Prevalence of Listeria monocytogenes in ready-to-eat foods sampled from the point of sale in Wales, United Kingdom.

A survey of Listeria in ready-to-eat food took place in Wales, United Kingdom, between February 2008 and January 2009. In total, 5,840 samples were taken and examined for the presence of Listeria species, including L. monocytogenes. Samples were tested using detection and enumeration methods, and the results were compared with current United Kingdom guidelines for the microbiological quality of ready-to-eat foods. The majority of samples were negative for Listeria by both direct plating and enriched culture. Seventeen samples (0.29%) had countable levels of Listeria species (other than L. monocytogenes), and another 11 samples (0.19%) had countable levels of L. monocytogenes. Nine samples (0.15%) were unsatisfactory or potentially hazardous when compared with United Kingdom guideline limits; six (0.10%) were in the unsatisfactory category (>100 CFU/g) for Listeria species (other than L. monocytogenes), and three (0.05%) were in the unacceptable or potentially hazardous category (>100 CFU/g) for L. monocytogenes. All three of these samples were from sandwiches (two chicken sandwiches and one ham-and-cheese sandwich). The most commonly isolated serotype of L. monocytogenes was 1/2a. This survey was used to determine the current prevalence of Listeria species and L. monocytogenes in ready-to-eat foods sampled from the point of sale in Wales.

Microbiological quality of ready-to-eat food served in schools in Wales, United Kingdom.

A survey of the general microbiological quality of ready-to-eat food served in schools was undertaken across Wales, United Kingdom. Of the 2,351 samples taken, four were identified as containing unsatisfactory counts of Escherichia coli, four contained unsatisfactory counts of Staphylococcus aureus, and one contained an unacceptable count of Bacillus cereus when compared with guidelines for the microbiological quality of ready-to-eat food published by the United Kingdom Public Health Laboratory Service in 2000. No samples contained detectable levels of Salmonella, Listeria species, or Clostridium perfringens. When compared with data on the general microbiological quality of food available in Wales, the food sampled from schools was of relatively better microbiological quality.

Incidence of genital Chlamydia trachomatis infection in the male partners attending an infertility clinic.

Chlamydia trachomatis is an important pathogen in the aetiology of pelvic inflammatory disease, resulting in female infertility. If all female infertility patients are screened for silent genital chlamydia infection, should the male partners of these patients also be screened to decrease the risk of re-infection? To determine the incidence of current and present male infection with C. trachomatis, we carried out a prospective clinical study. We studied 100 consecutive new male partners of patients seen in the infertility clinic. The infertility was of at least 12 months duration. We used polymerase chain reaction detection of C. trachomatis in urine specimens and microimmunofluorescence serology was performed to detect both past and current infection. The female partners were also screened for chlamydia infection by cervical swabs and serology. In five male patients (5%) C. trachomatis DNA was detected in the urine specimen by polymerase chain reaction. Microimmunofluorescence serology was positive in five patients (5%). One of the subjects had positive serology and urine polymerase chain reaction testing. The proportion of male partners with current or previous C. trachomatis infection was therefore 9% (95% CI 3.39 - 14.60). Seven female patients had positive serology results (7%), one of whom also had a positive cervical swab result indicating current infection with the pathogen. In four cases, both the male and female partner had positive serology results. The cost of screening for C. trachomatis is cheaper than treating the complications of undiagnosed genital Chlamydia infection, which is implicated in tubal disease leading to infertility. The results suggest that routine screening of male partners in an infertility setting may be justified.

Immunoglobulin therapy in non-menstrual streptococcal toxic shock syndrome.

We describe a case of non-menstrual streptococcal toxic shock syndrome requiring high doses of noradrenaline. The intravenous administration of pooled immunoglobulin was associated with improved haemodynamics and weaning of vasoconstrictors.

An outbreak of Salmonella enteritidis phage type 34a infection in primary school children: the use of visual aids and food preferences to overcome recall bias in a case control study.

