Antibiotic susceptibility and molecular analysis of invasive Neisseria meningitidis recovered in the Republic of Ireland, 1996 to 2016.

This study examined the antimicrobial susceptibility of invasive meningococcal disease (IMD)-associated Neisseria meningitidis recovered in the Republic of Ireland between 1996 and 2016. In total, 1359 isolates representing over one-third of all laboratory-confirmed cases of IMD diagnosed each epidemiological year (EY; July 1-June 30) were analysed. All isolates were susceptible to ciprofloxacin, rifampicin and cefotaxime and 74% and 87% were susceptible to sulphonamide and penicillin, respectively. The proportion of isolates exhibiting reduced susceptibility to penicillin increased significantly during the study with no evidence of major clonal expansion or horizontal spread of a specific penA allele. Greater diversity observed among recently recovered meningococci and specifically among isolates exhibiting reduced penicillin susceptibility contributed to the overall increase in penA allele diversity throughout. The emergence and dissemination of strains with phenotypic and genotypic reduced susceptibility to penicillin increase the need for continued surveillance of antimicrobial susceptibility of meningococci in the Republic of Ireland especially in view of the recommendation of penicillin G as empiric treatment of choice for pre-hospital management.

A retrospective assessment of the completeness and timeliness of meningococcal disease notifications in the Republic of Ireland over a 16-year period, 1999-2015.

OBJECTIVES: To assess how invasive meningococcal disease (IMD) records held by the Irish Meningitis & Sepsis Reference Laboratory (IMSRL) compare to records of IMD notifications reported on the national integrated electronic Computerised Infectious Disease Reporting (CIDR) system. STUDY DESIGN: We assessed the completeness, data quality and timeliness of IMD notifications and reference laboratory records for the period between 01 July 1999 and 30 June 2015 by identifying discrepant and/or missing data items in a matched case data set and by measuring the timeliness of case reporting. METHODS: We matched anonymised cases notified to CIDR to records based at the IMSRL using birth, reporting and onset dates with gender and laboratory parameters of meningococcal strain characteristics and method of confirmation. Completeness, data quality and the timeliness of notifications were assessed by a stratified sensitivity-based technique and by calculating the average difference between IMSRL and CIDR reporting dates. RESULTS: CIDR recorded a total of 3163 notifications, of which 2759 (87.2%) were matched to IMSRL records. Completeness of IMD case classification as confirmed was estimated to be >99%. Examining the levels of discrepant or missing data in both matched CIDR and IMSRL records as a measure of data quality, recording of demographic items and meningococcal group showed least differences, recording of laboratory case confirmation method and meningococcal strain characteristics were less well recorded, with detail on clinical presentation/diagnosis least well recorded. Overall average annual difference between CIDR and IMSRL recording dates was 3.2 days (95% confidence interval 2.6-3.8). CONCLUSIONS: A high quality of IMD surveillance in Ireland was demonstrated, but scope for improvements in timeliness and capture of enhanced surveillance data regarding date of onset and strain-specific characteristics were identified.

An outbreak of influenza A in a neonatal intensive care unit.

OBJECTIVES: Investigation of an outbreak of influenza A in a neonatal intensive care unit (NICU) with examination of risk factors for infection and outcomes. DESIGN: Retrospective cohort study of infants admitted to the unit during the outbreak period. Prospective survey of NICU staff and mothers of infants in the cohort study. SETTING: Level III nursery in a university-affiliated tertiary referral center. RESULTS: Nineteen infants in the NICU were infected with influenza A There were six symptomatic cases and one death who had evidence of virus-associated hemophagocytic syndrome at autopsy. Amantadine prophylaxis was offered to the NICU staff, and amantadine therapy was given to five of the six symptomatic infants. Mechanical ventilation, gestational age, birth weight, Clinical Risk Index for Babies score, and twin pregnancy were associated with acquisition of influenza A on univariate analysis. Mechanical ventilation (odds ratio [OR], 6.2; P=.02) and twin pregnancy (OR, 7.0; P=.04) remained as significant risk factors for infection on multiple logistic regression analysis. Only 15% of respondents to the NICU staff survey were vaccinated against influenza. There was no association between a history of an influenza-like illness during pregnancy and acquisition of influenza A by infants of mothers who responded to the maternal survey (OR, 0.91; P=1.0). CONCLUSIONS: Influenza A is an important pathogen in the neonatal population and is readily transmissible in the NICU setting.

