A simplified blood culture sampling protocol for reducing contamination and costs: a randomized controlled trial

OBJECTIVES

Blood culture contamination carries risks for patients, such as unnecessary antimicrobial therapy and other additional hazards and costs. One method shown to be effective in reducing contamination is initial blood specimen diversion during collection. We hypothesized that initial blood specimen diversion without a designated device or procedure would suffice for reduction in blood culture contamination rate.

METHODS

From 1 September 2017 through to 6 September 2018, we conducted a randomized controlled trial to assess the effect of an initial-specimen diversion technique (ISDT) on the rate of blood-culture contamination by changing the order of sampling using regular vacuum specimen tubes instead of commercially available sterile diversion devices. We included adults from whom the treating physician planned to take blood cultures and additional blood chemistry tests. Additionally, we evaluated the potential economic benefits of an ISDT. This was a researcher-initiated trial, Clinicaltrials.gov NCT03088865.

RESULTS

In all, 756 patients were enrolled. This method, compared with the standard procedure in use at our medical centre, reduced contamination by 66% (95% CI 17%-86%), from 20/400 (5%) with the standard method to 6/356 (1.6%) with the ISDT, without compromising detection of true bloodstream infection and at no additional cost. Hospital-wide implementation of ISDT was associated with a 1.1% saving in hospitalization days.

CONCLUSIONS

We offer this novel approach as a simple, cost-effective measure to reduce risks to patient safety from contaminated blood cultures, without the need for using costly devices.

Seasonality of tuberculosis in Israel, 2001-2011

BACKGROUND

Several studies have suggested that the incidence of tuberculosis (TB) varies with the seasons.

OBJECTIVE

To determine the seasonality of TB in Israel and to explore possible associations with climatic variables.

METHODS

Laboratory-confirmed TB cases reported between 2001 and 2011 in individuals resident in Israel for at least 1 year before diagnosis were included in the study. Climatic variables included average temperature and average ultraviolet radiation. The mean serum 25-hydroxyvitamin D level of the population was also recorded.

RESULTS

Of all 2653 TB cases, incidence peaked during spring (n = 712) and reached its nadir during the fall (n = 577), with a case proportion amplitude (CPA) of 5.1% (P = 0.036). Individuals born in the Horn of Africa exhibited a CPA of 9.5% (P = 0.077). Mean population 25-hydroxyvitamin D level was significantly correlated with the seasonal pattern of the disease. Southern Israel had the highest global radiation and, counter-instinctively, the highest TB incidence.

CONCLUSIONS

TB exhibited a seasonal tendency in Israel, with the spring peak/fall nadir pattern found elsewhere. Vitamin D is suspected to be an explanatory variable for this seasonal phenomenon. The finding that the highest incidence is in the area receiving the highest global radiation suggests population-related vulnerability to vitamin D deficiency.

Invasive Aspergillosis in Neutropenic Patients with Hematological Disorders

Between 1983-1988, 72 patients with acute leukemia and 4 with aplastic anemia were treated in the Hematology Unit of The Chaim Sheba Medical Center. Ten patients with acute leukemia developed invasive pulmonary aspergillosis and 2 with aplastic anemia developed invasive aspergillosis of the nose and paranasal sinuses. These infections were diagnosed during a period of profound neutropenia while these patients were receiving broad spectrum antibiotics. The diagnosis of pulmonary aspergillosis was based on positive sputum cultures in 4 cases and on the appearance of typical clinical and radiologic features in six. In 2 culture-positive and in one culture-negative patient, the diagnosis was confirmed at autopsy. Thus, the diagnosis was definitive in 5 patients and probable in the remaining five patients. The 5 patients who achieved remission responded to antifungal treatment and recovered, while of the 5 who eventually died from the fungal infection, 4 did not achieve remission, and one died while in complete remission. In the 2 patients with aplastic anemia, aspergillosis was detected in cultures from necrotic nasal tissue. Both patients remained neutropenic, failed to respond to antifungal treatment and died within a short time after diagnosis. From this experience it appears that invasive aspergillosis in neutropenic patients is potentially curable if treated early by amphotericin B, provided that the neutrophil count recovers.

Epidemiology of infective endocarditis in a tertiary-center in Jerusalem: a 3-year prospective survey

BACKGROUND

Epidemiological features of infective endocarditis have changed during the last decades because of increases in the prevalence of health care exposure and of Staphylococcus aureus bloodstream infection. Consequently, the role of surgery is evolving. We aim to provide a contemporary profile of epidemiological, microbiological, and clinical features of infective endocarditis in a tertiary medical center, and identify predictors of mortality.