Outbreaks of infectious intestinal disease are common in schools. Case control studies are useful in the investigation of infectious disease outbreaks but the time interval between illness and investigation can lead to recall bias, particularly in young children. We describe an outbreak of Salmonella enteritidis phage type 34a infection involving 54 clinical cases in two adjacent schools, and a novel approach to overcome recall bias. The likely dates of infection were identified from the epidemic curve. We created a visual display of the menu from those days and asked 9 cases and 18 matched controls to identify their food preferences from this display. Preference for chocolate mouse was significantly associated with illness (P = 0.006). The results of the case control study agreed with the findings of the environmental investigation. We believe our approach could be used in other circumstances, where subjects are young children or recall bias is a concern.

The value of Chlamydia trachomatis antibody testing as part of routine infertility investigations.

Laparoscopy is considered the gold standard for the evaluation of tubal disease but it is an invasive and costly procedure. Chlamydia trachomatis antibody testing is simple and inexpensive and causes minimal inconvenience to the patient. Using the micro-immunofluorescence technique we assessed the significance of positive serology. There was a marked association between the titre and the likelihood of tubal damage. In the group with low titres (1 in 32) there was only a 5% incidence of tubal damage; however, there was a progressive increase in the incidence of tubal damage in those with higher titres. Twenty out of 57 patients with titres higher than 1 in 32 had tubal damage (35%). The difference between the two groups was statistically significant (P < 0.0001, chi(2) test). By using C. trachomatis antibody testing more widely it may be possible to reduce the number of laparoscopies performed. It should therefore become an integral part of the fertility work-up.

Antimicrobial activity of glycerine-ichthammol in otitis externa.

The clinical efficacy of glycerine-ichthammol in otitis externa may be due to an anti-inflammatory action of ichthammol or a dehydrating effect of glycerine on the oedematous ear canal. Its antimicrobial activity, if any, against the common organisms in otitis externa is not well known. A study of the antibacterial property of glycerine-ichthammol as measured by a growth inhibition test and a modified cidal assay, showed inhibition of selected gram positive organisms (Streptococcus pyogenes and Staphylococcus aureus) by ichthammol and glycerine-ichthammol combination, but only negligible antibacterial activity against Pseudomonas aeruginosa and Escherichia coli. Candida albicans was also weakly inhibited. As the activity against gram negative organisms is minimal, incorporation of an anti-gram negative antibiotic such as gentamicin in the glycerine-ichthammol compound to enhance its antibacterial spectrum is suggested.

Serological diagnosis with the Chlamydia Spot-IF test.

Using a set of sera for which full chlamydial micro-immunofluorescence results suggested a clear diagnosis, we have evaluated the Chlamydia Spot-IF test (bioMerieux), which allows a comparison of titres to Chlamydia trachomatis and C. psittaci antigens. A modification of the test in which the antigen slides were pre-treated with a monoclonal antibody to chlamydial lipopolysaccharide, improved its ability to differentiate infections with C. trachomatis from those with C. psittaci or C. pneumoniae.

The acquisition of antibiotic resistant coagulase-negative staphylococci by aortic graft recipients.

The staphylococcal flora of the groin and perianal area was studied in 12 patients undergoing aortic grafts and 3 patients having repair of ventral abdominal hernias. A total of 892 isolates of coagulase-negative staphylococci (CNS) were identified and their antibiotic resistance determined. The species most frequently isolated were S. epidermidis and S. haemolyticus with the latter showing the highest incidence of antibiotic resistance. Five of 15 patients had CNS resistant to methicillin and gentamicin on admission. The effect of pre-operative bathing with chlorhexidine was studied in 6 patients and appeared to reduce the acquisition of multi-resistant CNS in the week after operation.

Sputum microbiology in a district general hospital. The role of Branhamella catarrhalis.

Evidence is presented that supports the view that Branhamella catarrhalis has a pathogenic role in chronic chest disease, similar in many respects to Haemophilus influenzae. It was isolated from 4% of sputum specimens (compared to 10% for Haemophilus influenzae). Fifty-three per cent produced beta-lactamase, and all were resistant to trimethoprim. The relevance of these findings to antibiotic treatment is discussed.