John Gerrard

Nematode symbiont for Photorhabdus asymbiotica

Photorhabdus asymbiotica is an emerging bacterial pathogen that causes locally invasive soft tissue and disseminated bacteremic infections in the United States and Australia. Although the source of infection was previously unknown, we report that the bacterium is found in a symbiotic association with an insect-pathogenic soil nematode of the genus Heterorhabditis.

Recurrent Bacteremia and Multifocal Lower Limb Cellulitis Due to Helicobacter-Like Organisms in a Patient with X-Linked Hypogammaglobulinemia

We describe a 27-year-old man with X-linked (Brutons) hypogammaglobulinemia who presented during a 10-month period with recurrent fevers and multifocal lower-limb cellulitis associated with bacteremia due to Helicobacter-like organisms (Flexispira rappini and Helicobacter canis). Susceptible individuals may acquire infection of this type as a result of exposure to young dogs.

Clinical diagnostic criteria for isolating patients admitted to hospital with suspected pandemic influenza.

Australian hospitals have now experienced the fi rst wave of pandemic H1N1 infl uenza during a southern hemisphere winter. Patients admitted to Australian hospitals with suspected pandemic infl uenza during this period were identifi ed by use of approved national clinical diagnostic criteria. However, the imprecise nature of clinical diagnosis limited the ability of hospitals to isolate infectious patients eff ectively before the laboratory confi rmation of infection (which typically takes a minimum of 48 h). Concern about our reliance on these criteria to isolate potentially infectious patients led us to analyse our early experience with pandemic infl uenza at the two teaching hospitals in the Gold Coast region of Queensland. We collected nasopharyngeal and throat specimens and reviewed clinical and laboratory data on all 346 patients admitted to the hospitals with acute respiratory disease during the period from May 24 to Aug 16, 2009. Pandemic H1N1 infl uenza virus RNA was detected in specimens collected from 106 of 346 patients (31%). On the basis of our experience, we compared the performance of Australian clinical diagnostic criteria with those of WHO, the US Centers for Disease Control and Prevention (CDC), and the UK Health Protection Agency (HPA; table). We make the following observations: (1) Criteria that rely on documented fever (eg, those of WHO and CDC) sacrifi ce sensitivity for specifi city. In our recent experience, 41 of 106 admitted patients (39%) with laboratory-confi rmed pandemic infl uenza did not have any tempera ture recorded above 37·8°C at any stage during their admission. Such criteria are simply not sensitive enough to support good hospital infection control practice. (2) Criteria that include a “history” of fever and respiratory symptoms rather than a documented fever (eg, those of the HPA and the Australian Government Department of Health and Ageing) are adequately sensitive to the diagnosis of pandemic infl uenza. However, the resulting lack of specifi city overwhelmed the ability of our hospitals to isolate suspected cases and resulted in cohorting of infected cases with wrongly suspected cases. (3) Age seems to be a useful criterion by which to discriminate pandemic infl uenza (H1N1) from other causes of acute respiratory disease necessitating hospital admission. Only four of 106 patients admitted with the infection were older than 65 years in our population. 80 (33%) of 240 patients admitted with acute respiratory disease not due to pandemic infl uenza were older than 65 years. Given the limitations of existing criteria, we have adopted a modifi ed approach with better sensitivity and specifi city for the purpose of isolating patients admitted to hospital during the pandemic: age less than 65 years and history suggestive of fever and cough or sore throat.

New plasmids and putative virulence factors from the draft genome of an Australian clinical isolate of Photorhabdus asymbiotica

Clinical isolates of Photorhabdus asymbiotica have been recovered from patients in both the United States of America and Australia, and the full sequence of P. asymbiotica ATCC43949 from the United States has been reported recently. In contrast to other bacteria in the genus that only infect insects, P. asymbiotica strains are able to infect both insects and humans. Using a combination of Solexa (Illumina) and 454 Life Sciences (Roche) sequence data in different assembly pipelines, we report on a draft genome sequence of a strain of P. asymbiotica recovered from a patient from Kingscliff, Australia. The best assembly yielded an N50 scaffold size of 288 627 base pairs (bp) with >88.6% of the predicted genome covered by scaffolds over 100 000 bp. One of the central differences found between this Australian isolate and the US isolate is the presence of an additional plasmid, pPAA3. This plasmid is similar to pCRY from Yersinia pestis, the causative agent of bubonic plague, and the presence of pPAA3 may account for the increased virulence of Australian isolates both against tissue culture cells and infected patients. The genome of the Kingscliff strain also contains several genomic differences from the US isolate, whose potential significance in virulence against both humans and insects is discussed.

