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Bacterial biofilm in dental unit waterlines (DUWs) is a widespread problem, and poses a potentially significant risk of infection to dental staff and patients, particularly those who are medically compromised or immunocompromised. The purpose of the present study was to investigate the level of bacterial contamination of dental chair unit output water in the Dublin Dental Hospital, and to investigate the efficacy of two hydrogen peroxide-based disinfectants in reducing bacterial loads to ≤200cfu/mL as recommended by the American Dental Association. The chemical quality of dental chair unit input and output water was well within the limits recommended for potable water. Water supplied to the units yielded an average aerobic heterotrophic bacterial cell density of 184cfu/mL. However, the corresponding density in output water was considerably higher; the average cell density in water from the three-in-one air/water syringes and cup fillers in 12 chairs was 8200 and 4300cfu/mL, respectively. Dental unit water obtained from 18 separate reservoir-supplied units in general practices in the Dublin area yielded an average of 66000cfu/mL. The bacterial species found were predominantly environmental organisms, which were also present at low levels in the input water. Some of the species identified (e.g., Burkholderia cepacia and Pseudomonas fluorescens ) are known opportunistic pathogens. The capacity of two disinfectants, Sterilex Ultra and Sanosil, to reduce bacterial contamination to safe levels was compared. In a controlled study, once weekly overnight (15h) disinfection using either agent reduced the bacterial density to below the American Dental Association recommended level of 200cfu/mL. However, once disinfection ceased the bacterial loads increased to unacceptably high levels within three weeks. Electron microscopic analysis showed that both disinfectants markedly reduced biofilm in the DUWs, but the biofilm rapidly became extensive again when once weekly disinfection ceased. While both disinfectants were equally effective in lowering the bacterial counts to acceptable levels, Sterilex Ultra was associated with clogging of DUWs in some dental chair units after repeated usage, suggesting that Sanosil is a more suitable agent for routine use.

Objective: toxigenic Clostridium difficile is responsible for a spectrum of disease severity ranging from mild diarrhoea to fulminant colitis. This study attempts to determine the proportion of patients in each category of severity and evaluate the risk factors for a more prolonged and complicated course. Design: prospective cohort study. Setting: university teaching hospital. Subjects: all patients with symptomatic C. difficile infection during 4 months of an outbreak (January‐April 1995); n = 73; median age 74 years (range 17‐91). Measurements: incidence of C. difficile-associated disease (CDAD); severity of disease; percentage of patients in each category of severity; risk factors for severe disease/prolonged symptoms (univariate and multivariable analyses). Results: the incidence of CDAD was 0.93%. Of the cases identified, 18 (24.7%) had mild, self-limiting disease; 26 (35.6%) had moderately severe disease; 23 (31.5%) had prolonged symptoms and six (8.2%) had a complicated course. Although CDAD was more common in older patients (P < 0.001), increasing age was not a risk factor for severity. Significant risk factors for severe CDAD included low Barthel and abbreviated mental test scores (P < 0.01, P < 0.001 respectively) and recent endoscopy (P = 0.03). Logistic regression analysis revealed the following independent predictors of severe CDAD: endoscopy [odds ratios (OR) 4.0, P = 0.03] and cognitive impairment (OR 11.0, P < 0.01). A trend towards significance was noted for nasogastric tube insertion (OR 3.1, P = 0.08). Complications of infection included dehydration, malnutrition and faecal incontinence (which was statistically significantly associated with more severe disease; P < 0.01). Conclusion: risk factors for severity of CDAD include functional disability, cognitive impairment, and recent endoscopy. Anticipation of severe CDAD may limit morbidity and mortality.

We report an outbreak of Clostridium difficile -associated disease (CDAD) in a large Dublin hospital. From January to June 1995, inclusive, 139 patients were affected; the mean age of cases was 68·8 ± 19 years. Clinical information is available for 73 cases identified during the first four months of the outbreak. The majority of patients presented with abrupt onset of watery diarrhoea; however, 19·2% presented with an unexplained pyrexia following a course of antimicrobial therapy and 5·5% presented with a surgical acute abdomen. Twenty patients (27·4%) experienced relapsing disease and seven (9·6%) patients died. Seventy-six percent of cases received a cephalosporin prior to the onset of disease, the highest relative risks occurring with third-generation agents; however, 9·6% of patients affected had not been exposed to antimicrobial therapy in the preceding eight weeks. Pyrolysis mass spectrometry identified two clusters of isolates, representing two strains of C. difficile . There was marked spatial clustering of these strains, with each confined to a separate area of the hospital. Infection control measures and an antibiotic policy were introduced. Throughout the outbreak period the use of the most frequently used cephalosporin in the hospital increased; this was accompanied paradoxically by a reduction in the number of new cases of CDAD.