METHODS

A prospective observational cohort study of consecutive adult patients with definite endocarditis according to the modified Duke criteria. Data were collected from January 1, 2009 through October 31, 2011 following a predefined case report form designed by the ICE-PCS.

RESULTS

Among 70 endocarditis episodes, 25.7% involved prosthetic valves and 11.5% were device related. Forty-four percent of episodes were health-care associated. The predominant causative microorganism on native valve, prosthetic valve and device related endocarditis was Staphylococcus aureus (33.3%). Viridans group streptococci accounted for the majority of community-acquired endocarditis (36.1%). At least one complication occurred in 50% of the episodes. One third of the patients who had an indication for surgery were operated upon. Six month case fatality ratio was 40%. Sixty-five percent of patients with a contraindication to surgery died, compared with 9% and 28.5% who were treated surgically and medically, respectively. In multivariable analysis, age was a predictor of mortality.

CONCLUSION

Compared with other series, we observed more health-care associated endocarditis, and a higher mortality. Nearly half of all deaths were in patients who had a contraindication to surgery. Careful evaluation of contraindications to surgery is warranted.

Rapid identification of Enterobacter hormaechei and Enterobacter cloacae genetic cluster III

AIM

Enterobacter cloacae complex bacteria are of both clinical and environmental importance. Phenotypic methods are unable to distinguish between some of the species in this complex, which often renders their identification incomplete. The goal of this study was to develop molecular assays to identify Enterobacter hormaechei and Ent. cloacae genetic cluster III which are relatively frequently encountered in clinical material.

METHODS AND RESULTS

The molecular assays developed in this study are qPCR technology based and served to identify both Ent. hormaechei and Ent. cloacae genetic cluster III. qPCR results were compared to hsp60 sequence analysis. Most clinical isolates were assigned to Ent. hormaechei subsp. steigerwaltii and Ent. cloacae genetic cluster III. The latter was proportionately more frequently isolated from bloodstream infections than from other material (P < 0·05).

CONCLUSION

The qPCR assays detecting Ent. hormaechei and Ent. cloacae genetic cluster III demonstrated high sensitivity and specificity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The presented qPCR assays allow accurate and rapid identification of clinical isolates of the Ent. cloacae complex. The improved identifications obtained can specifically assist analysis of Ent. hormaechei and Ent. cloacae genetic cluster III in nosocomial outbreaks and can promote rapid environmental monitoring. An association was observed between Ent. cloacae cluster III and systemic infection that deserves further attention.

Déjà vu: Ralstonia mannitolilytica infection associated with a humidifying respiratory therapy device, Israel, June to July 2011

Following a bloodstream infection in June 2011 with Ralstonia mannitolilytica in a premature infant treated with a humidifying respiratory therapy device, an investigation was initiated at the Hadassah Medical Centres in Jerusalem. The device delivers a warmed and humidified mixture of air and oxygen to patients by nasal cannula. The investigation revealed colonisation with R. mannitolilytica of two of 15 patients and contamination of components of five of six devices deployed in the premature units of the Hadassah hospitals. Ten isolates from the investigation were highly related and indistinguishable from isolates described in an outbreak in 2005 in the United States (US). Measures successful in containing the US outbreak were not included in user instructions provided to our hospitals by the distributor of the device.

Déjà vu: Ralstonia mannitolilytica infection associated with a humidifying respiratory therapy device, Israel, June to July 2011

Following a bloodstream infection in June 2011 with Ralstonia mannitolilytica in a premature infant treated with a humidifying respiratory therapy device, an investigation was initiated at the Hadassah Medical Centres in Jerusalem. The device delivers a warmed and humidified mixture of air and oxygen to patients by nasal cannula. The investigation revealed colonisation with R. mannitolilytica of two of 15 patients and contamination of components of five of six devices deployed in the premature units of the Hadassah hospitals. Ten isolates from the investigation were highly related and indistinguishable from isolates described in an outbreak in 2005 in the United States (US). Measures successful in containing the US outbreak were not included in user instructions provided to our hospitals by the distributor of the device.

