Methicillin Resistant Staphylococcus aureus (MRSA) causing
surgical site infections is one of the most common nosocomial infections
affecting post-surgery patients. Vancomycin is the recommended treatment
with MRSA-resistance breakpoint for minimum inhibition concentration (MIC)
of 2 ug/mL where the pathogen can be considered as susceptible. Here, we
describe the MIC of vancomycin against our MRSA isolates. Retrospective
data of MRSA positive cultures from post-surgical patients who were admitted
to the Clinical Training Centre Sungai Buloh public section from 2016-2017
with documented MIC to vancomycin were analyzed. The specimens consist
of pus swabs, mediastinal fluid, sternal bone, and tissue. A total of 29 MRSA
were isolated from 11 patients. There were 19, 3, 3 and 4 MRSA with
vancomycin’s MIC (ug/mL) of 0.5, 1, 1.5 and 2 respectively. The MRSA with
MIC of 2 ug/mL were observed from two different patients with one of them
showing MIC of 0.5 ug/mL which grew from wound swabs to 2.0 ug/mL which
grew from sternal bone and mediastinal fluid isolates. Vancomycin reduced
susceptibility MRSA has been observed in our clinical training centre with a
1.1% incidence. Identification of possible risk factors and follow up of
outcomes is required to fully elucidate the importance of this occurrence.
Serving raw oysters with lemon juice is a delicacy in many restaurants in
Malaysia. Oysters (Crassostrea virginica) live in the seacoast and they share the same
environment as Vibrio parahaemolyticus. Consumption of raw oysters contaminated with V.
parahaemolyticus can lead to severe gastroenteritis. A study was performed to determine
whether lemon (Citrus limon) juice is able to inhibit the growth of V. parahaemolyticus after
being inoculated in raw oysters. Methods: Frozen oysters bought from a local supplier
weighing 6 g each were minced and placed in two bottles using sterile technique.
Approximately 1 ml of 107 CFU of V. parahaemolyticus (ATCC strain 17802) was added and
mixed in both bottles. The mixture was treated with 1 ml of lemon juice in only one of the
bottles and the other bottle served as a control. At every 30 s intervals for 2 min, 1 g of the
sample was taken for enumeration of viable cells onto thiosulphate citrate bile salt sucrose
(TCBS). Results: After 30 s of treatment with the lemon juice, it was observed that the
number of colonies in the treated samples reduced from 7 Log to 3 Log. Subsequently, no
viable V. parahaemolyticus was seen. It was also observed that there were 3 Log reductions
of V. parahaemolyticus after 30 s in untreated samples, however the number of colonies
remained stable until the end of the experiment. Conclusion: This study therefore shows
that lemon juice has some antimicrobial effect on V. parahaemolyticus in raw oysters.
Introduction: Consuming half-boiled eggs during breakfast is popular among Malaysians. The eggs are usually prepared by submerging them in freshly boiled water for about 20 minutes duration. As chickens have the likelihood of harbouring Salmonella enterica Serovar Enteritidis in their eggs, it is feared that consumption of half-boiled eggs contaminated with S. Enteritidis could lead to gastroenteritis. Hence, this study was carried out to determine the optimum time required for boiled water to kill S. Enteritidis in half-boiled eggs. Methods: Grade C chicken eggs (average weight 54.5 g) were obtained from a local sundry shop and were confirmed to be Salmonella-free prior to the experiment. Fifteen eggs that were previously spiked with 106 colony-forming units (CFU) of S. Enteritidis were completely submerged into freshly-boiled water (≈100ºC) for a maximum of 20 min. Positive controls consisted of eggs that were inoculated but were not treated. At every 5 min interval, three eggs were taken out and checked for presence of viable S. Enteritidis on MacConkey agar, and the respective water temperature was recorded. Results: Results of two independent trials showed that after 10 min of submerging the eggs in the hot water, there were an average of 3 log reductions in the CFU of S. Enteritidis but after 15 min, no viable S. Enteritidis was detected. Conclusion: A half-boiled egg should be prepared by submerging it in freshly boiled water for at least 15 min to ensure that it is safe to be consumed.
Serving raw oysters with lemon juice is a delicacy in many restaurants in
Malaysia. Oysters (Crassostrea virginica) live in the seacoast and they share the same
environment as Vibrio parahaemolyticus. Consumption of raw oysters contaminated with V.
parahaemolyticus can lead to severe gastroenteritis. A study was performed to determine
whether lemon (Citrus limon) juice is able to inhibit the growth of V. parahaemolyticus after
being inoculated in raw oysters. Methods: Frozen oysters bought from a local supplier
weighing 6 g each were minced and placed in two bottles using sterile technique.
Approximately 1 ml of 107 CFU of V. parahaemolyticus (ATCC strain 17802) was added and
mixed in both bottles. The mixture was treated with 1 ml of lemon juice in only one of the
bottles and the other bottle served as a control. At every 30 s intervals for 2 min, 1 g of the
sample was taken for enumeration of viable cells onto thiosulphate citrate bile salt sucrose
(TCBS). Results: After 30 s of treatment with the lemon juice, it was observed that the
number of colonies in the treated samples reduced from 7 Log to 3 Log. Subsequently, no
viable V. parahaemolyticus was seen. It was also observed that there were 3 Log reductions
of V. parahaemolyticus after 30 s in untreated samples, however the number of colonies
remained stable until the end of the experiment. Conclusion: This study therefore shows
that lemon juice has some antimicrobial effect on V. parahaemolyticus in raw oysters.