During a six-week period a cluster of four cases of Candida fungaemia occurred in a mixed haematology/oncology unit of a large Dublin teaching hospital. A study was conducted to determine whether the cluster of cases was caused by a particular strain. Nine patients were studied; five who were colonized with Candida spp. and four who developed Candida fungaemia. Twenty-two clinical isolates of Candida spp. were collected and identified. Three of the patients with fungaemia yielded Candida albicans from blood cultures and C. tropicalis was isolated from the fourth patient. C. albicans isolates were serotyped, morphotyped and analysed by DNA fingerprinting of total cellular DNA using the cloned C. albicans-specific, mid-repeat sequence element 27A as a molecular probe. All C. albicans isolates were of serotype A. Eight distinguishable types were identified by both morphotyping and DNA typing from 19 C. albicans isolates recovered from seven individual patients, although there were several discrepancies. Of three patients from whom two or more isolates of C. albicans were recovered on separate occasions, two yielded recurrent isolates with different morphotype codes. However, in both cases, the recurrent isolates from individual patients yielded indistinguishable, or closely related, DNA fingerprint profiles. Both morphotyping and DNA fingerprint analysis readily distinguished the three blood culture isolates of C. albicans. We conclude that the Candida spp. infections in the unit were not due to cross-infection and were probably related to the patients' indigenous flora.

Lipid malabsorption is a common clinical manifestation of small bowel bacterial overgrowth. Its pathogenesis, however, remains controversial. Bacteroides melaninogenicus ssp. intermedius, an anaerobic bacterium, is commonly isolated from the upper bowel of patients with small intestinal bacterial overgrowth. The effects of a culture supernate of this organism and deoxycholate, an unconjugated bile salt, on intestinal oleic acid absorption were examined using a rat closed-loop model. The supernatant reduced the in vitro uptake of oleic acid by 19% (P0.001). Deoxycholate did not significantly reduce the lipid absorption. Combined supernate and deoxycholate did not have an additive effect on absorption of oleic acid. We conclude that anaerobic bacterial products may contribute to the malabsorption of lipid in the setting of bacterial overgrowth of the small bowel.

The minimum inhibitory concentrations (MICs) of cefaclor, co-amoxiclav, clarithromycin and ciprofloxacin for 59 strains of vaginal lactobacilli were determined by both the reference agar dilution and E test methods. With the exception of clarithromycin, there was poor correlation between the results obtained by the two techniques. This was most apparent for the β-lactams studied, the MICs of cefaclor as determined by the E test being particularly difficult to define. The stability of antimicrobial gradients in the E test may cause problems when testing slow-growing bacteria and/or organisms which grow only under anaerobic conditions. Accordingly, only those MICs determined by the agar dilution method are reported. The percentages of susceptible isolates were as follows : clarithromycin, 100 ; co-amoxiclav, 100 ; cefaclor, 20 ; and ciprofloxacin, 4. The administration of antimicrobials, such as ciprofloxacin and cefaclor, which have poor activities in vitro against lactobacilli, may therefore be advantageous to the host because it allows the protective effects of the normal vaginal flora to be preserved.

Summary. Between Dec. 1992 and Aug. 1993, the MRSA population in the Federated Dublin Voluntary Hospitals and St James's Hospital group was studied with an antibiogram-resistogram (AR) typing scheme in which AR patterns were determined by testing susceptibility to 22 antibiotics and chemicals by a modified Stokes' disk diffusion technique. The typing scheme divided this MRSA population into 31 AR types but 90% of isolates belonged to seven types. Isolates belonging to the most frequently occurring types (AR types 13 and 14) differed only in their reaction to lincomycin (or clindamycin) and could not be distinguished by phage typing, plasmid profiling or restriction endonuclease analysis. The AR typing scheme showed that the incidence of different AR types varied in different hospitals and changed during the study period. This typing method differentiated a strain of MRSA responsible for a nosocomial outbreak in an intensive care unit from other MRSA isolated in the unit, and has distinguished imported strains from local ones. In one hospital, AR typing showed that, although a major outbreak occurred with one AR type, there was also a series of smaller outbreaks with other AR types. The technique can be performed in the diagnostic laboratory and results were available within 24 h.

Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA) is an important nosocomial pathogen. A problem encountered in the control of staphylococcal nosocomial infection is the difficulty correlating data available from antimicrobial susceptibility patterns (usually available locally) with phage typing patterns which are generally determined in a reference laboratory. Data problems are exaggerated because many patients have numerous samples taken over long periods of time. This paper describes the use of a database, 'DataEase', on a personal computer to correlate available data with patient demographics and to present the resulting information in whatever format is required. The information might be presented as the phage pattern of each isolate from patients in a particular unit per month or as a combination of the phage types and antimicrobial susceptibility patterns of isolates from a particular unit. The system can be used to generate a list of all isolates for phage typing in a format that allows the phage typing pattern to be recorded directly onto the list worksheet. In addition to providing clinically relevant reports, the system simplifies the collation of epidemiological information, data from which showed that since 1987 the incidence of MRSA has been rising in the group of hospitals served by this laboratory; MRSA of phage type 83A became a problem during 1990 and 1991; the incidence of gentamicin-sensitive phage type non-typable MRSA increased fourfold between 1988 and 1991; and the incidence of gentamicin-resistant MRSA rose sharply in 1992.

Objectives: To assess the prevalence of typical clinical features and need for treatment of small intestinal bacterial overgrowth (SIBO) in the elderly. Design: Random selection of patients, regardless of their nutritional status. Setting: Acute admissions ward in the Dept. of Medicine for the Elderly. Patients: Thirty elderly patients between 68 and 90 years of age. Measurements: Active clinical problems, including the presence of recent weight loss and diarrhea, were recorded. Routine blood tests, including serum vitamin B12, red cell folate, albumin and calcium, and qualitative small bowel bacteriology results, were analyzed. The effect of age on all variables was studied. Results: Twenty of the 30 small bowel aspirates had proven SIBO, and strict anaerobes were isolated in 15. The mean blood test values did not differ significantly between culture-positive and culture-negative patients. There was no significant correlation between those variables and the total bacterial counts. Of the 20 proven SIBO cases, eight had anemia, five had hypoalbuminemia, five had diarrhea, four complained of recent weight loss, and none had B12 deficiency. Alternative causes other than SIBO were identified for many of these abnormalities. Advancing age correlated significantly with rising counts of small bowel strict anaerobes. Conclusions: These data suggest that age may be a predisposing factor in the development of anaerobic overgrowth but that SIBO is a benign entity in the elderly. Contrary to previous recommendations, treatment of this condition is not routinely indicated.

Susceptibility to metronidazole of 213 clinical strains of H. pylori from dyspeptic patients was determined by a plate dilution method. Seventy two (33.8%) of the strains were resistant to metronidazole (MIC > 8 mg/L), 20 of these were from 24 patients who had received previously metronidazole (83.3%), giving a primary (pretreatment) resistance rate of 27.5% (52/189). The resistance rate was higher in women than in men, especially aged 50 to 59 years old (43.6% vs 23.3%, p < 0.001). The resistance rate was lower in patients at 60 or over (9.8%), but similar between the younger patients groups (38.8% - 49.0%). There was no difference in the resistance rate between peptic ulcer disease (32.6%) and nonulcer dyspepsia (34.7%). These data indicated that metronidazole resistance in H. pylori is absolutely associated with previous use of the drug, and the higher resistance rate in women may be due to the more frequent prescription of the drug for their gynaecological infection or operation. Therefore, testing of susceptibility of H. pylori to metronidazole is important. A new susceptibility testing technique, the E-test was evaluated in this study and found to give comparable results to the plate dilution method and also had the advantage of being simple to perform.

Fifty two strains of anaerobic bacteria isolated from the upper gut of patients with small intestinal bacterial overgrowth were screened for phospholipase activity. Bacteroides melaninogenicus spp intermedius had the greatest activity. The effects of culture supernatants of this organism and deoxycholate on intestinal calcium absorption and disaccharidase activity were studied using a rat closed loop model. The supernatant decreased the in vitro uptake of calcium by 15% (p less than 0.001). Deoxycholate reduced calcium uptake by 16% (p less than 0.001). Combined culture supernatant and deoxycholate reduced calcium uptake by 39% (p less than 0.001) suggesting a potentiation of supernatant activity by deoxycholate. Culture supernatant and deoxycholate, both alone and combined, significantly reduced lactase, sucrase, and maltase activity. Electron microscopic evidence showed degeneration of microvilli, disruption of mitochondrial structure, and swelling of the endoplasmic reticulum after exposure of the intestinal loops to the supernatant or deoxycholate.

