Sources and survival of Listeria monocytogenes on fresh, leafy produce.

Listeria monocytogenes is an intracellular human pathogen which enters the body through contaminated food stuffs and is known to contaminate fresh leafy produce such as spinach, lettuce and rocket. Routinely, fresh leafy produce is grown and processed on a large scale before reaching the consumer through various products such as sandwiches and prepared salads. From farm to fork, the fresh leafy produce supply chain (FLPSC) is complex and contains a diverse range of environments where L. monocytogenes is sporadically detected during routine sampling of produce and processing areas. This review describes sources of the bacteria in the FLPSC and outlines the physiological and molecular mechanisms behind its survival in the different environments associated with growing and processing fresh produce. Finally, current methods of source tracking the bacteria in the context of the food supply chain are discussed with emphasis on how these methods can provide additional, valuable information on the risk that L. monocytogenes isolates pose to the consumer.

Staphylococcus aureus sensitivity to various antibiotics--a national survey in Ireland 1993.

The sensitivity of Staphylococcus aureus (S. aureus) to methicillin, penicillin, gentamicin, erythromycin, ciprofloxacin, fusidic acid and mupirocin was tested in 1152 clinical isolates from nine hospital microbiology departments. In all cases standard methods for culture and sensitivity were employed using either the Stokes' or a modified Stokes' method for susceptibility testing. The isolates were recovered from 1150 patients (606 men, 544 women; mean age: 41 years) and only those deemed relevant to the patient's clinical condition were included. Of the total 1152 isolates, 454 were regarded as hospital acquired, 506 were community acquired and the source of the remaining 192 isolates was unknown. The overall percentages of S. aureus sensitive to the tested antibiotics were as follows: methicillin 85%, penicillin 8%, gentamicin 89%, ciprofloxacin 85%, erythromycin 80%, fusidic acid 96%, mupirocin 98%. The sensitivity of the methicillin resistant strains to the other antibiotics tested was generally low except for fusidic acid and mupirocin, both of which retain good activity against methicillin resistant S. aureus (MRSA).

Efficacy of ofloxacin in the treatment of lower respiratory tract infections in general practice.

General practitioners assessed the efficacy and safety of ofloxacin in the treatment of lower respiratory tract infections in 100 patients. Treatment consisted of ofloxacin 200 mg twice daily for seven days. Evaluation of therapy was based on clinical and bacteriological parameters. Two patients were withdrawn from the study because of gastro-intestinal symptoms of nausea and vomiting. There were no significant drug-related alterations in haematological or biochemical parameters following treatment. Pathogens present in pre-treatment sputum specimens were eradicated from 63 of 66 patients. The overall assessment of response to treatment in the 98 evaluable patients was recorded as cured (45), much improved (47), slightly better (3), same (2) and slightly worse (1). It was concluded from these results that ofloxacin was both safe and effective in the treatment of lower respiratory tract infections.

The international spread of methicillin-resistant Staphylococcus aureus.

A genetic analysis of representative methicillin-resistant Staphylococcus aureus (MRSA) being isolated in London and Dublin hospitals has demonstrated that the epidemic strains from two London hospitals are different from the Dublin strains, but indistinguishable from the epidemic strains of eastern Australia. The possibility that some strains of MRSA are more likely than others to spread within hospitals is discussed.

The in-vitro activity of some antimicrobial agents against methicillin-resistant Staphylococcus aureus.

A total of 185 strains of methicillin resistant Staphylococcus aureus was investigated for sensitivity to five other antimicrobial agents. The vast majority of these strains were also resistant to gentamicin and fusidic acid. Rifampicin was the most active drug tested (MIC90, 0.007 mg/l), while two newer compounds teichomycin and ciprofloxacin showed equal and appreciable activity (MIC90, 0.5 mg/l).

Antibacterial prescribing patterns of doctors in the Irish Republic.

Antibacterial prescribing patterns of general practitioners and hospital doctors in a survey carried out this year (1982) were compared with those seen in previous surveys in 1977 and 1973. Since 1973, marked differences in preference for certain drugs in the treatment of urinary tract infection and diarrhoea were seen. Ampicillin, favourite antibiotic for treatment of respiratory infection in the previous surveys, remained first choice therapy in 1982 of both general practitioners and hospital doctors.

The effect of travel on faecal Escherichia coli serotypes.

In a study on the serotypes of Escherichia coli which are present in the faeces of students travelling from many parts of the world to Dublin, a great variety of types was found. It was not possible to relate certain types to the various parts of the world where the students came from. There was no decrease in variety of serotypes after the students had been in Dublin for a few months and no distinctive 'Dublin' types were acquired. Serological variation of the E. coli was suggested as partially explaining some of the variety of the serotypes found. Although eight students developed diarrhoea without an aetiological agent being isolated after arrival in Dublin, no distinct pattern of E. coli could be related to this.

The distribution of serotypes of Escherichia coli in cow-pats and other animal material compared with serotypes of E. coli isolated from human sources.

The serotypes of 13,139 strains of Escherichia coli isolated from humans were compared with the serotypes of 1076 strains isolated from animals. 689 of these strains were isolated from fresh cow-pats on 22 sites in England and Wales. 708 different O/H combinations were found. Of these, 520 were found in human strains only, 130 from animal strains only and 58 O/H serotypes from humans and animals. Approximately half of the animal strains could not be typed with the full set of sera used.

Bacterial colonisation and infection in spina bifida babies.

A Series of bacteriological investigations was carried out on 17 babies with spina bifida. Results showed that despite colonisation of their eyes, nose, throat, skin, umbilicus, wounds, urine and faeces with potentially pathogenic microorganisms, infections other than those of the urinary tract and brain were relatively uncommon.