Surveillance of primary antibiotic resistance of Helicobacter pylori at centres in England and Wales over a six-year period (2000-2005)

Antibiotic resistance is a key factor in the failure of Helicobacter pylori eradication therapy, yet few sentinel schemes exist to monitor trends in resistance at local, national or international levels. This study aimed, over a six-year period, to monitor resistance levels of H. pylori in England and Wales to the four antibiotics used in its treatment. A total of 1,310 isolates from Gwynedd in north Wales and from mid-Essex in south-east England were collected from 2000 to 2005 and tested for susceptibilities to metronidazole, clarithromycin, amoxicillin and tetracycline. Overall, metronidazole and clarithromycin resistance rates were 28.6% and 8.3% in Gwynedd and significantly higher (36.3%, p=0.0031, and 12.7%, p=0.0112) in mid-Essex. Rates of resistance to metronidazole and clarithromycin increased in both areas over this six-year period. Resistance rates were higher in female compared with male patients (38.1% vs 26.6% for metronidazole, p<0.0001, and 12.9% vs 7.5% for clarithromycin, p=0.0024), and were higher in patients <45 years compared with those ?45 years (44.0% vs 29.0% for metronidazole, p=0.0002, and 15.0% vs 9.4% for clarithromycin, p=0.0233). This study highlights the importance of antibiotic resistance surveillance in H. pylori for providing information on local resistance rates for test and treat strategies.

Pressure sore prevention pads as an infective source in orthopaedic theatres

Current theatre practice and protocol involves the use of pressure sore prevention pads in the positioning and support of all patients undergoing orthopaedic surgery. Microbiological swabs were taken from those pads placed adjacent to the operative field immediately before implant surgery. Eleven out of the 13 pads sampled yielded bacterial growth capable of causing deep-seated infection. The transfer of these pads between the designated orthopaedic theatres and the rest of the theatre complex was also noted. We recommend that the use of these pads should be closely reviewed. They should either be used with stricter guidelines for decontamination between use or disposable 'clean' alternatives sought.

Cytomegalovirus infection in immunocompetent patients

Symptoms associated with cytomegalovirus (CMV) infection in immunocompetent patients are not well documented. From December 1998 through June 2001, serum samples obtained from 7630 patients in Cambridge and Chelmsford, United Kingdom, were tested for CMV immunoglobulin M. CMV immunoglobulin G avidity was used to confirm CMV infection. A total of 124 patients (106 patients treated by general practitioners [GPs] and 18 hospitalized patients) with CMV infection were identified. The most frequent symptoms were malaise (67%), fever (46%), and sweats (46%), and the most frequent finding was abnormal liver function test results (69%). Twelve percent of patients had a relapsing illness, and many had symptoms that lasted for up to 32 weeks (mean duration of symptoms, 7.8 weeks). GPs reported that there was a significant benefit in making the diagnosis of CMV infection; it provided reassurance and avoided the need for further investigations. We have identified symptoms associated with CMV infection in immunocompetent patients who present to GPs or who are admitted to the hospital.

Determination of Helicobacter pylori vacA allelic types by single-step multiplex PCR

AIMS

To develop and evaluate a novel multiplex PCR assay that enables definition of Helicobacter pylori vacA allelic type in a single reaction.

METHODS AND RESULTS

Application of the one-step system to DNA extracts from 22 cultures of known vacA genotype demonstrated that it was highly accurate. Analysis of 15 matched gastric biopsy/culture pairs generated exactly correlating genotype profiles. vacA genotypes were determined from an additional 62/70 gastric biopsies from dyspeptic patients of known H. pylori positive status by the one-step assay, compared with 63/70 by the original two-reaction test. Types s1/m1, s1/m2 and s2/m2 were identified in 51.9%, 31.2% and 16.9% of biopsies, respectively.

CONCLUSIONS

The multiplex PCR system developed enables rapid one-step vacA genotyping that is accurate, easy to interpret and more economical than the alternative multiple-reaction tests. Application of this system to gastric biopsies from patients in South-east England demonstrated that s1/m1 was the most common genotype, while s1/m2 and s2/m2 were less prevalent.

SIGNIFICANCE AND IMPACT OF THE STUDY

This simple one-step system can be applied direct to antral gastric biopsies without the need for culture, thereby facilitating rapid surveillance of vacA genotype in relation to geographical location and disease status.