The impact of laboratory reporting practice on antibiotic utilisation.

Microbiology reports are often misinterpreted by clinicians, which may lead to inappropriate antibiotic prescribing. Restricted release of susceptibilities combined with interpretative comments, can have a positive impact on the level of appropriate antibiotic use. Such a system requires two-way communication between the laboratory and the clinician and the laboratory's reporting practices should encourage such communication. The production and transmission of clinically relevant microbiology reports should be an integral part of infectious disease management programmes in hospitals.

Investigation of an outbreak of gastroenteritis caused by Norwalk-like virus, using solid phase immune electron microscopy.

In February 1993, 95 persons (47 patients and 48 staff members) were affected by an hospital outbreak of viral gastroenteritis. Using direct electron microscopy (EM) the causative agent was identified as a small round structured virus. This was confirmed as a Norwalk-like virus using solid phase immune electron microscopy (SPIEM). Of 94 stool samples examined, 12 (13%) samples containing small round structured viruses (SRSV) were SPIEM positive for Norwalk-like virus. A further 25 (27%) samples contained small round featureless virus (SRFV) identified by direct EM and were negative on SPIEM. The illness was characterized by preceding influenza-like symptoms in 76% of cases followed by vomiting (76%), diarrhoea (79%) and abdominal pain (79%). One fatality was recorded. The outbreak lasted for 15 days, with a peak incidence of new cases amongst patients and staff occurring on day 5. It was controlled through a combination of ward closures, patient cohorting, suspension of duties for affected staff and disinfection procedures. Difficulties were encountered in the education of staff and in the implementation of environmental control measures. Screening of hospital catering services and a case control study, carried out among affected staff members, failed to identify a foodborne source. Consumption of tap water in the hospital was commoner among affected staff members than among controls, but this did not reach significance (P = 0.1).

Clostridium difficile colitis associated with chronic renal failure.

BACKGROUND: Clostridium difficile-associated diarrhoea (CDAD) is a potentially life-threatening illness which has been shown to be more common and more severe in patients with chronic renal failure (CRF) than in other groups. A review of CDAD in our nephrology unit was carried out. METHODS: A review of microbiology and histology records identified 32 cases of CDAD in the nephrology unit over a 24-month period. Patient notes were reviewed to identify risk factors, clinical features and outcome. Available isolates of C. difficile underwent 16S ribosomal RNA typing. RESULTS: The incidence of CDAD in the nephrology unit was 10.7 per 1000 admissions, compared to 2.7 per 1000 in other areas of the hospital (P<0.0001). CDAD was considered the sole or principal cause of death in six (19%) and was considered a contributing factor in a further seven (22%). Mortality was significantly higher among patients with established CRF (P=0.04). Seven cases occurred as a cluster, over a 1-month period. Isolates from this cluster, along with comparative strains from other areas of the hospital, were found to be PCR type 1. Diarrhoea occurred in 28 (89%) of cases, pyrexia in 17 (53%) and ileus or abdominal pain in 14 (44%). Six patients responded to discontinuation of antibiotics alone and 22 required metronidazole and/or vancomycin. Three patients had colectomy and one caecostomy because of toxic megacolon. Four patients died before specific therapy could be given and in two of these cases the diagnosis was made at autopsy. Twenty-six patients had a record of recent antibiotic therapy. Of these, 15 had at least one agent considered to be inappropriate (excessively broad spectrum agent in 11, excessive duration of therapy in four). Nine patients had only received antibiotics prior to admission. CONCLUSIONS: CDAD carries a high mortality in nephrology patients, especially those with established CRF. The diagnosis may be missed if a careful antibiotic history is not taken, including agents received prior to admission. Rational antibiotic prescribing and adherence to infection control measures are vital to reduce the incidence of this serious condition.