RheoDSC Analysis of Hardening of Semi-Crystalline Polymers during Quiescent Isothermal Crystallization

The crystallization of semi-crystalline polymers is often analyzed by rheometry and calorimetry. By rheometry the viscosity evolution during crystallization can be followed, whereas from a calorimetric measurement, the evolution of the degree of crystallinity can be calculated. The time evolution of these material properties is valuable input for polymer processing simulation software and in order to combine the data in a reliable manner, hardening curves are used as a characterization tool. Such a hardening curve correlates the relative increase of the viscosity resulting from crystallization, to the advancing degree of crystallinity. In this study, these are extracted from simultaneous measurements on one sample using a RheoDSC device. The RheoDSC technique allows for the direct combination of the rheological and calorimetric signal without the need of combining separate stand-alone measurement results. In this study, isothermal crystallization experiments are used to discuss the benefits of this approach. This will lead to the recommendation that measuring the hardening effect in steady shear measurements at very low shear rates in a direct combined RheoDSC setup is the most reliable method to compile unambiguously a material specific hardening curve for semi-crystalline polymers.

Antagonisms between Surfactants: The Case of Laundry Detergents

Interaction between surfactants forms micelles that typically lead to a reduction of the irritation potential of the mixture. The objective of this study is to illustrate that such antagonism between surfactants is applicable to actual cases of consumer products e.g. laundry detergent products. The Zein test is an in vitro assay measuring corn protein denaturation by solutions of surfactant(s) and often used to predict their acute irritation potential. The Zein test data for the surfactant mixtures from nine representative laundry detergents demonstrate that the protein denaturation by the mixtures is, in all cases, lower than the cumulative score of protein denaturation by the different surfactants tested separately. The data clearly indicate that antagonism occurs between the actual surfactants present in their exact proportions as found in the consumer laundry detergent products. These data support the view that the hazard classification of detergent products as (irritant) by the dangerous preparation directive should not be based on a simple cumulative score of the irritation properties of the individual components of the products.

Dynamics of childhood invasive meningococcal disease in Israel during a 22-year period (1989-2010)

AIM

To describe the dynamics in the incidence of childhood invasive meningococcal disease (IMD) in Israel during a 22-year period (1989-2010).

METHODS

A longitudinal prospective surveillance in all 27 medical centers with pediatric services in Israel. All cases of children <15 years old with positive blood/cerebrospinal fluid (CSF) culture for Neisseria meningitidis were reported. Demographic, clinical, and bacteriological data were recorded. Meningococcal vaccine was not routinely given to Israeli children during the study period.

RESULTS

The mean age ± standard deviation (SD) among the 743 cases was 40.7 ± 40.2 months. The mean yearly incidence/100,000 was 2.0 ± 0.8. Age-specific incidences were 8.7 ± 2.8, 2.9 ± 1.5, and 0.8 ± 0.5 for children <1, 1-4, and >4 years old, respectively. The overall incidence decreased significantly from 3.7 in 1989 to 1.5 in 2010. Meningitis constituted 69.2 % of all cases. The most common serogroups were: B (76.9 %), C (10.9 %), Y (8.0 %), and W(135) (2.9 %). 78.6 % of all serogroup B isolates were from children <5 years old (p < 0.01). Serogroup C was found mainly in children ≥5 years old (63.4 %). The case fatality rates (CFRs) for children <1, 1-4, >4 years old, and the total study population were 9.2, 12.3, 7.7, and 9.9 %, respectively. CFRs were higher for children without meningitis (14.9 %) compared to children with meningitis (7.9 %) (p < 0.01).

CONCLUSIONS

Overall, and for serogroups B and W135, childhood IMD rates decreased significantly in Israel during the study period, without routine vaccine usage. The most common serogroup in all age groups was B, which was most prevalent in children <5 years old. No change in the trend of the overall CFR was noted during the study period.

Destruction and formation of PCDD/Fs in a fluidised bed combustor co-incinerating automotive shredder residue with refuse derived fuel and wastewater treatment sludge

