Ayesha
Detection Of Hazardous Organism In Raw And Pasteurized Milk With Particular Reference To 3Enterobacteriaceae - 2010
The present study was carried out to detect the hazardous organisms in raw milk from public health point of view. In total one hundred twenty (120) milk samples were collected from milk retail shops in and around Lahore. Out of these 120, one hundred samples were of raw milk and rests of the twenty samples were of pasteurized milk. Their microbiological quality was studied by performing standard plate count (SPC), coliform count and identification of hazardous bacteria belonging to the family Enterobacteriaceae. The micro flora of milk was also studied for the prevalence of multiple drug resistant (MDR) bacteria.
Milk supplied in Lahore city was found to have poor microbiological quality. Bacterial load was determined by SPC and coliform count. The standard plate count (S.P.C) of the raw milk ranged from 4.2x106 to 7.7xl07 c.f.u/ml. The coliform counts ranged from 3.4x 104 c.f.u /ml to 6.9x105 /ml. A total of 81 isolates were identified from raw milk samples. These included Yersinia (3 strains), Klebsiella (16 strains), Escherichia coli (14 strains), Enterobacter (11 strains), Shigella (3 strains), Salmonella (19 strains) and' Proteus (15 strains).The standard plate count for pasteurized milk ranged from 1.45x104 c.f.u/ml to 3.8x 105 c.f.u/ml. The minimum and maximum coliform count was 7.2x102 to 8.4xl03 c.f.u/ml respectively for pasteurized. All samples were outside the international standard for coliform bacteria. A total of 13 isolates were identified from pasteurized milk samples. These included Yersinia (2 strains), Klebsiella (1 strains), Escherichia coli (6 strains), Enterobacter (2 strains), Shigella (1 strains) and Proteus (1 strains).
All the isolates showed multiple drug resistance to various commonly used antibiotics in veterinary practices. Escherichia coli were resistant to all antibiotics used except Gentamicin (10µg). Enterobacter was sensitive to all the antibiotics used except to Ampicillin (10µg). Shigella was sensitive to Gentamicin (10µg), Kanamycin (30µg), Choloramphenicol( 25µg), but showed resistance to Ampicillin (10µg), Oxytetracycline ( 25µg), Streptomycin (10 µg), Pencillin (10 µg) and Tribrissin (25µg)., Salmonella was resistanct to Ampicillin (10µg), Oxytetracycline ( 25µg), Streptomycin (10 µg), Pencillin (10 µg) and Tribrissin (25µg). But sensitive to Gentamicin (10µg). .All the isolates showed greatest resistance to Penicillin (10 ug.) whereas, most of the isolates were sensitive to Gentamycin, Kanamycin and Chloramphenicol.
Finally, it is recommended that the members of the public should always boil raw milk before consumption because of their microbial content. Therefore, it is highly recommended that hygienic practices and regulations, such as on-site pasteurization and implementation of HACCP following established standards, should be introduced to facilitate the production of raw milk of high quality and safety.
Department of Microbiology
1219,T
Detection Of Hazardous Organism In Raw And Pasteurized Milk With Particular Reference To 3Enterobacteriaceae - 2010
The present study was carried out to detect the hazardous organisms in raw milk from public health point of view. In total one hundred twenty (120) milk samples were collected from milk retail shops in and around Lahore. Out of these 120, one hundred samples were of raw milk and rests of the twenty samples were of pasteurized milk. Their microbiological quality was studied by performing standard plate count (SPC), coliform count and identification of hazardous bacteria belonging to the family Enterobacteriaceae. The micro flora of milk was also studied for the prevalence of multiple drug resistant (MDR) bacteria.
Milk supplied in Lahore city was found to have poor microbiological quality. Bacterial load was determined by SPC and coliform count. The standard plate count (S.P.C) of the raw milk ranged from 4.2x106 to 7.7xl07 c.f.u/ml. The coliform counts ranged from 3.4x 104 c.f.u /ml to 6.9x105 /ml. A total of 81 isolates were identified from raw milk samples. These included Yersinia (3 strains), Klebsiella (16 strains), Escherichia coli (14 strains), Enterobacter (11 strains), Shigella (3 strains), Salmonella (19 strains) and' Proteus (15 strains).The standard plate count for pasteurized milk ranged from 1.45x104 c.f.u/ml to 3.8x 105 c.f.u/ml. The minimum and maximum coliform count was 7.2x102 to 8.4xl03 c.f.u/ml respectively for pasteurized. All samples were outside the international standard for coliform bacteria. A total of 13 isolates were identified from pasteurized milk samples. These included Yersinia (2 strains), Klebsiella (1 strains), Escherichia coli (6 strains), Enterobacter (2 strains), Shigella (1 strains) and Proteus (1 strains).
All the isolates showed multiple drug resistance to various commonly used antibiotics in veterinary practices. Escherichia coli were resistant to all antibiotics used except Gentamicin (10µg). Enterobacter was sensitive to all the antibiotics used except to Ampicillin (10µg). Shigella was sensitive to Gentamicin (10µg), Kanamycin (30µg), Choloramphenicol( 25µg), but showed resistance to Ampicillin (10µg), Oxytetracycline ( 25µg), Streptomycin (10 µg), Pencillin (10 µg) and Tribrissin (25µg)., Salmonella was resistanct to Ampicillin (10µg), Oxytetracycline ( 25µg), Streptomycin (10 µg), Pencillin (10 µg) and Tribrissin (25µg). But sensitive to Gentamicin (10µg). .All the isolates showed greatest resistance to Penicillin (10 ug.) whereas, most of the isolates were sensitive to Gentamycin, Kanamycin and Chloramphenicol.
Finally, it is recommended that the members of the public should always boil raw milk before consumption because of their microbial content. Therefore, it is highly recommended that hygienic practices and regulations, such as on-site pasteurization and implementation of HACCP following established standards, should be introduced to facilitate the production of raw milk of high quality and safety.
Department of Microbiology
1219,T