect was more successful. Potassium sorbate and packaging in different permeability films did not show inhibitory effect on C. jejuni.Campylobacter jejuni is an emerging pathogen that is becoming more relevant due to the high percentage of isolations found in raw or undercooked poultry products. The objective of the present work was to analyze and to model mathematically the effect of storage temperature (+4 and −2C), potassium sorbate concentration (0, 500 and 1,000 ppm) and packaging in plastic films of different gas permeabilities (low and high gas permeability, polyethylene and EVA SARAN EVA) on the survival of C. jejuni inoculated into chicken meat. Different models (linear, Gompertz and Weibull equation) were applied to experimental data, obtaining the best fit with the Weibull model. Among analyzed factors, storage temperature (+4 and −2C) was the most effective factor to inhibit growth of C. jejuni in chicken meat that reduce microbial counts between 3 and 4 logarithmic cycles. However, at −2C, the inhibitory effect was more successful. Potassium sorbate and packaging in different permeability films did not show inhibitory effect on C. jejuni.PRACTICAL APPLICATIONSThe results of this study suggest that potassium sorbate and packaging films did not show inhibitory effect on Campylobacter jejuni inoculated in chicken meat. Storage temperature (+4 and −2C) is the most important factor in controlling the growth of C. jejuni in chicken meat.The results of this study suggest that potassium sorbate and packaging films did not show inhibitory effect on Campylobacter jejuni inoculated in chicken meat. Storage temperature (+4 and −2C) is the most important factor in controlling the growth of C. jejuni in chicken meat.

Research paper thumbnail of Salmonella enterica Subclinical Infection: Bacteriological, Serological, Pulsed-Field Gel Electrophoresis, and Antimicrobial Resistance Profiles—Longitudinal Study in a Three-Site Farrow-to-Finish Farm

Foodborne Pathogens and Disease, 2009

The aim of this surveillance was to study both Salmonella spp. shedding patterns and the time cou... more The aim of this surveillance was to study both Salmonella spp. shedding patterns and the time course of serological response in farrow-to-finish reared pigs from a subclinically infected farm. Antimicrobial resistance profile, molecular subtyping, and the relationship among the isolates were determined by pulsed-field gel electrophoresis (PFGE). A farrow-to-finish farm of 6000 sows, with a history of Salmonella Typhimurium septicemia, was selected. A longitudinal bacteriological and serological study was conducted in 25 sows before farrowing (M=S1) and in 50 offspring at 21 (M=S2), 35 (M=S3), 65 (M=S4), 86 (M=S5), 128 (M=S6), and 165 (M=S7) days of age. Serum antibodies were tested using Herdcheck Ò Swine Salmonella antibody test kit (Idexx Laboratories, ME). Bacteria were isolated from pooled fecal samples. Suspected isolates were confirmed by conventional biochemical assays, and those identified as Salmonella spp. were serotyped. A variation between seropositive percentages and positive fecal samples was observed. Serologically positive pigs decreased from S1 to S4, and subsequently increased from S4 to S7. The percentages of fecal positive culture increased from M1 to M3, and then declined in M4, increased in M5, and were negative in M6 and M7.

Research paper thumbnail of Thermotolerant Campylobacters in domestic animals in a defined population in Buenos Aires, Argentina

Preventive Veterinary Medicine, 2002

We assessed the prevalence of Campylobacter jejuni in animals in a region of unsatisfied basic ne... more We assessed the prevalence of Campylobacter jejuni in animals in a region of unsatisfied basic needs in the city of Buenos Aires and studied a few risk factors. First we conducted a census to identify all dwellings having pet animals (dogs, cats, and birds). Fecal samples were then taken for isolation and identification of strains. We observed 17% prevalence for dogs (95% CI: 13, 22), 16% for cats (95% CI: 8, 27) and 19% for birds (95% CI: 5, 42). In dogs, the highest prevalences were found in summer and in animals <1 year old; in cats, in autumn and those aged 3-5 years. Strains were identified as C. jejuni biotype II in 70% of isolates. In the population described here, dogs, cats and birds kept in households were potential sources of human Campylobacter infections.

Research paper thumbnail of Isolation of Campylobacter lari from seabirds in Hope Bay, Antarctica

... Gerardo LEOTTA, Germán VIGO and Gabriela GIACOBONI ... These birds could be effective carrier... more ... Gerardo LEOTTA, Germán VIGO and Gabriela GIACOBONI ... These birds could be effective carriers of C. lari as they come into close contact with hu− mans and many other seabird species; for example, they are opportunistic preda− tors of Adelie penguins. ...

Research paper thumbnail of PREDICTIVE MODELS FOR THE SURVIVAL OF CAMPYLOBACTER JEJUNI INOCULATED IN CHICKEN MEAT

Journal of Food Processing and Preservation, 2010

ABSTRACTCampylobacter jejuni is an emerging pathogen that is becoming more relevant due to the hi... more ABSTRACTCampylobacter jejuni is an emerging pathogen that is becoming more relevant due to the high percentage of isolations found in raw or undercooked poultry products. The objective of the present work was to analyze and to model mathematically the effect of storage temperature (+4 and −2C), potassium sorbate concentration (0, 500 and 1,000 ppm) and packaging in plastic films of different gas permeabilities (low and high gas permeability, polyethylene and EVA SARAN EVA) on the survival of C. jejuni inoculated into chicken meat. Different models (linear, Gompertz and Weibull equation) were applied to experimental data, obtaining the best fit with the Weibull model. Among analyzed factors, storage temperature (+4 and −2C) was the most effective factor to inhibit growth of C. jejuni in chicken meat that reduce microbial counts between 3 and 4 logarithmic cycles. However, at −2C, the inhibitory effect was more successful. Potassium sorbate and packaging in different permeability films did not show inhibitory effect on C. jejuni.Campylobacter jejuni is an emerging pathogen that is becoming more relevant due to the high percentage of isolations found in raw or undercooked poultry products. The objective of the present work was to analyze and to model mathematically the effect of storage temperature (+4 and −2C), potassium sorbate concentration (0, 500 and 1,000 ppm) and packaging in plastic films of different gas permeabilities (low and high gas permeability, polyethylene and EVA SARAN EVA) on the survival of C. jejuni inoculated into chicken meat. Different models (linear, Gompertz and Weibull equation) were applied to experimental data, obtaining the best fit with the Weibull model. Among analyzed factors, storage temperature (+4 and −2C) was the most effective factor to inhibit growth of C. jejuni in chicken meat that reduce microbial counts between 3 and 4 logarithmic cycles. However, at −2C, the inhibitory effect was more successful. Potassium sorbate and packaging in different permeability films did not show inhibitory effect on C. jejuni.PRACTICAL APPLICATIONSThe results of this study suggest that potassium sorbate and packaging films did not show inhibitory effect on Campylobacter jejuni inoculated in chicken meat. Storage temperature (+4 and −2C) is the most important factor in controlling the growth of C. jejuni in chicken meat.The results of this study suggest that potassium sorbate and packaging films did not show inhibitory effect on Campylobacter jejuni inoculated in chicken meat. Storage temperature (+4 and −2C) is the most important factor in controlling the growth of C. jejuni in chicken meat.