Mussels close their shell as a protective strategy and the quantification of this behavioral marker may represent an alarm signal when they are exposed to environmental stressors.In the present study,we investigated t...Mussels close their shell as a protective strategy and the quantification of this behavioral marker may represent an alarm signal when they are exposed to environmental stressors.In the present study,we investigated the ability of the Mediterranean mussel Mytilus galloprovincialis to recover and then the resilience or inertia of valve activity after a pulsing exposition to diverse levels of salinity(5,10,20,and 35 PSU as reference value).The trial simulated an event of drastic and sudden reduction of seawater salinity thus mimicking an event of flash flood from intense rain.Valve gaping and movements were measured in continuous cycle for 10 days using a customized magnetoelectric device which uses Hall sensors.Results showed that under normal conditions of salinity(35 PSU),the general pattern of valve movements was a continuously open state with sporadic spikes indicating a closing motion.At salinity of 5,PSU mussels reacted by closing their valves,leading to a 77%mortality on the 4th day.At salinity of 10,PSU animals were observed with closed valves for the entire duration of the exposure and no mortality occurred,they showed a significant reduction in the valve activity once the reference value of salinity was reestablished.In contrast,salinity of 20 PSU did not trigger a significant behavioral response.Interestingly,there no define rhythms of valve movements were recorded during salinity challenges.展开更多
Objective:To investigate plasmid DNA profiles and the antibiotic resistance of a total of 41 strains of Escherichia coli(E.coli)isolated from seawater and mussel collected from 15 different sampling stations in Sinop,...Objective:To investigate plasmid DNA profiles and the antibiotic resistance of a total of 41 strains of Escherichia coli(E.coli)isolated from seawater and mussel collected from 15 different sampling stations in Sinop,Turkey.Methods:Most probable number technique was used for detection of E.coli.Antibiotic susceptibilities of the isolates were determined by the disc diffusion method.Plasmid DNA of the strains was extracted by the alkaline lyses procedure.Results:According to morphological and physiological properties,it was determined that the isolates belonged to E.coli species.Antibiotic susceptibility of the strains was determined against seven standard drugs using disc diffusion method.All isolates were resistant to bacitracin(100%),novobiocin(100%),ampicillin(12.5%),tetracycline(7.5%),ceftazidime(5%)and imipenem(2.5%),respectively,whereas the strains were susceptible to polymyxin B(100%).The multiple antibiotic resistance values for the strains were found in range from 0.28 to 0.57.In addition,plasmid DNA analyses results confirmed that 22 strains harbored a single or more than two plasmids sized approximately between 24.500 to 1.618 bp.The high-size plasmid(14.700 bp)was observed as common in 21 of all strains.Conclusions:As a result,our study indicated that the presence of antibiotic resistant E.coli strains in seawater and mussel might be potential risk for public health issue.展开更多
基金This study is part of the project“Effects of climate environmental shifts on species,communities and ecosystems,”funded by the Fondazione di Sardegna(2018).
文摘Mussels close their shell as a protective strategy and the quantification of this behavioral marker may represent an alarm signal when they are exposed to environmental stressors.In the present study,we investigated the ability of the Mediterranean mussel Mytilus galloprovincialis to recover and then the resilience or inertia of valve activity after a pulsing exposition to diverse levels of salinity(5,10,20,and 35 PSU as reference value).The trial simulated an event of drastic and sudden reduction of seawater salinity thus mimicking an event of flash flood from intense rain.Valve gaping and movements were measured in continuous cycle for 10 days using a customized magnetoelectric device which uses Hall sensors.Results showed that under normal conditions of salinity(35 PSU),the general pattern of valve movements was a continuously open state with sporadic spikes indicating a closing motion.At salinity of 5,PSU mussels reacted by closing their valves,leading to a 77%mortality on the 4th day.At salinity of 10,PSU animals were observed with closed valves for the entire duration of the exposure and no mortality occurred,they showed a significant reduction in the valve activity once the reference value of salinity was reestablished.In contrast,salinity of 20 PSU did not trigger a significant behavioral response.Interestingly,there no define rhythms of valve movements were recorded during salinity challenges.
文摘Objective:To investigate plasmid DNA profiles and the antibiotic resistance of a total of 41 strains of Escherichia coli(E.coli)isolated from seawater and mussel collected from 15 different sampling stations in Sinop,Turkey.Methods:Most probable number technique was used for detection of E.coli.Antibiotic susceptibilities of the isolates were determined by the disc diffusion method.Plasmid DNA of the strains was extracted by the alkaline lyses procedure.Results:According to morphological and physiological properties,it was determined that the isolates belonged to E.coli species.Antibiotic susceptibility of the strains was determined against seven standard drugs using disc diffusion method.All isolates were resistant to bacitracin(100%),novobiocin(100%),ampicillin(12.5%),tetracycline(7.5%),ceftazidime(5%)and imipenem(2.5%),respectively,whereas the strains were susceptible to polymyxin B(100%).The multiple antibiotic resistance values for the strains were found in range from 0.28 to 0.57.In addition,plasmid DNA analyses results confirmed that 22 strains harbored a single or more than two plasmids sized approximately between 24.500 to 1.618 bp.The high-size plasmid(14.700 bp)was observed as common in 21 of all strains.Conclusions:As a result,our study indicated that the presence of antibiotic resistant E.coli strains in seawater and mussel might be potential risk for public health issue.