During an eight day trial automotive shredder residue (ASR) was added to the usual waste feed of a Fluidized Bed Combustor (FBC) for waste-to-energy conversion; the input waste mix consisted of 25% ASR, 25% refuse-derived fuel (RDF) and 50% wastewater treatment (WWT) sludge. All inputs and outputs were sampled and the concentration of the 17 PCDD/Fs with TEF-values was determined in order to obtain "PCDD/F fingerprints". The ASR contained approximately 9000 ng PCDD/Fs/kg(DW), six times more than the RDF and 10 times more than the WWT sludge. The fingerprint of ASR and RDF was dominated by HpCDD and OCDD, which accounted for 90% of the total PDDD/F content, whereas the WWT sludge contained relatively more HpCDFs and OCDF (together 70%). The flue gas cleaning residue (FGCR) and fly and boiler ash contained approximately 30,000 and 2500 ng PCDD/Fs/kg(DW), respectively. The fingerprints of these outputs were also dominated by HpCDFs and OCDF. The bottom ash contained only OCDD and OCDF, in total 8 ng PCDD/Fs/kg (DW). From the comparison of the bottom ash fingerprints with the fingerprints of the other output fractions and of the inputs, it could be concluded that the PCDD/Fs in the waste were destroyed and new PCDD/Fs were formed in the post combustion process by de novo synthesis. During the ASR-co-incineration, the PCDD/F congener concentrations in the fly and boiler ash, FGCR and flue gas were 1.25-10 times higher compared to the same output fractions generated during incineration of the usual waste mix (70% RDF and 30% WWT sludge). The concentration of the higher chlorinated PCDD/Fs increased most. As these congeners have the lowest TEF-factors, the total PCDD/F output, expressed in kg TEQ/year, of the FBC did not increase significantly when ASR was co-incinerated. Due to the relatively high copper levels in the ASR, the copper concentrations in the FBCs outputs increased. As copper catalysis the de novo syntheses, this could explain the increase in PCDD/F concentrations in these outputs.

Ongoing epidemic of Mycoplasma pneumoniae infection in Jerusalem, Israel, 2010 to 2012

A substantial epidemic of Mycoplasma pneumoniae infection was reported in late 2011 in some European countries. We report here an epidemic of M. pneumoniae infection that began in Jerusalem during 2010 and is still ongoing. This report complements current information on what might be a worldwide epidemic of M. pneumoniae infection that might require substantial coordinated international public health intervention.

Ongoing epidemic of Mycoplasma pneumoniae infection in Jerusalem, Israel, 2010 to 2012

A substantial epidemic of Mycoplasma pneumonia infection was reported in late 2011 in some European countries. We report here an epidemic of M. pneumonia infection that began in Jerusalem during 2010 and is still ongoing. This report complements current information on what might be a worldwide epidemic of M. pneumoniae infection that might require substantial coordinated international public health intervention.

Automotive shredder residue (ASR): reviewing its production from end-of-life vehicles (ELVs) and its recycling, energy or chemicals' valorisation

ASR is in Europe classified as hazardous waste. Both the stringent landfill legislation and the objectives/legislation related to ELV treatment of various countries, will limit current landfilling practice and impose an increased efficiency of the recovery and recycling of ELVs. The present paper situates ASR within the ELV context. Primary recovery techniques recycle up to 75% of the ELV components; the remaining 25% is called ASR. Characteristics of ASR and possible upgrading by secondary recovery techniques are reviewed. The latter techniques can produce a fuel- or fillergrade ASR, however with limitations as discussed. A further reduction of ASR to be disposed of calls upon (co-)incineration or the use of thermo-chemical processes, such as pyrolysis or gasification. The application in waste-to-energy plants, in cement kilns or in metallurgical processes is possible, with attention to the possible environmental impact: research into these impacts is discussed in detail. Pyrolysis and gasification are emerging technologies: although the sole use of ASR is debatable, its mixing with other waste streams is gradually being applied in commercial processes. The environmental impacts of the processes are acceptable, but more supporting data are needed and the advantage over (co-)incineration remains to be proven.

Assessment of the impact on human health of industrial emissions to air: does the result depend on the applied method?

The impact on human health of substances emitted to air by the Flemish industry was calculated with characterization factors (CFs) provided by the CML, Eco-indicator 99, EPS, EDIP and USEtox impact assessment methods. A comparison of the results pointed out that the choice of the CFs can greatly influence conclusions on the trend of the impact over time and on the relative contribution of the individual substances. If the impact on human health of organic substances and heavy metals was assessed separately, the differences between methods were less pronounced. In this case, the impacts on human health obtained by simply dividing the emitted masses of substances by the respective minimal risk concentrations or minimal risk doses, were comparable to those calculated with the CFs of the model-based methods.

Mass balance for POPs in a real scale fluidized bed combustor co-incinerating automotive shredder residue

The European directive 2000/53/EC implies a "reuse and recovery" rate for end-of-life vehicles (ELVs) of 95% to be reached by the year 2015. One of the options to increase the actual average European "reuse and recovery" rate of approximately 78% (EU 15, 2008) is incineration of automotive shredder residue (ASR) with energy-recovery. The mass balance and the congener fingerprints for PCDD/Fs, dioxin-like PCBs, PCBs and PAHs in a real scale fluidized bed combustor (FBC) incinerating 25% ASR with 25% refuse derived fuel (RDF) and 50% waste water treatment sludge (WWT sludge) were investigated. The PCDD/F, dioxin-like PCB, PCB and PAH concentrations in this input waste mix were more than hundred times higher than in the usual waste feed of the incinerator (30% RFD and 70% WWT sludge). In the outputs of the FBC, however, the concentrations of these POP groups were comparable or only slightly higher than in the outputs generated during the incineration of the usual waste feed. The considered POPs in the waste were destroyed efficiently and the formation of new POPs during cooling of the flue gas appeared to a large extent independent of the POP concentrations in the incinerated waste.

