The clinical spectrum of Lyme neuroborreliosis.

Lyme disease is a multisystem infectious disease, endemic in parts of Europe, including the West of Ireland. Neurological manifestions (neuroborreliosis) are variable. Presenting neurological syndromes include meningitis, cranial neuropathies, myeloradiculitis and mononeuritis multiplex. A lack of specificity in serological diagnosis may add to diagnostic confusion. We reviewed thirty cases of acute Lyme disease in the West of Ireland and found neurological syndromes in 15 (50%), with painful radiculopathy (12 patients; 80%) and cranial neuropathy (7 patients; 46%) occurring frequently. Neuroborreliosis needs to be considered in the differential diagnosis of these neurological syndromes in the appropriate clinical context.

Clonal expansion may account for high levels of quinolone resistance in Salmonella enterica serovar enteritidis.

We have observed a high incidence of isolated nalidixic acid resistance in Salmonella enterica serovar Enteritidis isolates in Ireland, particularly isolates of phage type 1 (PT1). A group of nalidixic acid-resistant (n = 22) and nalidixic acid-susceptible (n = 28) isolates of serovar Enteritidis from multiple sites in Ireland were selected. Isolates were typed by pulsed-field gel electrophoresis (PFGE) with XbaI, and the MICs for nalidixic acid and ciprofloxacin were determined. Mutations associated with nalidixic acid resistance in clinical isolates and laboratory mutants of serovar Enteritidis and 32 nalidixic acid-resistant isolates of 15 other salmonella serovars were identified. PFGE had limited discriminatory power. A specific point mutation (G246T) associated with amino acid substitution Asp87Tyr in the quinolone resistance determining region of the gyrA gene accounted for 95% of all mutations in serovar Enteritidis and for all mutations in PT1 isolates. Greater diversity of mutations was observed among all non-Enteritidis salmonella serovars studied. Rates of nalidixic acid resistance in serovar Enteritidis may predominantly reflect clonal expansion after infrequent mutation or selection events.

Antimicrobial resistance in E.coli associated with urinary tract infection in the west of Ireland.

BACKGROUND: Knowledge of antimicrobial resistance patterns in E. coli, the predominant pathogen associated with urinary tract infection (UTI) is important as a guide in selecting empirical antimicrobial therapy AIMS: To describe the antimicrobial susceptibility of E. coli associated with UTI in a region in the West of Ireland. METHODS: A collection of 934 E. coli isolates associated with UTI were tested for susceptibility to a panel of antimicrobial agents by the disc diffusion method of the National Committee for Clinical Laboratory Standards. RESULTS: More than 50% of E. coli were resistant to ampicillin, more than 40% resistant to sulphonamide and more than 30% resistant to trimethoprim. From 7.9% (community) to 12.5% (hospital) are resistant to co-amoxiclav with approximately 20% of isolates of intermediate susceptibility. In general practice most E. coli remain susceptible to nitrofurantoin (96.7%), nalidixic acid (93.9%) and ciprofloxacin (94.7%). For all agents rates of resistance were higher in hospital as compared with general practice isolates. Three isolates with the phenotype of Extended Spectrum Beta-lactamase (ESBL) resistance were detected. CONCLUSIONS: Ampicillin/amoxicillin are not suitable for empiric therapy of UTI in general practice or hospital patients in this region. There is doubt as to the role of trimethorpim or co-trimoxazole for empiric therapy of UTI. Nitrofurantoin, nalidixic acid and ciprofloxacin are active against the great majority of UTI associated E. coli.

Antimicrobial resistance and phage types of human and non-human Salmonella enterica isolates in Ireland, 1998-2003.

Between 1998 and 2003, 5,161 isolates (3,182 human) of Salmonella enterica were received by the National Salmonella Reference Laboratory of Ireland. Serotyping, antimicrobial susceptibility testing and phage typing were performed by standard methods. The number of isolates of S. enterica serovar Typhimurium decreased from 579 (80%) in 1998 to 208 (19%) in 2003, while S. enterica serovar Enteritidis increased from 59 (8%) in 1998 to 219 (20%) in 2003. Definitive (DT) phage types 104 and DT104b accounted for a declining proportion of all Salmonella Typhimurium isolates (from n = 523 [90%] in 1998 to 126 [60%] in 2003). Numbers of Salmonella Enteritidis phage type 4 declined from 50 (85%) in 1998 to 59 (27%) in 2003. Twenty-eight isolates of typhoidal Salmonella were received with a history of recent travel in 17 cases. Resistance to multiple (four or more) antimicrobial agents was related to serotype and, where applicable, phage type, and was common in Salmonella Typhimurium. Salmonella Typhimurium predominated among isolates from cattle and pigs (n = 213 [58%]), while Salmonella Livingstone (n = 327) and S. Kentucky (n = 227) were predominant in isolates from poultry (total n = 554 [43%]). This paper discusses trends, and their implications, in Irish salmonella isolates since the establishment of the Reference Laboratory.

