Inter-laboratory variability of caspofungin MICs for Nakaseomyces glabrata isolates - an Irish tertiary hospital experience

Background

Nakaseomyces glabrata, formerly Candida glabrata, is an opportunistic yeast and emerging cause of human infections. The use of broth microdilution (BMD) methodologies for caspofungin (CSP) antifungal susceptibility testing (AFST) against N. glabrata is reported to be prone to high inter-laboratory variation. We aimed to compare CSP MICs of N. glabrata isolates from our institution with those obtained by the Reference Laboratory for the same isolates.

Methods

All clinically significant N. glabrata isolates from 2019 to 2021 inclusive were reviewed. AFST was performed locally using the VITEK2 system with the AST-YS08 card, while E-tests were performed at the Mycology Reference Laboratory (MRL), and agreement between these two methods was evaluated - categorical and essential.

Results

Forty-one isolates were reviewed during the study period - 30 from blood cultures, seven from intra-operative theatre specimens and four from sterile site drain fluids. Despite an essential agreement of 100 % within ±2 log2 dilutions, marked discrepancies were noted in interpretative breakpoints between assays with 17 Minor and 16 Major category errors. Categorical agreement was 19.5 %, with the VITEK2 over-estimating resistance. A Mann-Whitney U-test assessed the relationship of MICs across the AFST modalities, and a statistically significant difference was noted, P<0.01, with a higher mean rank for VITKEK2 outputs.

Conclusion

While the VITEK2 system is highly applicable, its performance for CSP AFST is unreliable and potentially results in the mis-classification of susceptible isolates as highlighted in our study. The use of VITEK2 AST-YS08 micafungin as a sentinel echinocandin should be explored and/or the evaluation of CSP-specific E-tests as utilized by the MRL. These methods appear more consistent and less prone to the variation seen with BMD for CSP.

Antimicrobial Susceptibility Patterns of Anaerobic Bacteria at an Irish University Hospital over the past Decade

Background

Various studies have demonstrated poor outcomes in infections caused by anaerobic bacteria due to inappropriate therapy, directly due to emergence of resistant strains. To date there is a paucity of available data on antimicrobial resistance trends of anaerobic bacteria among the Irish population, and our study aims to determine such patterns among isolates processed at our institution over the previous decade.

Methodology

Selected anaerobic bacteria isolated from clinical specimens processed at our laboratory from January 2010 to January 2020 inclusive were collected and studied. Bacteria were identified using MALDI-TOF, with VITEK and E-tests for antimicrobial susceptibility testing. Data was processed through WHONET.

Results

A total of 2098 clinically significant anaerobic bacterial isolates were reviewed during the study period; with the majority of isolates being Bacteroides spp (32.79%, n=688) and Clostridium spp (18.68%, n=392). Bacteroides spp and Prevotella spp were unsurprisingly highly penicillin-resistant at 98.8% (n=680) and 77% (n=114) respectively. Resistance rates against metronidazole were expectedly high amongst Propionibacterium spp (100%, n=341), Actinomyces spp (98.8%, n=79), Lactobacillus spp (59.7%, n=95) and Bifidobacterium spp (53.8%, n=7); whilst remaining anaerobes were largely susceptibility. All isolates were particularly susceptible to co-amoxiclav, piperacillin-tazobactam and meropenem. Clindamycin exhibited a more variable susceptibility pattern, from 6.7% resistance in Staphylococcus saccharolyticus to 81.1% resistance in Prevotella spp.

Conclusion

Metronidazole and beta-lactams remain highly efficacious against the majority of anaerobic isolates reviewed, and remain the backbone of empiric therapy in suspected infections. However, it remains important for periodic surveillance of resistance trends.