Mass balance for POPs in hazardous and municipal solid waste incinerators

The amount of different persistent organic pollutants (POPs) in the input of waste incinerators was compared to that in the output. Three cases were considered: a rotary kiln incinerating hazardous waste, a grate furnace incinerating municipal solid waste (MSW) and the same grate furnace co-incinerating plastics of waste of electrical and electronic equipment (WEEE) and automotive shredder residue (ASR) with MSW. The mass balance for PCBs in the rotary kiln indicates that these POPs are destroyed effectively during incineration. The grate furnace can be a sink or source of PCDD/Fs and PCBs depending on the concentrations in the incinerated waste. In order to compare the total amount of POPs in input and output, a methodology was developed whereby the amount of POPs was weighed according to minimal risk doses (MRDs) or cancer potency factors. For both incinerators the PCDD/Fs, PCBs and polyaromatic hydrocarbons (PAHs) are the main contributors to total weighed POP output. In MSW, the PCDD/Fs, PBDD/Fs and polybrominated diphenylethers (PBDEs) are the main contributors to the weighed POP input. The ratios of the weighed POP-input over -output clearly indicate that the rotary kiln incinerating hazardous waste is a weighed POP sink. The grate furnace incinerating MSW is a weighed POP sink or source depending on the POP-concentrations in the waste, but the difference between output and input is rather limited. When e.g. ASR and plastics of WEEE, containing high concentrations of PBDEs and PCBs, are co-incinerated in the grate furnace, it is clearly a weighed POP sink.

Elimination of symbiotic Aeromonas spp. from the intestinal tract of the medicinal leech, Hirudo medicinalis, using ciprofloxacin feeding

The use of the medicinal leech (Hirudo medicinalis) in promoting venous drainage in tissues whose vitality is threatened by venous congestion and obstruction, especially in plastic and reconstructive surgery, has been complicated by infections caused by Aeromonas spp. These are leech endosymbionts for which patients undergoing hirudotherapy frequently receive systemic chemoprophylaxis. In order to evaluate the possibility of rendering leeches safe for use on patients, H. medicinalis were fed artificially with a 2 g/L arginine solution (used as a phagostimulant) supplemented with ciprofloxacin (100 mg/L). Aeromonads were detected in 57 out of 80 control leeches (71.3%), but in none of the 56 leeches treated with ciprofloxacin (p <0.001). Treated leeches survived for up to 4 months. Tested weekly, 61% of these leeches took human blood for at least 4 weeks after treatment and all remained negative for aeromonads. All water samples in which leeches were kept before treatment were contaminated with Aeromonas spp.; none were detected in any of the NaCl/arginine solutions with which treated animals were fed. Molecular characterization of two phenotypically distinct isolates using gyrB sequencing showed that one clustered tightly with A. veronii and the other was closely related to A. media. Other environmental bacteria and fungi were isolated from 26.5% of treated leeches that had taken a blood meal 1-4 weeks after treatment. Ciprofloxacin reduced the number of leech-associated aeromonads to undetectable levels for extended periods. Most treated leeches were ready to take a blood meal after treatment, suggesting the possibility of using ciprofloxacin-treated leeches instead of chemoprophylaxis in patients undergoing hirudotherapy.

Culture-based methods for detection and identification of Streptococcus agalactiae in pregnant women--what are we missing?

We aimed to compare BD group B Streptococcus differential agar (GBSDA) with inoculation into LIM broth and subculture onto blood agar plates (LIM-BA) as a method for GBS screening in pregnant women. First, we compared the detection threshold and the ease of use of GBSDA with LIM-BA by inoculating known numbers of GBS mixed with approximately 10(5) cfu of other bacteria. Second, we tested the production of carotenoid pigment in 155 GBS blood culture isolates. Finally, we compared GBSDA, LIM broth with direct GBS antigen detection (LIM-AG) and LIM-BA as methods for GBS screening in pregnant women. GBS colonies were easily detected on GBSDA at a threshold of 20 cfu. In contrast, GBS was not detected in a mixed culture from LIM broth with initial inocula of up to 100 cfu. Orange pigment was produced in 146/155 GBS blood culture isolates. Pigment was not produced in eight non-hemolytic and two hemolytic strains. GBS was detected by GBSDA in 58 out of 297 parturient women (19.5%) but in only 50 (16.8%, P > 0.05) and 46 (15.4%, P = 0.079) women by LIM-BA and LIM-AG, respectively. GBSDA is a satisfactory medium for the rapid detection of most GBS isolates, but other methods may be needed if detection of all non-pigmented strains is required.