The impact of blood culture reporting and clinical liaison on the empiric treatment of bacteraemia.

AIMS: To assess the impact of blood culture results and early clinical liaison on the treatment of patients with bacteraemia. METHODS: 123 patients with significant positive blood cultures were followed over a nine month period in a 620 bed teaching hospital. The impact of early blood culture reporting and clinical liaison on the cost and appropriateness of treatment was assessed. RESULTS: Empiric treatment was started before the Gram stain result in 107 (87%) patients. Treatment was altered on the basis of the Gram stain result in 39 (36%) of these patients, and on culture and sensitivity results in 53 (50%). The spectrum of antibiotic treatment was narrowed in 58 (54%) of these; 20 (19%) on Gram stain result alone. This resulted in a 42% reduction in daily antibiotic costs in patients who had received empiric treatment. Empiric treatment did not follow the hospital antibiotic policy in 49 (46%) of the patients treated. In patients where empiric treatment was not in accordance with hospital policy, 21 (44%) had an isolate resistant to the empiric treatment used; while in patients who received agents in accordance with hospital policy only one (1.7%) had a resistant isolate (p < 0.05). Patients who died (11 (9%)) were less likely to have received empiric treatment in accordance with the antibiotic policy, although this did not reach statistical significance (p = 0.1). CONCLUSION: Early reporting of Gram stain results from blood cultures, combined with early clinical liaison, results in more rational and cost effective treatment.

The management of human bite injuries of the hand.

Human bites of the hand cause small wounds that are often incorrectly treated as "minor' injuries. We reviewed the management and outcome of patients with human bite or "punch' injuries of the hand. Significant morbidity resulted from late presentation and inadequate initial management. We propose a treatment protocol, in which all patients are immediately referred and admitted to hospital for surgical debridement.

Community and hospital acquired Staphylococcus aureus septicaemia: 115 cases from a Dublin teaching hospital.

Despite advances in diagnostic techniques and antimicrobials, septicaemia due to Staphylococcus aureus remains a common clinical problem with a significant mortality. We retrospectively compared community and hospital acquired cases of S. aureus septicaemia occurring in our 600 bed teaching hospital over a 30 month period. Of 110 episodes 32 (29%) were community acquired and 78 (71%) hospital acquired. A likely primary source was identified in 14 (44%) of community acquired cases and in 73 (94%) of hospital acquired cases. A secondary focus of infection was more common in community acquired cases (17, 53%) than hospital acquired cases (5, 6%). Mortality was significantly higher in community acquired cases (22% vs. 6%). An association was also found between the presence of endocarditis and increased mortality, although this did not reach significance. We also compared hospital acquired septicaemia due to methicillin sensitive and methicillin resistant S. aureus found a significantly higher mortality in the methicillin resistant group (22% vs. 3%, P < 0.05). S. aureus septicaemia remains an important cause of morbidity and mortality, particularly when associated with secondary foci of infection. This study also emphasises the importance of control of methicillin resistant strains in hospital.

The beneficial effects of immunostimulation in posttraumatic sepsis.

Granulocyte macrophage-colony stimulating factor (GM-CSF) is a myelopoietic cytokine that may enhance immune mechanisms directed against bacterial infection. Injury is associated with an increased incidence of such infection. This study assessed the potential immunostimulatory role of GM-CSF in the injured host predisposed to infection. Six- to eight-week old female CD-1 mice underwent trauma and were then randomized to received either GM-CSF or saline vehicle control intraperitoneally for 5 days. They then received a septic challenge in the form of a cecal ligation and puncture. Following this, assessment was made of survival and bacterial growth indices in blood cultures, and peritoneal cells were harvested for assessment of peritoneal immune function. Intraperitoneal GM-CSF administration daily for 5 days following injury was associated with significantly greater survival following cecal ligation and puncture compared to controls (40 vs 5%, P < 0.05). There was a significant increase in peritoneal cell yields in the GM-CSF group compared to the control group (11 +/- 1 x 10(6) vs 8 +/- 1 x 10(6) P < 0.05). PMA-stimulated macrophages released significantly higher amounts of both superoxide anion (1.4 +/- 0.1 vs 0.93 +/- 0.1, P < 0.05) and tumor necrosis factor (5.2 +/- 0.6 vs 2.6 +/- 0.7, P < 0.03) and significantly less nitric oxide compared to the control group (175 +/- 8 vs 267 +/- 24, P < 0.003). Finally, bacterial growth indices were significantly reduced following GM-CSF administration (194 +/- 6 vs 218 +/- 4, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary isolates of apramycin-resistant Escherichia coli and Klebsiella pneumoniae from Dublin.