Antimicrobial resistance and genetic diversity of Shigella sonnei isolates from western Ireland, an area of low incidence of infection.

Shigella sonnei is a significant cause of gastroenteritis in both developing and industrialized countries. Definition of the diversity and antimicrobial susceptibility of S. sonnei isolates may be helpful in the management of individual cases and outbreaks. Antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE) were performed with 67 isolates of S. sonnei predominantly (n = 59) from three counties in the west of Ireland. Phage typing (n = 17), plasmid profiling (n = 28), and integron analysis (n = 24) were performed with subsets of strains. PFGE typing permitted recognition of two major clusters: PFGE type A (n = 53) and PFGE type B (n = 14). PFGE type A was associated with resistance to ampicillin, streptomycin, and sulfonamides (51 of 53 isolates), and those that were phage typed (n = 6) were phage type 3. PFGE type B was associated with resistance to streptomycin, sulfonamides, tetracycline, and trimethoprim (11 of 14 isolates) and phage type 6 (9 of 11 isolates). Fifteen different plasmid profiles were identified among the 28 isolates analyzed. A class 2 integron was present in all 14 PFGE type B isolates. One of these isolates also contained a class 1 integron and showed a unique variant of the PFGE type B pattern. Sequence analysis of the gene cassette structures contained within these integrons identified distinct open reading frames that encoded determinants of resistance to trimethoprim, streptomycin, and streptothricin. Our data demonstrate two predominant PFGE types among S. sonnei isolates circulating in this region. The limited diversity of the S. sonnei isolates in this region means that detection of isolates indistinguishable by PFGE and according to their antibiograms in two or more patients is not persuasive evidence of a common-source food- or waterborne outbreak. Indistinguishable plasmid profiles in addition to indistinguishable PFGE and antibiogram types may be more suggestive of an epidemiologically relevant link between cases.

Soft tissue infection with Absidia corymbifera in a patient with idiopathic aplastic anemia.

We describe a case of primary cutaneous mucormycosis (zygomycosis) in a patient with idiopathic aplastic anemia which responded to surgical debridement and therapy with liposomal amphotericin B. The tissue removed at surgery showed dense infiltration with fungal hyphae on histopathological examination. Primary cultures of tissue on solid media were negative, but Absidia corymbifera was isolated from unprocessed tissue placed in brain heart infusion broth.

Evaluation of methods for detection of toxins in specimens of feces submitted for diagnosis of Clostridium difficile-associated diarrhea.

Clostridium difficile is the principal pathogen associated with hospital-acquired acute diarrheal disease. We have evaluated the performances of six approaches for diagnosis of C. difficile-associated diarrhea (CDAD). Consecutive stool specimens (n = 200) from 133 patients were examined by cytotoxin assay, by culture of C. difficile on cycloserine-cefoxitin-fructose agar, and by toxin detection using four rapid immunoassay systems (Oxoid Toxin A test, ImmunoCard Toxin A test, TechLab Tox A/B II test, and Premier Toxins A&B test). A diagnosis of CDAD was established for 35 (27%) patients (representing 29% of specimens). The adjusted sensitivity and specificity of the methods were, respectively, 98 and 99% for the cytotoxin assay, 54 and 99% for ImmunoCard, 50 and 98% for Oxoid, 79 and 98% for TechLab, 80 and 98% for Premier, and 57 and 100% for culture. The TechLab and Premier assays are acceptable tests for diagnosis of CDAD but are not equivalent to the cytotoxin assay.

Comparison of BACTEC MGIT 960 and BACTEC 460 for culture of Mycobacteria.

We have compared the BACTEC 460 system with the BACTEC MGIT 960 system for culture of mycobacteria from 1800 routine clinical specimens. Rate of isolation of M. tuberculosis and time to detection of positive culture was comparable for both systems (BACTEC 460, 35 isolates, BACTEC MGIT 960, 34 isolates). Contamination of cultures was more common with the BACTEC MGIT 960 system. With intensification of the decontamination process an acceptable contamination rate was achieved in the BACTEC MGIT 960 system but time to detection of positive culture was increased by 1 to 2 days.