Invasive meningococcal disease in children in Jerusalem

Neisseria meningitidis is an important cause of childhood meningitis and septicaemia. Between 1999 and 2005, 133 invasive meningococcal disease (IMD) cases occurred in Jerusalem, 112 (84.2%) of them in children aged 0-14 years. The annual incidence rate in Jerusalem was higher than the national average (2.45+/-0.6 vs. 1.13+/-0.16/100 000 population, P=0.002). Most of the children (82.1%) were from low socio-economic Arab and Jewish ultra-orthodox communities; mortality was higher among Arab than Jewish children (1.3 vs. 0.22/100 000 person-years, P=0.004). A cluster of 10 children with severe meningococcal sepsis (three fatalities) emerged in the winter of 2003-2004. Compared to the other 102 cases in 1999-2005 both meningococcaemia (100% vs. 51%, P=0.003) and mortality (30% vs. 6.9%, P=0.014) rates were higher. Serogroup B comprised 77.6% of the bacterial isolates. Pulsed-field gel electrophoresis showed considerable variability among cluster isolates, but significant resemblance in Arab cases throughout 1999-2005. The increased susceptibility of specific sub-populations to IMD necessitates further evaluation.

Antibacterial properties of whole body extracts and haemolymph of Lucilia sericata maggots

OBJECTIVE

To partially characterise maggot-secreted antibacterial substances and determine their range of activity against different bacteria.

METHOD

Sterile and non-sterile maggots maintained in the laboratory and taken from chronic wounds of treated patients were used. Whole body extracts and haemolymph were fractionated and their range of activity against bacteria was tested using the zone of inhibition assay. The mode of action of bacterial destruction was examined by viable counts, influx of K+ and changes in the membrane potential by scanning electron microscope (SEM).

RESULTS

Extracts of sterile and non-sterile maggots showed an activity of 200 arbitrary units (AU)/ml and 400AU/ml respectively. Maggots removed from chronic wounds had an activity of 1200AU/ml. Injuring sterile maggots with a sterile needle doubled the antibacterial activity within 24 hours, while the antibacterial activity of haemolymph increased fourfold after injury with a sterile needle and sixteenfold with an infected needle. The fractions with a molecular weight of < 1kDa and 3-10kDa showed antibacterial activity against Gram-positive and Gram-negative bacteria including Pseudomonas aeruginosa, Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA) isolated from wounds. The fraction with a molecular weight of < 1kDa lysed over 90% of the bacteria within 15 minutes by causing an influx of K+ and changing the membrane potential of bacteria.

CONCLUSION

The nature of the antibacterial materials extracted from maggots not only indicates their ability to ingest the necrotic tissue on the wound, but also their potential significance in wound healing,

Evaluation of eight commercial tests for Mycoplasma pneumoniae antibodies in the absence of acute infection

Eight commercially available tests for Mycoplasma pneumoniae (Serodia-Myco II, Labsystems IgM and IgG EIA, IgM and IgG LISA tests, ImmunoWell IgG test and SeroMP IgM and IgG) were compared using 204 single sera from healthy individuals. IgM peaked in late childhood and then declined, while IgG rose progressively into adulthood. Inter-assay agreement was poor. Positivity in Serodia-Myco II and LISA IgG was associated with blood group or Coombs positivity, suggesting non-specific reactions. The study confirmed that single serum serology is unsuitable for the diagnosis of M. pneumoniae infection, and that commercially available tests need further improvement.

The effect of Perasafe® and sodium dichloroisocyanurate (NaDCC) against spores of Clostridium difficile and Bacillus atrophaeus on stainless steel and polyvinyl chloride surfaces