Twenty-two gentamicin-resistant urinary isolates of Escherichia coli and five gentamicin-resistant urinary isolates of Klebsiella pneumoniae from a Dublin hospital were examined for resistance to the veterinary aminoglycoside antibiotic apramycin. Five isolates of E. coli and one isolate of K. pneumoniae were found to be resistant. The apramycin-resistant isolates, which were also resistant to the veterinary anthelmintic agent hygromycin B, hybridized with a DNA probe for the gene encoding the enzyme 3-N-aminoglycoside acetyltransferase type IV (AAC(3)IV). Resistance to apramycin and hygromycin B was co-transferable in four of the five isolates of E. coli and the isolate of K. pneumoniae. In one isolate of E. coli apramycin resistance was not transferable. On the basis of their restriction enzyme digestion profiles and the antimicrobial resistance traits encoded, the transferable plasmids encoding resistance to apramycin and hygromycin B comprised three distinct types. Genetic linkage between the gene encoding AAC(3)IV and genes encoding resistance to ampicillin and either tetracycline or trimethoprim, means that the relatively widespread use of these antimicrobial agents provides a selective pressure for the persistence of resistance to apramycin and gentamicin even in the absence of bacterial exposure to aminoglycosides.

Experience with Enterobacter bacteraemia in a Dublin teaching hospital.

In a review of Enterobacter bacteraemia in a 600-bedded teaching hospital, 22 episodes were identified in 20 patients over a 2-year period. An evaluation of risk factors suggested an association between Enterobacter infection and the presence of central venous catheters or use of H-2 receptor antagonists. These factors together with previous exposure of the patient to gentamicin, and prolonged stay in the intensive care unit, increased the likelihood of gentamicin-resistant Enterobacter bacteraemia. This finding has implications for the choice of antibiotic regimen in the empirical treatment of suspected Gram-negative septicaemia.

Susceptibility of urinary pathogens in a Dublin teaching hospital.

The range and resistance patterns of organisms causing urinary tract infections (UTI) vary with time and place. A prospective study of midstream urine (MSU) specimens, received over a 3 month period, was therefore undertaken. The antibiotic sensitivities of 528 isolates from 196 domiciliary and 332 hospitalised patients with significant bacteriuria (> 10(5) organisms/ml) were determined using the modified Stokes method. Escherichia coli accounted for 79% of domiciliary isolates and 57% in hospitalised patients. Gram positive organisms causing UTI have become increasingly common and were isolated from 8% and 15% of domiciliary and hospitalised patients respectively. Resistance levels for co-amoxiclav (Augmentin) were low (7% domiciliary, 14% hospitalised). However 46 Gram negative isolates (10%) had intermediate sensitivities to co-amoxiclav on disc testing. Breakpoint testing showed 89% of these to be sensitive at the urinary breakpoint but only 52% were sensitive at the systemic breakpoint. Forty nine percent of E. coli from hospital specimens were resistant to pipercillin, due to TEM-1 beta lactamase production. A 6% resistance level to ciprofloxacin in domiciliary E. coli is considerably higher than previous reports and gives cause for concern. Gentamicin resistance was found in 4% of Gram negative hospital isolates, a finding of some significance in the empiric treatment of septicaemia of urinary tract origin.