Surveillance and clinical relevance of vacA genotypes of Helicobacter pylori infecting dyspeptic patients in mid-Essex

The Helicobacter pylori vacuolating cytotoxin is a putative pathogenicity factor encoded by vacA, a mosaic gene with a global distribution. The vacA type prevalence and diversity of H. pylori isolated from antral gastric biopsies of 360 dyspeptic patients in mid-Essex, and of 79 patients from other locations, were investigated in order to test for links with disease severity. Mid (m)-region genotyping and subtyping by vacA HaeIII RFLP (restriction fragment length polymorphism) analysis showed that the m1 and m2 alleles were diverse, with 191 different subtypes. Variation in 44% of strains was accounted for by ten subtypes of which subtype v-1 represented a conserved core (33%) of the m1 form. Prevalence rates for combined mid and signal (s)-region genotypes were 40% for s1/m1, 46% for s1/m2, and 11% for s2/m2. Overall, vacA genotyping provided high typability and discrimination, but no specific RFLP markers could reliably predict a clinically significant presentation due to an H. pylori infection.

Build your own infection control link nurse: an innovative study day

Infection control is everyone's business and it is important that all members of staff observe good infection control practice. An effective infection control link nurse system has been shown to support and develop this approach. The strength of ward-based infection control link nurses depends upon their effectiveness as role models and their ability to influence practice on their wards and beyond. In addition, the degree of respect they command from their peers and colleagues and the amount and quality of knowledge they possess is crucial. This paper describes an innovative approach taken in Mid-Essex, which allowed infection control link nurses to assess their capabilities and limitations in communicating with and influencing colleagues. In addition, we show how quantitative measures may be made available by this approach. Such measures may be used to explain to management how particular areas of infection control practice (e.g. the need for infection control link nurses to have more authority and more 'muscle') may be important.

PCR-based diagnosis of Helicobacter pylori infection and real-time determination of clarithromycin resistance directly from human gastric biopsy samples

A novel PCR detection assay that amplifies the Helicobacter pylori-specific vacuolating cytotoxin gene (vacA) and thus enables rapid diagnosis of infection is described. Additionally, a real-time probe hybridization melting point analysis assay to detect all three mutations in the 23S rRNA gene associated with clarithromycin resistance was applied directly to antral gastric biopsy samples. Comparison with culture and an alternative PCR assay targeting the 16S rrn gene showed that the vacA assay was sensitive and specific when tested on biopsy samples from 121 patients. Clarithromycin susceptibilities could be determined in the majority (92.3%) of culture-positive gastric biopsy samples analyzed, four of which generated melting peaks indicative of clarithromycin resistance by either an A-->G or A-->C mutation. The presence of the mutations correlated with the clarithromycin disk diffusion sensitivities of matched cultures. This PCR-based system was simple to perform and could be completed in 3 to 4 h, thereby overcoming the delays associated with conventional culture methods for H. pylori identification and susceptibility testing.

Genetic diversity in the Helicobacter pylori cag pathogenicity island and effect on expression of anti-CagA serum antibody in UK patients with dyspepsia

AIMS

To investigate variation within the cag pathogenicity island (PAI) of Helicobacter pylori isolated from patients with dyspepsia in mid-Essex, and to evaluate the effect on expression of anti-CagA antibody.

METHODS

Sixty two isolates of H pylori cultured from gastric biopsies were screened by specific PCR assays for the presence of cagA and other gene markers (cagD and cagE, and virD4) in the cag PAI. An enzyme linked immunosorbent assay (ELISA) kit (Viva Diagnostica helicobacter p120) was used to test for anti-CagA IgG antibody in matching sera. Isolates were also genotyped by vacuolating cytotoxin polymerase chain reaction (PCR) analysis, and tested for absence of the complete cag PAI (empty site PCR assay).

RESULTS

Forty one of the H pylori isolates had a cag PAI containing cagA. One strain had no cagA but other cag PAI loci were present, whereas the remaining 20 strains had no detectable cag PAI markers. Anti-CagA IgG antibody was detected in 34 sera by the ELISA assay, and when compared with the cag PAI genotype of the infecting strain, accuracy, sensitivity, and specificity were 92%, 87%, and 100%, respectively. The seven discrepant or borderline strains in the ELISA were all vacA s1 but differed in other genotypic markers.

CONCLUSIONS

The cag PAI was widely distributed in H pylori from patients with dyspepsia in mid-Essex who had different gastric pathologies. Infection with a strain having an uninterrupted cag PAI was associated with the presence of anti-CagA antibody in most patients. Discrepant ELISA results, mostly for elderly patients with duodenal ulcers, were attributed to cagA associated variation, particularly to the presence of mixed cagA+/cagA- cell variants in the infecting strain population. Tests for anti-CagA serum antibody were unreliable for predicting severity of clinical disease associated with H pylori infection in this series of patients.