Background With increasing antibiotic usage Clostridium difficile colitis is becoming more common. Surgery for fulminating C. difficile colitis, however, is rare because of the effectiveness of specific anticlostridial chemotherapy. Surgical outcome in five patients with fulminating C. difficile colitis involved in a recent outbreak of this disease is reported. Methods Five of 138 patients developed fulminating C. difficile colitis unresponsive to medical therapy. All patients had antibiotics in the preceding period. Indications for operation in those who underwent surgery were systemic toxicity with a pyrexia, marked leukocytosis and abdominal signs leading to progressive organ failure, despite appropriate anticlostridial antibiotic therapy. Results At operation all patients had a markedly oedematous colon with normal serosa but with acute mucosal colitis. All underwent subtotal abdominal colectomy and ileostomy. Progressive organ failure persisted in four, leading to death, giving a mortality rate of four in five in the operated group in comparison with 3·8 per cent (five of 133 patients) in those treated medically. Conclusions These results indicate that this increasingly common disease frequently leads to a fatal outcome in patients requiring surgery and implies that earlier surgical consultation may be necessary to improve survival in patients with fulminating C. difficile colitis unresponsive to antibiotic therapy.

Between 1999 and 2003, meticillin-resistant Staphylococcus aureus (MRSA) isolates recovered from blood cultures in Irish hospitals that participate in the European Antimicrobial Resistance Surveillance System were investigated by epidemiological typing using antibiogram–resistogram (AR) typing, biotyping, and DNA macrorestriction digestion using SmaI followed by pulsed-field gel electrophoresis (PFGE). PFGE patterns were assigned five-digit pulsed-field type (PFT) numbers, and PFTs of apparently related patterns were abbreviated to two-digit PFT groups (PFGs). AR and PFGE typing results were combined to produce AR-PFG types. Representative isolates of each AR-PFG type recovered in 2002 were typed by multilocus sequence typing and staphylococcal cassette chromosome (SCC) mec analysis. Isolates from 1999 and 2000 were also typed by phage typing. The extent to which epidemiological types of MRSA from blood cultures could be extrapolated to the total MRSA population was investigated by comparing results obtained with isolates from the total MRSA population versus those obtained with blood cultures during three study periods. Over the 5 years from 1999 to 2003, 1,580 blood culture isolates from 1,495 patients were analysed. Typeability and discriminatory indices were as follows: AR typing, 1 and 0.97; phage typing, 0.29 and 0.89; PFGE, 0.99 and 0.95; AR-PFG typing, 1 and 0.95. The most frequently occurring AR-PFG types were 06-01, 07-02, 13-00, and 14-00 and were exhibited by 57, 7, 14, and 12% of isolates, respectively. During the study period, the distribution of AR-PFG type changed markedly, with the prevalence of one type (AR-PFG 06-01) increasing by 880%, from 22% (39/181) in 1999 to 80% (343/430) in 2003. Investigation of whether epidemiological types among blood culture isolates of MRSA were representative of the total MRSA population showed that there was no significant difference in most instances. MLST and SCCmec typing showed that AR-PFG types 06-01, 07-02, 13-00, and 14-00 were ST22–MRSA-IV, ST36–MRSA-II, ST8–MRSA-IID, and ST8–MRSA-IIE, respectively.

Since the early 1980s the reports of infection and illness associated withEscherichia coli 0157:H7 have increased dramatically worldwide, and particularly in the USA, Canada and UK. The spectrum of disease varies from asymptomatic carriage to haemorrhagic colitis and haemolytic uraemic syndrome (HUS). This infection is new to Ireland, and we report on 2 cases of isolation which outline the presentation of this organism with haemorrhagic colitis and HUS.

Presented here is the 5-year impact of a national antimicrobial resistance surveillance system in Ireland, which was introduced in accordance with the European Antimicrobial Resistance Surveillance System (EARSS). Participation in EARSS began in Ireland in 1999. Initially, 12 laboratories serving a mix of general and tertiary hospitals participated, but by 2003, participation had increased to 28 laboratories with a population coverage of 89%. During 1999-2003, 4,146 episodes of Staphylococcus aureus bacteraemia were reported, and methicillin resistance was detected in 1,709 (41.2%) of these isolates. Over the same period, 1,245 invasive (blood or cerebrospinal fluid) episodes of Streptococcus pneumoniae infection were reported, and 160 (12.9%) isolates were found to be non-susceptible to penicillin, with 23 (1.8%) demonstrating high-level penicillin resistance. By 2003, most Irish hospitals were participating in EARSS, which has been a catalyst for the development of a national antimicrobial resistance surveillance programme.