An assessment of high touch object cleaning thoroughness using a fluorescent marker in two Australian hospitals

Abstract Objective We needed to better understand the usefulness of different methods of monitoring and achieving sustained improvement in cleaning. Common elements of successful international approaches include a covert nature, the use of a method to visually identify and highlight deficiencies in the cleaning of high touch objects (HTOs) and the provision of feedback and education before re-evaluation. The specific purpose of this study was to evaluate fluorescent marking, education and feedback for assessing and improving HTO cleaning in a typical Australian inpatient hospital setting. Methods A three-phase, prospective study was conducted in two acute care hospitals over 17 weeks. For each phase, in a set of 37 specific single-inpatient rooms, seven predefined HTOs were marked with a liquid isopropyl alcohol and optical brightener formulation targeting material solution containing a fluorescent marker (FM), known as DAZO ® , designed specifically for the purpose of evaluating surface cleaning. In each hospital we targeted rooms located in the four wards with the greatest de novo multidrug resistant organism burden. Forty-eight hours after applying the FM we used a black-light to visualise the marks presence or removal. In phase 1 only, HTOs were swabbed before marking. Also in the first phase only and immediately following the initial assessment, eachHTOwas cleaned, remarked and re-assessed at 48 h. Between phases 1 and 2, investigators provided results to environmental services (EVS) leadership and staff. Education was provided to EVS staff after phase 1 only. Results A total of 986 marks were evaluated. The cleaning scores for individual HTOs in phases 1–3 ranged from 9.4 to 77.8%, 10.8 to 93% and 13.5 to 67.7% respectively. In phase 3, three HTOs scored lower than in phase 1. The mean overall cleaning scores for phases 1–3 were 34%, 53% and 41% respectively. Conclusions The FM was useful to assess HTO cleaning thoroughness. It facilitated relevant feedback and education and motivated staff to strive for continual improvements in environmental cleaning. Without on-going education, preliminary improvements were unsustained. However, investigators better understood flaws in cleaning and policy/procedure conflicts.

Photorhabdus Species: Bioluminescent Bacteria as Human Pathogens?

We report two Australian patients with soft tissue infections due to Photorhabdus species. Recognized as important insect pathogens, Photorhabdus spp. are bioluminescent gram-negative bacilli. Bacteria belonging to the genus are emerging as a cause of both localized soft tissue and disseminated infections in humans in the United States and Australia. The source of infection in humans remains unknown.

Seasonal variation in health care-associated bloodstream infection: Increase in the incidence of gram-negative bacteremia in nonhospitalized patients during summer

OBJECTIVEnRecent research has suggested that episodes of gram-negative (GN) bloodstream infection (BSI) are more common in the population during summer months. Our objective was to determine if the same phenomenon could be observed in patients with health care-associated (HCA) BSI, and if so, whether a summer peak was less apparent in patients accommodated in a climate-controlled hospital environment.nnnMETHODSnData from episodes of HCA BSI spanning an 11-year period were analyzed. To test for seasonal variation in HCA BSI among hospitalized and nonhospitalized patients, and between GN and gram-positive organisms, the χ(2) goodness-of-fit test was used.nnnRESULTSnThere were 440 episodes of HCA GN BSI of which 259 (59%) occurred in inpatients and 181 (41%) occurred in noninpatients. A significant increase in the frequency of HCA GN BSI was observed in nonhospitalized patients during the summer months (P = .03) but not in climate-controlled hospitalized patients. The most common source of infection in these patents was an intravascular device (38%).nnnCONCLUSIONSnWe found an increased incidence of GN HCA BSI during summer that was not apparent in our inpatient cohort. The cause is unknown. It might be prudent to advise patients at risk of BSI (eg, those receiving intravascular infusions) to minimize exposure to high environmental temperature and to educate on possible behavioral factors that may increase risk.