Molecular epidemiology of Helicobacter pylori in England: prevalence of cag pathogenicity island markers and IS605 presence in relation to patient age and severity of gastric disease

The cagA gene is a key marker for the Helicobacter pylori cag pathogenicity island (PAI), which may vary in composition in different strains with insertion sequence mediated interruptions and deletions of genes. While presence of cagA has been associated with increased risk for peptic ulcer disease and gastric cancer, the precise link with virulence is controversial. We investigated H. pylori from dyspeptics in one location in England (mid-Essex) with reference to the prevalence and distribution by age cohort of different cag PAI forms to determine if presence of the insertion element IS605 had a modifying effect on the severity of associated disease. H. pylori isolated from gastric biopsies over a 4-year period were screened by specific PCR assays for the presence of cagA, cagD, cagE and virD4 genes in the cag PAI, and for the presence of IS605 in the PAI and elsewhere in the genome. Most (68%) of the 166 isolates of H. pylori contained a PAI based on detection of cagA whereas 29% had no detectable PAI using multiple loci. The cagA+ genotype frequencies were similar in the peptic ulcer and non-ulcer dyspepsia-gastritis groups (79% vs. 74%) whereas frequencies in the NUD-oesophagitis and normal mucosa groups were lower (58%) but not significantly different (P>0.41). Genomic IS605 inserts were present at an overall frequency of 32% and were widely distributed with respect to patient age and disease severity. The combined cagA+/IS- strain genotype was common but not significantly associated with PUD compared to endoscopically normal mucosa (P> or =0.807). We concluded that presence of the IS605 element, whether in cagA+ or cagA- strains of H. pylori, did not systematically modify the severity of associated disease in the study population.

Clinical governance and infection control in the United Kingdom

The recent organizational changes in the NHS have at their core the concept of clinical governance. Although initially poorly defined and understood this term has now taken on a clear identity, placing quality alongside fiscal probity and corporate governance at the top of NHS priorities. Integral to clinical governance are the basic elements of clear national standards for services and treatments that are to be locally delivered through assured, monitored, high quality healthcare. It is within this framework that workers in infection control must develop their own methods of applying clinical governance. This review explores the implications that the strategy of clinical governance holds for the speciality of infection control, emphasizing the benefits its active adoption can bring and highlighting the key relevance of clinical risk management in this setting. It illustrates clinical governance as a tool to engage colleagues on a multi-disciplinary front, most particularly the crucial link to senior Trust management.

Pasteurella multocida meningitis in infancy - (a lick may be as bad as a bite)

Pasteurella multocida is the commonest cause of local infection after an animal bite, but is an unusual cause of meningitis. We report a case of P. multocida meningitis occurring in a 7-week-old infant which was contracted after non-traumatic contact with a household pet, that is, without any animal bite or scratch. The organism may be easily confused with more common Gram-negative pathogens. In this case, it was initially incorrectly diagnosed as Haemophilus influenzae type b (Hib); a possibility which has important implications in the era of routine use of Hib vaccine in infant immunisation programs.

CONCLUSION

Pasteurella multocida is an unusual, but serious cause of meningitis in infancy. It is potentially preventable by the avoidance of contact between young infants and the saliva of household pets, in particular by assiduous hand hygiene.

Development of a scheme for genotyping Helicobacter pylori based on allelic variation in urease subunit genes

Helicobacter pylori urease subunit genes in 383 isolates from 10 countries were investigated by PCR-restriction fragment length polymorphism (HaeIII) analysis. Eighty-two different ureAB profiles were documented by reference to known sequences. Variation among 51% of strains was accounted for by 10 predominant patterns, which provided a unique framework for categorizing isolates with geographically diverse origins.

Human enteric pathogens identified in a London teaching hospital and a rural public health laboratory: 1994

Two microbiology laboratories, one serving an inner city hospital and one a rural public health laboratory, collected data on the outcome of examining faecal specimens in 1994. Overall, 6.7% of the investigations were positive, but the rates were lower for hospital inpatients, for recently described pathogens, and in the absence of relevant clinical details; rates were higher for patients with a history of foreign travel. No benefit was gained by examining more than two specimens from any patient. Clostridium difficile was the only investigation frequently positive among patients already in hospital, and virological tests were often positive in patients investigated by general practitioners.

The development of an infection control link-nurse programme in a district general hospital

Management of hospital-acquired infection is costly, and a vital part of risk management. It is also closely linked with the quality of patient care. Information regarding hospital-acquired infection is increasingly being sought by both purchasers and providers. This paper describes the setting up and development of an infection control link-nurse system over a four-year period in a district general hospital. It gives practical details of methodology and problems encountered. Emphasis is given to the incorporation of infection control principles into ward and departmental standard setting. Having set up the system, subsequent monitoring of the process by a clinical audit programme is described. The importance of the responsibility of staff, at ward and departmental level, in high-level infection control practice is discussed.