Antimicrobial susceptibility patterns of anaerobic bacteria at an Irish University Hospital over a ten-year period (2010-2020)

OBJECTIVES

In recent years various clinical studies have demonstrated poor outcomes in infections caused by anaerobic bacteria due to inappropriate therapy, directly due to emergence of resistant strains. This is a concern given that many anaerobic infections are treated empirically with metronidazole or a beta-lactam/beta-lactamase inhibitor combinations (e.g., co-amoxiclav, piperacillin-tazobactam). To date there is a paucity of available data on antimicrobial resistance trends of anaerobic bacteria in Ireland, and our study aims to determine such patterns among isolates processed at our institution over the last ten years.

METHODS

Significant anaerobic bacteria isolated from clinical specimens processed at our laboratory from January 2010 to January 2020 inclusive were reviewed. Bacteria were identified using MALDI-TOF, with E-tests used for antimicrobial susceptibility testing. Data was processed through WHONET.

RESULTS

A total of 2098 clinically significant anaerobic bacterial isolates from blood cultures (31%), theatre/intraoperative specimens (30%), aspirates and drain fluid (22%) and wound swabs (17%) were reviewed during the study period; with the majority of isolates being Bacteroides spp (32.79%, n = 688) and Clostridium spp (18.68%, n = 392). With isolates demonstrating well-recognised or inherent resistances excluded, overall resistance to tested antimicrobials was 6.40% to penicillin, 1.71% to metronidazole, 1.43% to co-amoxiclav, 13.63% to clindamycin, 0.43% to piperacillin-tazobactam and 0% to meropenem.

CONCLUSION

Metronidazole and beta-lactam/beta-lactamase inhibitor combinations remain highly efficacious against the majority of anaerobic isolates reviewed, and can safely be used as empiric therapy in suspected anaerobic infections. However, periodic surveillance of resistance trends remains important.

1080 An Audit on Compliance with Recommended Duration of Surgical Antimicrobial Prophylaxis in St. Vincent’s University Hospital, Dublin, Ireland

Aim

Surgical site infection (SSI) is a common healthcare-associated infection, and a frequent cause of post-operative morbidity. SSI comprises any infection of the operative incision, cavity or involved organ, that occurs within the 30-day post-operative period. Antimicrobial prophylaxis is critical in reducing SSIs. Our aim was to assess adherence to the recommended surgical antimicrobial prophylaxis guidelines in St. Vincent’s University Hospital (SVUH), as part of the hospital antimicrobial stewardship programme. Compliance of surgical services was measured against the recommended regimens described in the SVUH Antimicrobial Guidelines.

Method

Data on duration and choice of prophylaxis were prospectively gathered on inpatients undergoing elective surgery during a three-week period between August-September 2020. Patients undergoing transplant procedures, inpatients in the intensive care unit, and patients who moved off-site postoperatively were excluded.

Results

Eighty-one patients were included. Sixty-four (79%) were compliant with prophylaxis duration, while seventeen (21%) were not. Reasons for extended prophylaxis included three (18%) cases where there were intra-operative complications and five (29%) cases of routine prescribing of an additional 24-hour coverage. Nine (53%) did not document the reason for extended cover.

Conclusions

Compliance with recommended duration of prophylaxis improved in comparison to prior audits. Among patients receiving extended prophylaxis, documentation of the indication was poor. Patients with evidence of post-operative infection may be better served with targeted antimicrobial therapy rather than extended prophylaxis. One reason for extended prophylaxis may be due to difficulty accessing guidelines on recommended prophylaxis duration, hence a targeted smartphone application was introduced to improve accessibility.

Cytokine responses to Staphylococcus aureus bloodstream infection differ between patient cohorts that have different clinical courses of infection

Background

The clinical course of Staphylococcus aureus bloodstream infection is unpredictable and bacterial virulence, host immune response and patient characteristics are among the factors that contribute to the clinical course of infection. To investigate the relationship between cytokine response and clinical outcome, circulating cytokine levels were investigated in response to S. aureus bloodstream infection in patients with different clinical courses of infection.

Methods

A prospective study was carried out in 61 patients with S. aureus bloodstream infection and circulating levels of IL-6, GRO-γ, RANTES and leptin were assessed over the course of the infection. Levels were compared in patients with complicated courses of infection (e.g. infective endocarditis) versus uncomplicated courses of S. aureus bloodstream infection and methicillin-resistant S. aureus Vs methicillin-susceptible S. aureus infection.