In order to evaluate the diagnostic usefulness of Gram-staining films from petechial lesions in suspected meningococcal infection, data from 52 patients with confirmed infection were reviewed. Gram-negative diplococci were found in specimens from skin films in 80% (24/30) patients with petechiae. This is significantly better than results reported for Gram-staining of needle aspirates from petechiae (46%; 12/26). Positive skin films were obtained from 89% (17/19) blood culture negative cases and 85% (17/20) CSF negative cases. In 14 cases meningococcal infection was identified only by skin films. Skin film results were not significantly affected by previous antibiotic. Gram-staining of films from petechial lesions in suspected meningococcal infection is a very rapid and effective investigation. Blood culture, CSF examination and culture, and skin films each identified meningococcal infection not identified by the other two investigations.

Admissions to Irish hospitals from nursing homes are recognized as a high-risk category for methicillin-resistant Staphylococcus aureus (MRSA) colonization. This study was conducted between August 1994 and May 1995 to determine the prevalence of MRSA within six Eastern Health Board elderly care nursing homes. A point prevalence survey was conducted in each home on two separate occasions at an interval of five to six months. An MRSA prevalence rate of 8.6% (65 of 754 residents) was recorded for the first survey, and an increased prevalence rate 10.1% (75 of 743 residents) for the second. The prevalence rates within individual homes varied from 1-27%. The body site most commonly colonized was the nares (83%), as anticipated. The main unexpected finding was a low wound colonization rate of 12%, which increased to only 20%, among MRSA positive residents. The dynamic state of MRSA colonization within nursing homes was documented among the 587 residents screened in both surveys. The MRSA positive status of 19 residents remained unchanged, but 32 who were initially positive became negative, while 34 residents acquired the organism. Twenty-six of the 56 (46%) residents identified as MRSA positive in the second survey had acquired the organism within the nursing home over the preceding five to six months. These findings suggest that 'infection control' interventions could have a significant impact on MRSA prevalence within nursing homes.

Risk factors predictive of methicillin-resistant Staphylococcus aureus (MRSA) colonization in 786 of 910 nursing home residents were evaluated. A customized questionnaire was completed by theresidents, who were screened for MRSA. The risk factors significantly associated with MRSA colonization were male sex, age >80 years, residence in the nursing home for

There have been increasing reports worldwide of vancomycin resistant enterococci (VRE) since they were first noted over ten years ago. This study sought to investigate the clinical significance of VRE in Ireland and to compare the phenotypic, genotypic and molecular characteristics of isolates recovered from patients in different institutions. The relative contribution of inter-hospital transmission of strains to the dissemination of VRE in Ireland was assessed. Hospital surveillance for VRE is not well established in Ireland. The organism has been detected in seven hospitals. Detection has been predominantly in oncology inpatients in large tertiary referral hospitals in the Dublin metropolitan area in whom strains generally represent asymptomatic gastrointestinal tract colonization. The predominant species is E. faecium with the Van A resistance phenotype. Twenty-seven (87) of 31 isolates from one unit were shown to be of the same or closely related strain as were 10 (63%) of 16 from another unit, indicating significant nosocomial transmission within institutions. There was no evidence for inter-hospital transmission of VRE. VRE is established in Ireland and nosocomial transmission readily occurs. Regular surveillance for VRE is indicated in high-risk populations in large institutions, specific risk factors for the acquisition of VRE need to be defined and optimal control and preventative strategies need to he instituted to detect and preempt the spread of this organism.

An outbreak of multi-resistant Serratia marcescens involving 24 patients occurred in a bone marrow transplant and oncology unit, from September 1998 to June 1999, of whom 14 developed serious infection. This is the first such outbreak described in a BMT unit. All isolates demonstrated the same antimicrobial susceptibility pattern and were the same unusual serotype O21:K14. The antimicrobial susceptibility profile showed reduced susceptibility to ciprofloxacin, gentamicin and piperacillin-tazobactam. As the latter two antimicrobials are part of our empiric therapy for febrile neutropenia, they were substituted with meropenem and amikacin during the outbreak. Investigation revealed breaches in infection control practices. Subsequently, the outbreak was contained following implementation of strict infection control measures. A prominent feature of the outbreak was prolonged carriage in some patients. These patients may have acted as reservoirs for cross-infection. This report also indicates that patients who become colonised with Serratia marcescens may subsequently develop invasive infection during neutropenic periods. Bone Marrow Transplantation (2000) 25, 873–877.