Clostridium difficile is an important cause of nosocomial diarrhoea. The aim of this study was to evaluate the potential for Perasafe, a recently introduced biocide, to contribute to control of C. difficile spores in the patient environment, in comparison with the chlorine-releasing agent sodium dichloroisocyanurate (NaDCC). These agents were evaluated against a water control, in a surface test on stainless steel and polyvinyl chloride (PVC) floor covering, materials commonly found in the hospital environment. The organisms studied were a toxigenic clinical isolate of C. difficile, and Bacillus atrophaeus (formerly B. subtilis var niger). The data indicate that in our in vitro system, Perasafe was significantly more active than NaDCC (1000 ppm available chlorine) against C. difficile spores dried on stainless steel surfaces, and against B. atrophaeus on PVC floor covering material, achieving mean log10 reduction factors in viable counts of 6 and 5.5, respectively, at 10 min exposures. Perasafe appeared to be less lethal in 10 min exposures to C. difficile spores fixed on PVC floor covering material. In general, 1000 ppm chlorine generated from NaDCC showed lower log10 reduction factors in viable counts at 10 min, ranging from 0.7 to 1.5, than Perasafe which ranged from 2.7 to 6.0. The potential efficacy of Perasafe in reducing the density of C. difficile spores in the patient environment in hospitals, nursing homes or other long-stay facilities should be evaluated in field studies.

Fungemia in a cancer patient caused by fluconazole-resistant Cryptococcus laurentii

We report the recent isolation of Cryptococcus laurentii from the blood of a patient given the diagnosis of ganglioneuroblastoma. The organism was identified using physiological and molecular characteristics, including morphology, carbohydrate and nitrate assimilation, urease activity, inability to form melanin on appropriate media, positive staining with diazonium blue B and sequence analysis of the D1/D2 domain of 26S ribosomal DNA. The isolate was resistant to fluconazole and 5-fluorocytosine using both the Etest and a broth microdilution assay. Repeated recovery of the organism from different blood cultures, and the patient's good response to treatment with amphotericin B support its etiological role. C. laurentii has rarely been implicated as a cause of clinically significant infections. The identity of reported isolates has not always been adequately documented, and some appear to have been isolated from lesions caused by Cryptococcus neoformans, emphasizing the true rarity of disease due to this fungus.

Cluster of neonatal infections in Jerusalem due to unusual biochemical variant of Enterobacter sakazakii

Reported here is a cluster of infections due to a nitrate-negative variant of Enterobacter sakazakii, which occurred among premature neonates at the Hadassah Hospital, Mount Scopus, Jerusalem, in December 1999-January 2000. Pulsed-field gel electrophoresis showed cluster isolates to be identical but unrelated to previous systemic isolates recovered in 1993 and 1998. The organism was not isolated from infant formula powder, but it was recovered from prepared formula and from a kitchen blender. Elimination of the environmental focus, a change to factory-prepared infant formula, and isolation of affected infants terminated the event. Faecal carriage of Enterobacter sakazakii was observed for up to 18 weeks, emphasising the potential for cross-infection.

Association between intensity of chlorhexidine use and micro-organisms of reduced susceptibility in a hospital environment

The potential for emergence of resistance to biocides has been a concern in recent years. This study tested whether an association exists between the intensity of chlorhexidine use and chlorhexidine susceptibility of micro-organisms isolated from patients in different clinical areas in an acute-care general hospital. Organisms frequently involved in nosocomial infections in the hospital were chosen for study over a six week period: Staphylococcus aureus (60 isolates), coagulase-negative staphylococci (48), Klebsiella pneumoniae (32), Pseudomonas aeruginosa (60), Acinetobacter baumannii (16) and Candida albicans (35). An index of chlorhexidine exposure for each clinical unit was derived for the year preceding organism collection. Chlorhexidine susceptibility was evaluated using agar incorporation minimum inhibitory concentrations (MICs) and disk diffusion. A statistically significant inverse correlation was shown between intensity of chlorhexidine use and the overall susceptibility of all study organisms taken together. There was no association when individual taxa were considered. These findings must be interpreted with caution considering that greater use of chlorhexidine is likely to occur in difficult clinical disciplines where antibiotic use, invasive procedures and other intensive care-related procedures, cross-infection and immunosuppression are all potential confounding factors. There was an excellent correlation between MICs and disk testing, suggesting that disk diffusion might be useful in studies involving more than one biocide.

Increasing incidence of gonorrhea in Israel associated with countrywide dissemination of a ciprofloxacin-resistant strain

The annual incidence of gonorrhea in Israel has sharply increased during the past 2 years. At the end of 1999, high-level ciprofloxacin-resistant strains of Neisseria gonorrhoeae (MIC90, > or =32 mcg/ml) also exhibiting decreased susceptibility to penicillin and tetracycline were isolated for the first time in southern Israel, as well as in other regions of the country. The incidence of male gonococcal urethritis in the south increased in a 1.5-year period from 3/100,000 to 12/100,000 ( P<0.05) in correlation with increased isolation of ciprofloxacin-resistant organisms. A marked increase in the incidence of gonorrhea was also encountered in Jerusalem, where ciprofloxacin resistance affected 54.5% of the isolates in 2000. Pulsed-field gel electrophoresis typing of gonococci from different areas of Israel indicated that all of the ciprofloxacin-resistant isolates belonged to identical or related strains. Since fluoroquinolone-resistant gonococci may emerge and disseminate extensively over a short period of time, continuous surveillance of antibiotic susceptibility among gonococcal isolates should be performed to guide empiric therapy.

