Itching to know the diagnosis

Itching to know the diagnosis

Abstracts screening was negative. Carbapenem minimum inhibitory concentrations (MICs) were variable. Reduced susceptibility to these agents were attri...

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Abstracts screening was negative. Carbapenem minimum inhibitory concentrations (MICs) were variable. Reduced susceptibility to these agents were attributed to porin loss together with AmpC beta-lactamase production rather than carbapenemase production. No babies suffered a clinically significant infection, and only one positive was found on a clinical sample after the first three were identified. No clear source was found to account for the origin of the cluster.

Discussion The prevalence of neonates of extreme prematurity was unusually high, and therefore antibiotic (especially cephalosporin) usage was also high. At the outset of the cluster, there were two circulating strains. After a few months, these were replaced by predomninantly unique strains. This coincided with reduction in pressure on the unit, with fewer numbers of extremely premature infants. Carbapenem use on the unit was low, suggesting that the ertapenem resistance seen was in association with cephalosporin resistance and was a secondary effect. A review of E. cloacae isolates from NICU over 5 years revealed 8 similar isolates, possibly indicating a persisting low-level background presence.

Conclusions Screening appears to have highlighted what may be a natural phenomenon on the NICU, with E. cloacae present at a low level, and becoming more apparent under periods of stress on the unit. Further work may include the screening of other units using cephalosporins to see whether an unrecognised state of E. cloacae colonisation exists. Additionally, further work needs to be done on the association between hyperproduction of ampC beta-lactamase in E. cloacae, conferring resistance to cephalosporins, and concomitant porin loss conferring resistance to carbapenems. These results suggest that there may be a wider association than purely selection pressure from cephalosporin use.

EPIDEMIOLOGY OF EXTENDED SPECTRUM BETA LACTAMASES FROM BLOOD AND URINARY ISOLATES, COMPARING DETECTION BY DISC TESTING AND AN AUTOMATED METHODCATEGORY: SCIENTIFIC FREE PAPER Benjamin Cooke, Emma Hathorn, Kirstie Sharp, Amelia Tyers, John Coia, Brian Jones Glasgow Royal Infirmary, Glasgow, United Kingdom

e13 All urine samples submitted to Glasgow Royal Infirmary between 10th August and 11th September 2009 were tested for cefpodoxime resistance. Blood cultures were tested for ceftriaxone resistance. All resistant Gram-negative bacilli, (GNB), were tested for the presence of ESBL using the HPA standard disc synergy method. ESBL-positive isolates were then processed in the VITEK 2, to identify the organism and test antibiotic sensitivity. The rates of correct ESBL detection by the automated method were recorded, and the epidemiology of the isolates investigated. The reporting of cephalosporin sensitivity by the VITEK 2 was assessed. The rates of sensitivity to gentamicin and MeropenemÒ, which can be used therapeutically in the presence of an ESBL, were established.

Scientific findings 15,286 urine samples were submitted over the study period, and 3284 grew a GNB. The majority of urinary ESBLs were isolated from patients over 65 years (141 isolates, 77.9%). 95 Blood cultures grew GNB, 4 of which were ESBL positive, (4.3%). A sample of 69 ESBL-positive isolates was available for comparison with automated ESBL detection by VITEK 2. Of 65 urine ESBLs, 8 were Klebsiella spp, one was an Enterobacter and 55 were E. coli. The VITEK 2 correctly identified 66 of the ESBLs, (95.7%). 35 of the ESBLs were sensitive to gentamicin, (50.7%), and all were sensitive to MeropenemÒ.

Discussion The Advanced Expert System of the VITEK 2 correctly reported cefotaxime as resistant(R) or intermediate (I) in 67, (97%) of ESBL positive isolates. The 2 samples it reported sensitive were those it identified as penicillinase producers. It reported ceftazidime as R/I in 94.2%. Piperacillin/tazobactam use to treat ESBL-associated infections is controversial. Sensitivity testing results are not altered in the presence of an ESBL by the VITEK 2. 61 ESBL positive GNB were reported as sensitive to piperacillin/tazobactam, (88.4%).

Conclusions ESBLs account for 5.5% of urinary GNB in Glasgow. They are more common in the elderly and from catheter samples. The VITEK 2 identifies ESBL with 95.7% sensitivity, and appropriately reports cephalosporin sensitivity 94.2% of the time. Clinical microbiology input is thus still required when authorising results from this automated system.