Clostridium difficile -associated disease (CDAD) is primarily a nosocomial condition. Community-acquired disease has been reported but the incidence is felt to be low and the rate of disease resulting in hospitalization is reported as negligible. We recently experienced a 6-month outbreak of CDAD (January to June 1995): 139 patients were involved and four deaths were attributable to pseudomembranous colitis. Early in the outbreak period we were aware that many new admissions presented with C. difficile cytotoxin B positive diarrhoea: in some cases this was the sole reason for hospitalization. This observation forms the basis of this report.

We describe a serious outbreak of infection caused by a strain of Serratia marcescens in two Dublin hospitals which occurred over an 11 week period and affected a total of 15 patients. A contaminated bed-pan macerator in the Intensive Care Unit of one hospital was identified as the possible source of infection and spread of the organism probably occurred via hand transmission by hospital personnel and via patient transfer to a second hospital. All isolates of S. marcescens involved in the outbreak had the same antimicrobial susceptibility pattern, with reduced susceptibility to gentamicin, cefotaxime and ciprofloxacin. Epidemiological typing revealed that the strains of S. marcescens isolated in the outbreak were of an uncommon serotype, O21:K14, and using pulsed-field gel electrophoresis, XbaI DNA macrorestriction profiles clustered at 90% similarity. The DNA patterns of the outbreak strain were also highly similar to S. marcescens isolates of the same serotype recovered from a separate Dublin hospital during the same time period as the outbreak described here. In addition, the isolates clustered at 82% similarity with strains of the same serotype from a retrospective collection of S. marcescens isolates from various hospitals in the Dublin area, indicating that these may be genetic variants of the same strain. Although the outbreak was brought under control following implementation of infection control measures, a significant number of similar O:21 isolates of S. marcescens have since been identified in four Dublin hospitals. These results suggest the unique spread of a single strain of S. marcescens in Dublin hospitals.

Mucormycosis is an uncommon severe life-threatening fungal infection in the immunocompromised host caused by fungi belonging to the order Mucorales, most commonly Rhizopus arrhizus (R. oryzae). We report a patient who developed a severe right atrial catheter exit site infection with Absidia corymbifera. The catheter was removed and necrotic tissue debrided. With liposomal amphotericin B and G-CSF, the infection subsided. He remains well 8 months later.

The Fc gammaR receptors for IgG, Fc gammaRI, Fc gammaRII and Fc gammaRIII were measured on neutrophils and monocytes from 36 patients suspected of systemic infection. These results were compared with 30 blood donor controls to assess the level of expression as an early indicator of bacterial infection. Fc gammaRI expression on neutrophils was found to be significantly increased from patients with systemic or localised infections, when compared to non-infected patient group, i.e., patients with no cultural evidence of bacterial infections, (p=0.02, p=0.04) or normal controls (p

Summary. An antibiogram-resistogram (AR) typing scheme that can simply and rapidly differentiate methicillin-resistant Staphylococcus aureus (MRSA) isolates has been devised. Susceptibility to antibiotics and chemicals was determined by disk diffusion testing. Three disk diffusion methods and three control S. aureus strains were evaluated. A modified Stokes' technique in which S. aureus ATCC 25923 replaced S. aureus NCTC 6571 as the control organism was chosen. Susceptibility patterns against 18 antibiotics and four chemicals were used to determine AR types. AR subtypes were determined with reference to knowledge of the local MRSA population so that plasmid loss would not result in misclassification. AR typing was compared with phage typing and plasmid profiling and found to be more discriminatory than either of these typing methods. Representative isolates of the most frequently occurring AR patterns were further characterised by investigating enterotoxin production, MICs of gentamicin and amikacin, and restriction endonuclease analysis of plasmid DNA, to determine whether apparently different strains could have the same AR pattern and to devise confirmatory tests for any such similar patterns. One pattern was shared by two strains but isolates could be differentiated by susceptibility to minocycline. This typing scheme can be used in the diagnostic laboratory and results may be obtained within 24 h.

Three methods, O-serotyping, phage typing and susceptibility to bacteriocins, were used to type 357 clinical isolates of Enterobacter cloacae cultured from 219 patients. One hundred and sixty isolates were typed by serology and phage typing. When these two methods were used, primary classification of isolates was based on serology (65.7% typable) and phage typing for further subdivision (94.1% typable). When all the isolates were typed by cloacin susceptibility, 81.5% of them were typable. Maximum discrimination between cultures was achieved when the three methods were used together; no single method was sufficiently discriminatory. There was a close parallel between serotyping and bacteriocin lysis pattern. The latter was easy to perform and the results were achieved within 48 h. By applying this typing system two episodes of cross-infection were identified in a haematology/oncology unit and intensive care unit.