Predicting influenza A and 2009 H1N1 influenza in patients admitted to hospital with acute respiratory illness

Objective To create a clinical decision tool for suspected influenza A (including 2009 H1N1) to facilitate treatment and isolation decisions for patients admitted to hospital with an acute respiratory illness from the emergency department (ED) during a 2009 H1N1 pandemic. Methods Cross-sectional study conducted in two hospitals in Queensland, Australia. All patients admitted to hospital from the ED between 24 May and 16 August 2009 with an acute respiratory illness were included. All had nasal and throat swabs taken. Data were collected from clinical chart review regarding clinical symptoms, co-morbidities, examination findings, pathology and radiology results. Influenza A status was detected by reverse transcription–PCR assay. Univariate and multivariate regression analyses were performed to identify independent predictors of influenza A status. Results 346 consecutive patients were identified, of which 106 were positive for 2009 H1N1 influenza; an additional 11 patients were positive for other influenza A viruses. Independent clinical predictors (with points allocated using weighted scoring) for all types of influenza A in patients admitted with acute respiratory illness were: age 18–64u2005years (2 points); history of fever (2); cough (1); normal level of consciousness (2); C-reactive protein >5 and ≤100u2005mg/l (2) and normal leucocyte count (1). A clinical score of 5 (presence of two or three predictors) gave a sensitivity of 93% (95% CI 87% to 96%), specificity of 36% (95% CI 30% to 42%), resulting in a negative-predictive value of 91% (95% CI 83% to 95%). Conclusion A clinical prediction tool was developed that may be able to assist in making appropriate isolation decisions during future 2009 H1N1 outbreaks.

Outbreak of health care-associated Burkholderia cenocepacia bacteremia and infection attributed to contaminated sterile gel used for central line insertion under ultrasound guidance and other procedures

Background: We report an outbreak of Burkholderia cenocepacia bacteremia and infection in 11 patients predominately in intensive care units caused by contaminated ultrasound gel used in central line insertion and sterile procedures within 4 hospitals across Australia. Methods: Burkholderia cenocepacia was first identified in the blood culture of a patient from the intensive care unit at the Gold Coast University Hospital on March 26, 2017, with 3 subsequent cases identified by April 7, 2017. The outbreak response team commenced investigative measures. Results: The outbreak investigation identified the point source as contaminated gel packaged in sachets for use within the sterile ultrasound probe cover. In total, 11 patient isolates of B cenocepacia with the same multilocus sequence type were identified within 4 hospitals across Australia. This typing was the same as identified in the contaminated gel isolate with single nucleotide polymorphism‐based typing, demonstrating that all linked isolates clustered together. Conclusion: Arresting the national point‐source outbreak within multiple jurisdictions was critically reliant on a rapid, integrated, and coordinated response and the use of informal professional networks to first identify it. All institutions where the product is used should look back at Burkholderia sp blood culture isolates for speciation to ensure this outbreak is no larger than currently recognized given likely global distribution.

Characterising a Ralstonia outbreak with a novel source

There are enormous challenges facing infection prevention and control in the 21st century. Countries across the world are confronted by ageing populations, restricted healthcare resources, demands for modern medicine and increasing antimicrobial resistance. Problem pathogens in the community are set to invade hospitals and those generated in hospitals are returned to the community. Continued consumption of antimicrobial agents is promoting and consolidating resistance to nearly all classes of drugs. Novel, known and resistant pathogens arising in one locality rapidly spread across the ‘global village’ courtesy of migration, conflict and international travel. We are facing unprecedented threats to the management of infection all over the world. This presentation will summarise the escalating challenges for infection control along with mention of current and future strategies for dealing with these. Despite the lack of evidence underpinning microbial transmission, basic hygiene practices remain the basis for protecting our patients. The science of infection prevention and control is set to become a key component in healthcare delivery. As we prepare for a world without antibiotics, research, education and policies on screening, isolation, cleaning and infection control have never been more important. Creative thinking, initiative and courage will be required for future management of infection in hospitals and communities everywhere.