Introduction This study looked at the epidemiology of ESBLs isolated from urine and blood samples submitted to a large diagnostic laboratory. The standard HPA detection method, (QSOP 51), was compared with an automated method rieux). (VITEK 2, bioMe

ITCHING TO KNOW THE DIAGNOSISCATEGORY: LESSON IN MICROBIOLOGY & INFECTION CONTROL Chloe Keane, Alistair Leanord Southern General Hospital, Glasgow, United Kingdom

e14

Abstracts

Introduction

Conclusions

A normally healthy 22 year old male presented to our hospital with a two day history of unbearably itchy hands and feet. Although this was his main complaint, he had also noticed the development of a widespread rash over the last 24 hours and had been feverish with rigors overnight. He additionally complained of a mild sore throat, and of a chronic "ingrown hair" at the natal cleft which had become more painful recently. On examination, he had a 3cm wide pilonidal abscess. A macular blanching rash was present on the patient’s hands, feet, forearms, and abdomen. Despite complaining of a sore throat, his throat looked normal. Observations taken in A&E showed that he was pyrexial and tachycardic. At this point, his rash was thought to be viral in nature, but in view of his sepsis he was commenced on intravenous antibiotics (amoxicillin, gentamicin and metronidazole). He underwent an uneventful incision and drainage of his pilonidal abscess that evening. However, his antibiotics were stopped immediately post-operatively. Later that night, his condition worsened and he developed multi-organ failure (MOF) and septic shock. His temperature rose steeply to 39.8C, blood pressure dropped to 83/35mmHg, and urine output stopped. At this point, a diagnosis of toxic shock syndrome was considered, and the patient was commenced on a different combination of intravenous antibiotics (benzylpenicillin, flucloxacillin, clindamycin, gentamicin and metronidazole). He steadily improved on this antibiotic regime, and was discharged home 8 days later with a further 7 days of oral flucloxacillin and clindamycin.

This was an unusual case of staphylococcal TSS presenting with itchy hands. However, the patient’s widespread rash, presence of an abscess, and sepsis, pointed at the onset to possible toxic shock syndrome. As the patient’s condition deteriorated and MOF and shock developed, this diagnosis became much more likely. Current treatment recommendations for staphylococcal TSS are to use an antibiotic which suppresses toxin production, such as clindamycin or linezolid, together with flucloxacillin. Intravenous immunoglobulin theoretically has the potential to neutralise superantigen, and is recommended for use in cases where there is failure to improve despite aggressive support and source control.

Scientific findings The only positive microbiology finding in this case was from the pilonidal pus sample taken intra-operatively. This grew a mixture of anaerobes, and Staphylococcus aureus which was sensitive to flucloxacillin and clindamycin. The S. aureus isolate was sent to our hospital’s reference laboratory for additional toxin testing. PCR was used to detect nine staphylococcal toxin genes: 5 enterotoxin genes (sea, seb, sec, sed, and see), 2 exfoliative toxins (eta and etb), Toxic Shock Syndrome-Toxin 1 (TSST-1), and the Panton-Valentine Leukocidin (PVL) gene. The gene for TSST-1 was detected. Blood cultures and a throat swab were negative.

Discussion Although the gene for TSST-1 was detected in this S. aureus isolate, it is impossible to know whether this gene was being expressed in vivo. In vitro tests involving culture and detection of the formed TSST-1 protein by ELISA or Western blot could have been done, but were not performed in this case. Serological testing for antibodies to TSST-1 is probably unhelpful, as previous studies have shown an association between toxic shock syndrome (TSS) and the inability of affected patients to form antibodies against the superantigens. Blood cultures are negative in most cases (>95%) of staphylococcal TSS.

AN AUDIT ON DEATH CERTIFICATIONS AND CLOSTRIDIUM DIFFICILE INFECTION AT COUNTY DURHAM AND DARLINGTON NHS TRUSTCATEGORY: LESSON IN MICROBIOLOGY & INFECTION CONTROL Veena Raviprakash, John Sloss Darlington Memorial Hospital, Darlington, United Kingdom

Introduction Death certification provides information about mortality associated with different diseases to clinicians,realtives and health services managers . It is the legal responsibility of the medical professionals to ensure that the certificate accurately reflects the sequence of events leading to death. Clostridium difficile is the most common bacterial cause of hospital-acquired diarrhea. In severe cases, leads to pseudo membranous colitis and sometimes death. There is a public concern about healthcare associated infections (HCAIs) as the cause or contributory factor to death and a belief that the doctors are reluctant to put information about HCAIs on the death certificates.There is also a widespread belief among the public that the figures underestimate the mortality.The department of health guidelines published in Dec 2008 states that Medical directors should ensure training is provided on death certification .It also states that the death certificates should be audited that they accurately record HCAI.Hence this Audit was undertaken to establish the local practice in doing the death certificates and devise a plan of action to over come the shortfalls. In this trust all patients who die with C diff diarrhoea are reviewed by Microbiologist who systematically analyses the events leading to the death of the patient and compares with the death certificate and write a report to the Clinical risk manager .This audit was carried out by looking at these letters and comparing with the death certificates.Retrospective Audit of 68 patients who died in the Hospital between 1/01/ 2008 and 31/12/2008 who were found to be having C. diff diarrhoea.