SUMMARY Bile reflux gastritis occurs in the absence of Helicobacter pylori (H. pylori). The aim of this study was to see if the bile acids cheno or ursodeoxycholic acid affected the growth or adherence of H. pylori in vitro. Twenty-seven strains growth were inhibited by 0.1% chenodeoxycholic acid whereas only 11 out of the 27 were inhibited by 0.1% ursodeoxycholic acid. Growth was totally inhibited by a combination of 0.05 % chenodeoxycholic acid + 0.05 % ursodeoxycholic acid. Chenodeoxycholic acid was a more effective inhibitor of adherence in that the number inhibited and percentage inhibition were greater than with ursodeoxycholic acid. Bile salts might be useful in the treatment of H. pylori infection.

Methicillin-resistant Staphylococcus aureus (MRSA) has become an intractable problem in many hospitals in the world.’ There is an overall ambivalence about how we should respond to the presence of MRSA in our hospitals. Indeed, in a recent editorial on MRSA, Haley posed the question ‘do we just have to live with it?‘.’ It is the purpose of this paper to evaluate these microorganisms in relation to their virulence and genetic versatility and to identify strategies for their control in the 1990s.

Persistence of Helicobacter pylori after duodenal ulcer healing is associated with high rates of ulcer relapse. We compared colloidal bismuth subcitrate alone with CBS combined with one of four antibiotic regimens in the treatment of duodenal ulcers. Endoscopy and antral biopsies were performed before treatment and four weeks afterwards. Biopsy specimens were examined for histological evidence of gastritis and by Gram stain and culture for H pylori infection. Altogether 141 patients were allocated to one of five treatment groups. Giving CBS and metronidazole (400 mg tid for 7 days) with and without amoxycillin (500 mg tid) achieved higher clearance rates of H pylori than treatment with CBS alone (p less than 0.01). These two combinations also achieved higher rates of antral gastritis healing than CBS alone (p less than 0.01 and p less than 0.05 respectively). Susceptibility to metronidazole was tested in 29 isolates before and in seven isolates after treatment with metronidazole by disc diffusion test and minimum inhibitory concentration assay. Twenty seven (93%) of the isolates were sensitive before treatment while six of seven (86%) were resistant afterwards. Four of the six resistant strains had acquired resistance during treatment and one of these had acquired metronidazole resistance despite concomitant treatment with amoxycillin, to which it remained sensitive. CBS with adjuvant metronidazole at a dose of 400 mg tid for seven days significantly improves the eradication of H pylori compared with CBS alone. Acquired metronidazole resistance, however, seems to be an important cause of failure to eradicate H pylori.

Sixty consecutive patients with endoscopically proven duodenal ulcers were given colloidal bismuth subcitrate tablets either as 120 mg q.d.s. or 240 mg b.d., in a randomized single-blind study. The efficacy of each regimen was determined by endoscopic examination and antral biopsy at 4 weeks; if the ulcer remained unhealed, treatment was continued and endoscopy repeated at 8 weeks. The ulcer-healing efficacy of the two regimens was identical; however, in the four times daily group only 27% remained Campylobacter pylori positive after 8 weeks of treatment compared with 58% of the twice-daily group. Similarly, only 21% of twice daily patients were free of histological gastritis compared with 42% of the four times daily patients.

We report the spread of a methicillin- and gentamicin-resistant Staphylococcus aureus strain (MGRSA) from the Middle East and its subsequent dissemination within two hospitals in Dublin. The index case, a 30-year-old male with serious blast injuries was transferred from a Baghdad hospital to a Dublin hospital in May 1985. He was heavily infected with two MGRSA strains, one of which spread and was responsible for numerous episodes of nosocomial infection. This strain was very similar to MGRSA isolates recovered in a Baghdad hospital during 1984. This imported strain has now spread to two hospitals in our group causing sepsis. This report emphasizes the difficulty of detecting an imported strain in an endemic area, but above all points to the potential for spread when there is considerable movement of patients and personnel.