Results

Significantly lower leptin levels (p < 0.05) and significantly higher IL-6 levels (p < 0.05) were detected at laboratory diagnosis in patients with complicated compared to uncomplicated S. aureus bloodstream infection. Significantly higher levels of GRO-γ were associated with MRSA infection compared to MSSA infection.

Conclusions

IL-6 may be an early inflammatory marker of complicated S. aureus bloodstream infection. Leptin may be protective against the development of a complicated S. aureus bloodstream infection.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0580-6) contains supplementary material, which is available to authorized users.

Effectiveness and cost-effectiveness of admissions to women's crisis houses compared with traditional psychiatric wards: pilot patient-preference randomised controlled trial

BACKGROUND

Women's crisis houses have been developed in the UK as a less stigmatising and less institutional alternative to traditional psychiatric wards.

AIMS

To examine the effectiveness and cost-effectiveness of women's crisis houses by first examining the feasibility of a pilot patient-preference randomised controlled trial (PP-RCT) design (ISRCTN20804014).

METHOD

We used a PP-RCT study design to investigate women presenting in crisis needing informal admission. The four study arms were the patient preference arms of women's crisis house or hospital admission, and randomised arms of women's crisis house or hospital admission.

RESULTS

Forty-one women entered the randomised arms of the trial (crisis house n = 19, wards n = 22) and 61 entered the patient-preference arms (crisis house n = 37, ward n = 24). There was no significant difference in outcomes (symptoms, functioning, perceived coercion, stigma, unmet needs or quality of life) or costs for any of the groups (randomised or preference arms), but women who obtained their preferred intervention were more satisfied with treatment.

CONCLUSIONS

Although the sample sizes were too small to allow definite conclusions, the results suggest that when services are able to provide interventions preferred by patients, those patients are more likely to be satisfied with treatment. This pilot study provides some evidence that women's crisis houses are as effective as traditional psychiatric wards, and may be more cost-effective.

Presenting your structures: the CCP4mg molecular-graphics software

The CCP4 molecular-graphics program now uses the Qt framework to provide a modern look and feel. There are many new features including rendering for publication-quality images and sequence alignment.

CCP4mg is a molecular-graphics program that is designed to give rapid access to both straightforward and complex static and dynamic representations of macromolecular structures. It has recently been updated with a new interface that provides more sophisticated atom-selection options and a wizard to facilitate the generation of complex scenes. These scenes may contain a mixture of coordinate-derived and abstract graphical objects, including text objects, arbitrary vectors, geometric objects and imported images, which can enhance a picture and eliminate the need for subsequent editing. Scene descriptions can be saved to file and transferred to other molecules. Here, the substantially enhanced version 2 of the program, with a new underlying GUI toolkit, is described. A built-in rendering module produces publication-quality images.

Esotropia following posterior superior alveolar nerve block

Adequate use of local anesthetics is an important phase of modern dentistry. Regardless of the care used in administration of local anesthetics, unusual reactions can occur. A case is presented in which posterior superior alveolar administration of two percent Lidocaine 1/100,000 epinephrine resulted in medial rotation of the orbit (esotropia).

The concentration of prostaglandin E2 in human periradicular lesions

Prostaglandins (PG) have been implicated in the genesis of periapical lesions. Periapical specimens from patients with clinical signs and symptoms of chronic and acute apical periodontitis were obtained and immediately frozen in liquid nitrogen. Periradicular tissues from unerupted third molars were frozen and used as controls. The concentration of PGE2 was determined by radioimmunoassay. Low levels of PGE2 were found in the control tissues as compared with those detected in chronic and acute lesions. Significantly higher levels of PGE2 were found in acute lesions than those found in chronic lesions. The results show that acute lesions have higher concentrations of PGE2 than chronic lesions and confirm the role of prostaglandins in the pathogenesis of human periapical lesions.