Cost-effective methods for isolation of Salmonella enterica in the clinical laboratory.

Data from 8,717 fecal specimens indicate that primary inoculation of xylose lysine deoxycholate (XLD) agar may enhance the speed, but not the sensitivity, of isolation of Salmonella enterica over that achieved with Selenite enrichment only. Plating of Selenite broth onto both brilliant green and XLD agar offers no advantage over plating onto XLD alone.

The use of pulsed-field gel electrophoresis for subdivision of Salmonella typhimurium in an outbreak situation.

An institutional outbreak of gastroenteritis provided an opportunity to investigate further the isolates of Salmonella typhimurium by pulsed-field gel electrophoresis (PFGE). Three phage types were identified. Antibiograms identified two types and two distinct patterns were found on PFGE. If phage typing alone is used for epidemiological study of strains, it is possible that an association between strains may be missed.

In-vitro activity of piperacillin/tazobactam relative to other antibiotics against blood culture isolates.

Resistance of bacteria to antibiotics is an increasing problem in many countries. Accurate locally relevant information is essential for detection and control of emerging resistance and to facilitate choice of empirical antibiotic therapy in the immediate management of seriously ill patients. We have determined the minimum inhibitory concentration of piperacillin/tazobactam for 97 strains of bacteria (55 Enterobacteriaceae, 13 non-fermentative Gram-negative bacilli, 22 Staphylococcus aureus, 6 Enterococcus faecalis and 1 Bacillus cereus) isolated from blood cultures and compared its activity to that of amoxycillin, co-amoxiclav, cephalothin, cefotaxime, ceftazidime, ciprofloxacin, gentamicin, piperacillin, cefotaxime. The strains were consecutive non-fastidious isolates with the following qualifications: coagulase negative staphylococci and diphtheroids were excluded and the number of Staphylococcus aureus isolates was limited to 12 methicillin-resistant and 10 methicillin-sensitive strains. Multiple isolates of the same species from individual patients were not included. The minimum inhibition concentrations of methicillin, penicillin, teichoplanin and vancomycin were also determined for specific groups of organisms. MICs were determined by the Etest method (AB Biodisk, Solna, Sweden) on Mueller Hinton agar. The MICs of appropriate American Type Culture Collection control strains were determined. Based on the interpretative criteria of the National Committee for Clinical Laboratory Standards (USA), 87 per cent of Gram-negative bacilli were susceptible to piperacillin/tazobactam compared with amoxycillin 26 per cent, cephalothin 35 per cent, co-amoxiclav 54 per cent, piperacillin 56 per cent, cefotaxime 69 per cent, ceftazidime 84 per cent, gentamicin 85 per cent and ciprofloxacin 91 per cent. Of all isolates 75 per cent were sensitive to piperacillin/tazobactam, compared with amoxycillin 22 per cent, cephalothin 35 per cent, piperacillin 41 per cent, co-amoxiclav 52 per cent, cefotaxime 59 per cent, ceftazidime 60 per cent, gentamicin 74 per cent and ciprofloxacin 77 per cent. Two isolates (1 E. coli and 1 Klebsiella pneumoniae) with antibiograms consistent with the relatively new resistance phenomenon of extended spectrum beta-lactamase production were identified. The spectrum of activity of piperacillin-tazobactam for empirical antibiotic therapy is significantly greater than that of piperacillin alone and is similar to that of ciprofloxacin and gentamicin.

A laboratory review of meningococcal infections in the west of Ireland.

A review of isolates of Neisseria meningitidis and other laboratory evidence of meningococcal infection was carried out for the period 1990-1995. Thirty-three patients with evidence of meningococcal disease were identified over the six year period. Group B organisms were the most commonly identified, but an increase in Group C has occurred and is almost equal in number. Data from clinical, laboratory and public health sources should be centralized in a National Surveillance Centre.

Prevalence of hepatitis C antibodies in patients with liver disorders in the west of Ireland.

During the period from August 1989 to October 1990, 93 patients living in the West of Ireland were screened for Hepatitis C antibodies (Anti HVC) using a commercially available assay. The tests were performed because of abnormal liver function tests (LFTs) or clinical suspicion of Hepatitis C. Nine positive results were obtained (10.3%) seven of whom had a history of transfusion of blood or a blood product. The study revealed that the prevalence of anti HCV was low in patients with chronic liver diseases, in comparison to reported prevalence rates in other parts of the world and that blood transfusion was the commonest predisposing factor to acquisition of anti HCV in this area.