Editor-F Andrew I Riordan and colleagues report the diagnosis and treatment of early meningococcal disease in children in Liverpool.1 It is worth emphasising another aspect of these rashes–namely, that meningococci that are present in the rash may be identified by taking skin scrapings. The lesion is scraped with the point of a sterile needle until blood just starts to appear. The blood is then blotted on to microscope slides, allowed to dry, and examined …

THE frequency of methicillin resistant Staphylococcus aureus isolated from pathological material from eight Dublin hospitals between April, 1971 and April, 1972 was 5.4 per cent. This frequency justifies their routine detection.

Between 1972 and 1979 specimens from 241 patients grew Providencia stuartii . Details of 117 cases are reported. Most (77) of these were from urinary tract infections in male patients, over 30 years old (55) with some underlying urological disorder particularly prostatic hypertrophy and undergoing catheterization. In mixed infections (44) proteus was the most common species associated with Prov. stuartii . Escherichia coli was uncommon in comparison. Skin infections (37) occurred in burns and post-operative patients, and were mostly (31) mixed, with proteus and Pseudomonas aeruginosa as the most commonly associated Gram-negative rods. Three strains of Prov. stuartii were also cultured from sputa. Five cases of septicaemia occurred during the eight years reviewed with only one patient surviving. Isolates were mostly resistant to ampicillin, carbenicillin and gentamicin. Most (77117) were sensitive to kanamycin and all sensitive to amikacin and cefuroxime. Serological data showed one strain type accounting for 60% of the 117 isolates.

In a 6 week period, three of 50 patients developed Pseudomonas aeruginosa septicaemia following Endoscopic Retrograde Cholangiopancreatography (ERCP). Pseudomonas aeruginosa serotype 10 was isolated from each of the patients and from the endoscope. The outbreak was related to inadequate disinfection of the air and water channel of the endoscope. Following the introduction of a modified decontamination technique, which involved rinsing the air and water channel with glutaraldehyde, no further cases of pseudomonas infection occurred, and the organism could not be isolated from the instrument. Obstruction of the biliary tract was a predisposing factor in the development of infection; and administration of antibiotics immediately following the procedure failed to prevent it. This may have been due to inadequate dosage. We suggest that patients presenting for ERCP, in whom obstruction of the biliary tract is suspected, should come prepared for immediate drainage of the obstructed system at the time of the procedure.

Nasal carriage and antibiotic sensitivities of coagulase-positive and coagulase-negative staphylococci were assessed among medical students of three different years. Although carriage rates did not change, there was a trend towards multiple resistance with increasing hospital exposure. Gentamicin resistance in Staphylococcus albus showed a similar trend. The relevance of these findings to current views on the origin of gentamicin resistance is discussed.

Current chemotherapy for oncology (particularly leukaemia) patients had a profound suppressive effect on the bone marrow. The resulting periods of neutropenia vary in length but may be marked. Bodey et al. (1966) showed an inverse relationship between the incidence of infection and the absolute level of leukocytes; most bacteraemias occurred with granulocyte counts below 100 mmP3. Most infections arise from organisms in the upper respiratory or gastrointestinal tracts, but skin bacteria are of increasing importance. Damage to the skin or mucosa by cytotoxic therapy or insertion of vascular access devices such as Hickman catheters creates portals of entry for microbes. The latter are particularly associated with coagulase-negative staphylococci (CNS) (Wade et al. 1982). The extreme vulnerability of these patients had led to the institution of a variety of anti-infective measures. One of these measures is the use of surveillance cultures from various body sites. Specifically, these may indicate

We describe 10 patients with hospital-acquired osteomyelitis due to methicillin-resistant Staphylococcus aureus . The patients were post-traumatic and eight had a foreign body in situ at the site of infection. Vancomycin therapy in association with radical debridement was followed by clinical and radiological cure in eight patients at 2–3·5 years follow-up, in two of whom a foreign body was left in situ . Only minor adverse effects of vancomycin therapy (one rash, two thrombophlebitis) were seen.

Eighty-eight episodes of MRSA septicaemia occurring in 82 patients were studied prospectively. In 15 episodes bacteraemia was transient, in 36 non-fatal, in 33 fatal, while in four septicaemia was a major contributory factor in the patient's death. There were more patients aged over 60 years in the septicaemia groups compared to the transient bacteraemia group (P = 0.01), and patients with septicaemia were usually recently postoperative and/or suffering from severe underlying disease. Circulation access sites were the commonest source of the bacteraemic organisms with non-surgical wounds including burns, varicose ulcers and bed sores as the next most common. In four of the 16 burns patients, fatal septicaemia followed surgical debridement of infected burns. In only eight episodes was there no apparent source of bacteraemia.