Methicillin resistant Staphylococcus aureus in three adjacent health districts of south-east England 1986-91

The experiences with methicillin-resistant Staphylococcus aureus (MRSA) of two contiguous Health Districts during 1986-91 and of a third mutually adjacent District in south-east England during 1989-91 were compared. Although the three Districts were in many ways similar, the nature of the problems posed by MRSA differed. The Districts had dealt with MRSA independently but had evolved similar strategies for coping with the organism. In two Districts a gradual relaxation of case-finding and of infection control precautions applied to individual patients and outbreaks, was followed by a reduction in the number of new patient-isolates identified from routine bacteriology specimens. Standardization of MRSA isolation rates for patient throughput and for length of hospital stay showed the examination of crude total isolates to provide misleading comparisons of relative risks of acquiring MRSA in different specialties. It was also found that patients discharged from specialties with short inpatient stays were more likely to have MRSA detected after discharge by their physicians working in the local community served by the hospitals but there was no evidence of spread outside hospital. It is suggested that good all-round standards of infection control practice are more important than specific radical policies in dealing with endemic MRSA.

An outbreak of Salmonella saint-paul infection associated with beansprouts

In March 1988, there was an outbreak of infection by a strain of Salmonella saint-paul with a distinctive antigenic marker. A total of 143 reports were received between 1 March and 7 June. Preliminary investigations suggested that raw beansprouts were a possible source of infection and a case-control study confirmed the association. S. saint-paul of the epidemic type was isolated from samples of beansprouts on retail sale in different cities in the United Kingdom and from mung bean seeds on the premises of the producer who was most strongly associated with cases. In addition, Salmonella virchow PT34 was isolated from samples of raw beansprouts and was subsequently associated with seven cases of infection. Four other serotypes of salmonella were also isolated from beansprouts. On 8 April the public were advised to boil beansprouts for 15 seconds before consumption, and the premises of the one producer associated with many cases were closed. As a result of these actions there was a significant decrease in the number of infections with S. saint-paul.

Failure of influenza vaccine to prevent two successive outbreaks of influenza A H1N1 in a school community

Forty nine of the 149 boys (33%) at a preparatory school fell ill at the beginning of the autumn term 1986 with symptoms of influenza. One hundred and eighty two of the 470 pupils (39%) in the senior part of the same school had similar symptoms of influenza at the beginning of the spring term 1987. A new variant of influenza A H1N1 virus was isolated from both outbreaks and shown to be antigenically similar to A/Taiwan/1/86. The attack rate among pupils who had previously received trivalent influenza vaccine containing A/Chile/1/83 H1N1 antigen was not significantly different from the rate among those who had never been vaccinated. It is concluded that annual vaccination of all boarding school pupils may be inappropriate.

The presence of M proteins in outbreak strains of Streptococcus equisimilis T-type 204

Cultures of Streptococcus equisimilis (Lancefield group C) from three outbreaks of illness were found to carry the T-protein antigen 204. Strains of this type were not otherwise represented in a collection of 743 cultures of these 'pyogenes-like' streptococci isolated from other outbreaks of infection or as random isolates. Two of the three outbreaks were of pharyngitis. The third arose in a maternity unit where the organism was isolated from mothers with puerperal fever, from staff and also from the environment. Representative strains were found to carry M-protein antigens as judged by their ability to survive and multiply in fresh normal human blood. Comparison of absorbed rabbit antiserum to the M antigens in opsonic and precipitin tests showed that a distinct M antigen was present on isolates from one outbreak of sore throat and that all cultures from the other two incidents shared a common M antigen. Samples of serum were also available from patients in the outbreak of puerperal sepsis. Most patients developed antibodies to one or more streptococcal antigens including the M protein, streptolysin O, streptokinase and the hyaluronidase specific for strains of group C and group G streptococci.

An outbreak of puerperal fever caused by group C streptococci

Between 19 February and 18 April 1987, 33 confirmed cases of puerperal fever caused by Streptococcus equisimilis serotype T204 occurred at three hospitals in and around Chelmsford. Most of the cases (70%) occurred on one ward, in which toilet seats and a shower are believed to have aided transmission, although insufficient data were obtained to exclude a role for person-to-person spread. Possession of M-protein antigen was demonstrated in the outbreak strain.

Chlamydia trachomatis as a cause of neonatal conjunctivitis

Chlamydia trachomatis was identified in 37 of 73 consecutive neonates with purulent conjunctivitis, including four delivered by caesarean section with intact membranes. Most (28/37) presented in the first week. Infection was significantly associated with referral from the community. Genital C. trachomatis infection was present in 13 of 35 parents of affected infants.

Diagnosis of Nocardia pneumonia by transtracheal aspiration

We report a case of pulmonary nocardiosis in which the microbiological diagnosis was made by transtracheal aspiration after all conventional methods had failed. The simplicity of the technique and the importance of diagnosing nocardiosis are discussed.