The national microbiology surveillance programme for 2003 involved the surveillance of four foods (Table 1). In previous years the surveillance programme primarily involved collaboration between the Food Safety Authority of Ireland (FSAI) and the ten health boards (HBs); however, during 2003 collaboration also took place with the Department of Communications, Marine and Natural Resources (DCMNR) and the Department of Agriculture and Food (DAF).

^¡ This survey was undertaken as part of the EU Co-ordinated Programme for the Official Control of Foodstuffs 2003 ⁽¹⁾

Microbiological Quality/Safety of Pre-Packed Cooked Sliced Ham

This survey investigated the microbiological quality (ACC and Enterobacteriaceae) and the microbiological safety (Listeria monocytogenes) of pre-packed cooked sliced ham from retail premises. All samples were cooked, sliced and pre-packed in processing plants.

Applying the national microbiology guidelines for ready-to-eat foods ⁽²⁾ to the results of this survey found that:

·               13% (79/618) of samples were unsatisfactory for ACC and 4% (24/615) were unsatisfactory for Enterobacteriaceae. These results clearly highlight the need for more emphasis to be placed on control strategies (e.g. process control, good hygiene practices and temperature control).  This study did not determine the stage in the food chain (e.g. manufacturing, distribution, retail) where the microbiological quality deteriorated.

·               L. monocytogenes was detected qualitatively in one sample, however, following quantitative analysis this sample was classified as satisfactory (i.e. <20cfu/g).  Although this finding is encouraging, it is imperative that businesses do not become complacent as this pathogen i) is ubiquitous in the environment, ii) is capable of growing at refrigeration temperatures, and iii) has a low infectious dose (levels of L. monocytogenes ³100cfu/g at the point of consumption are considered to represent a risk to consumers). 

Bacteriological Quality/Safety of Cooked Crustaceans and Molluscan Shellfish

This EU wide study was undertaken to investigate the bacteriological safety of cooked crustaceans and molluscan shellfish. These products are able to support the growth of a wide variety of microorganisms; in addition, certain features in their production make them susceptible to undesirable microbiological contamination and growth. Samples were obtained at both production and retail level. The Irish findings of this study were encouraging:

·              Production samples: All batch samples (n=3 batches) complied with the microbiological standards for Salmonella spp., S. aureus and E. coli as outlined in Community legislation (Commission Decision 93/51/EEC ⁽³⁾). There is no microbiological standard for V. parahaemolyticus in Community legislation; however, using the guideline proposed by the Commission for the purpose of this survey ⁽¹⁾ all production samples were classified as satisfactory (all samples in batch <30 cfu/g)

·              Retail samples: 99.8% (505/506), 97.42% (491/504), 99.2% (502/506) and 100% (492/492) of samples were classified as satisfactory for Salmonella spp, S. aureus, E. coli and V. parahaemolyticus respectively using the national microbiological guidelines for RTE foods ⁽²⁾.

Bacteriological Safety of Eggs produced under the Bord Bia Egg Quality Assurance Scheme (EQAS)

The Bord Bia Egg Quality Assurance Scheme (EQAS) is a salmonella control programme run in the Republic of Ireland. It is a voluntary integrated management scheme which incorporates recognised International Quality Management Systems, HACCP and EU legislation. The scheme incorporates additional Salmonella spp. controls to those specified in legislation. This study was undertaken to assess the impact of these controls on the bacteriological safety of EQAS eggs.

A total of 1,169 samples were tested (each sample comprised six eggs). Samples were obtained from EQAS approved farms, EQAS approved egg packing centres and retail premises. Salmonella spp. was not detected in any sample. Given the number of samples

taken and assuming that a negative sample equals the absence of salmonella in six eggs, the findings of this study show that there is a 95% certainty that the true infection rate lies below 1 in 2,657 eggs. This finding suggests that the control steps which are implemented are effective in controlling this pathogen.

Microbiological Quality and Safety of Pre-Prepared Rice

This study was undertaken to access the microbiological status of rice which was pre-prepared in catering premises. The microbiological quality (ACC and Enterobacteriaceae) and the microbiological safety (B. cereus) of the rice were determined using the national microbiological guidelines for ready-to-eat foods ⁽²⁾. The following were the main findings:

·              22.6% (115/508) and 14.6% (74/508) of samples were classified as unsatisfactory for ACC and Enterobacteriaceae respectively

·              0.6% (3/507) of samples were classified as unsatisfactory for B. cereus while 1.2% (6/507) were classified as unacceptable/potentially hazardous (i.e. ³10⁵cfu/g).  Information regarding storage conditions was provided with three of the six samples which were unacceptable/potentially hazardous for B. cereus. Two of these samples were stored at ambient temperature despite being cooked 12-24 hours previously. These conditions may have enhanced the proliferation of B. cereus cells.

The impact of food handling practices on the microbiological status of the samples was also determined. Information relating to food handling practices was obtained by means of a questionnaire which was completed at the time of sampling (questionnaires were returned with 300 samples, i.e. 59% response rate).

·              The time between cooking and sampling had a significant effect on microbiological status. 11.1% (10/90) of rice which was sampled within four hours of cooking was unsatisfactory compared with 32.7% (57/173) of rice which was sampled more than four hours after cooking

·              The storage conditions at the time of sampling (i.e. ambient or refrigerated) had no significant effect on the microbiological status of samples obtained within four hours of cooking. However, the storage conditions had a significant effect on samples obtained more than four hours after cooking. The samples with the poorest microbiological status were those sampled more than four hours after cooking and stored at ambient temperature

·              The quantity of rice cooked had no significant effect on microbiological status.

Additional information:

Reports on these surveys are published on the FSAI web site:

http://www.fsai.ie/surveillance/food/surveillance_food_micro2003.asp

The FSAI would like to thank all the staff of the official agencies who participated in the 2003 surveillance programme.

References:

1.      Commisssion Recommendation 2003/10/EC of 10 January 2003 concerning a co-ordinated programme for the official control of foodstuffs for 2003. OJ L 7/76 (11/01/2003)

2.            Food Safety Authority of Ireland. 2001. Guidelines for the Interpretation of Results of Microbiological Analysis of Some Ready-To-Eat Foods Sampled at Point of Sale. Guidance Note No. 3. http://www.fsai.ie/publications/index.asp

3.            Commission Decision 93/51/EEC of 15 December 1992 on the microbiological criteria applicable to the production of cooked crustacean and molluscan shellfish. OJ L 013, 21/01/1993, p. 0011-0013