Multidrug-resistant Trichosporon asahii infection of nongranulocytopenic patients in three intensive care units

Trichosporon asahii (Trichosporon beigelii) infections are rare but have been associated with a wide spectrum of clinical manifestations, ranging from superficial involvement in immunocompetent individuals to severe systemic disease in immunocompromised patients. We report on the recent recovery of T. asahii isolates with reduced susceptibility in vitro to amphotericin B (AMB), flucytosine, and azoles from six nongranulocytopenic patients who exhibited risk factors and who developed either superficial infections (four individuals) or invasive infections (two individuals) while in intensive care units. The latter two patients responded clinically and microbiologically to AMB treatment. All six isolates were closely related according to random amplified polymorphic DNA studies and showed 71% similarity by amplified fragment length polymorphism analysis, suggesting a common nosocomial origin. We also review the literature pertaining to T. asahii infections and discuss the salient characteristics of this fungus and recent taxonomic proposals for the genus.

Domain shuffling as a tool for investigation of protein function: substitution of the cysteine-rich region of Raf kinase and PKC eta for that of yeast Pkc1p

With the completion of the sequences of entire genomes, the need for functional characterisation of proteins and their domains is becoming acute. Conserved regions within proteins often share overlapping functions but despite this conservation may fulfil quite different tasks in different species. In this work, we investigated the cysteine-rich motif (C1 domain) of yeast protein kinase C (Pkc1p) as a model to establish a test system for domain function. C1 domains activate kinases through binding of either diacylglycerol and/or phosphatidylserine, as in many members of the protein kinase C (PKC) family, or by binding small GTPases, as in Raf kinase. In contrast to other members of the protein kinase C superfamily, Pkc1p of Saccharomyces cerevisiae is activated via binding of the small G-protein Rho1p to its C1 domain. We developed a system for domain shuffling to establish the function of C1 domains from human Raf kinase and rat PKC eta in yeast. Only the C1 domain from Raf kinase enabled the chimeric enzyme to bind Rho1p when substituted for the native yeast domain. Accordingly, a chimeric Pkc1p carrying the C1 from Raf kinase, but not that from PKC eta, was able to partially complement the phenotypes of a yeast pkc1 deletion mutant. We interpret these data as further evidence that interaction with a small GTPase is the main regulatory function of the C1 domain in yeast.

The yield of blood cultures in a department of emergency medicine

This study sought to determine the yield of blood cultures drawn in the department of emergency medicine. The results of 730 blood cultures taken from 718 patients were retrospectively analysed. The total percentage of positive cultures was 9.7%. Only 3.4% of the blood cultures were classified as true bacteraemia and the rest as contaminants. The commonest type of isolate was coagulase-negative staphylococci (49%), which were considered contaminants in all cases. Other contaminants represented 13.2% of all the positive blood cultures. The following bacteria comprised the group of true bacteraemia: Escherichia coli (12.6%), Streptococcus pneumoniae (9.8%), viridans streptococci (7%), Staphylococcus aureus (2.8%), Bacteroides fragilis (2.8%), Moraxella species (1.4%) and Flavobacterium species (1.4%). Blood cultures were positive in 3.6% of patients with pneumonia and in 10% of patients with urinary tract infections. In patients with fever of unclear source blood cultures were positive in 3.1% of children between 0-36 months of age and in 1.1% of patients older than 16 years. As a whole, patients with positive blood cultures were clinically sicker, a higher percentage of them required admission to the hospital and had higher temperatures or rapidly fatal disease, compared with the group of patients with negative blood cultures. In order to improve the yield of blood cultures in febrile patients, first, better a priori identification of those subjects at high risk for bacteraemia will reduce the number of unnecessary blood cultures and second, sterile venipuncture techniques should be improved in order to reduce the number of contaminants.

Enterobacter sakazakii infection in the newborn

Enterobacter sakazakii, a Gram-negative bacillus, previously known as "yellow pigmented Enterobacter cloacae", is a rare cause of neonatal infection. We describe the detailed clinical presentation of two cases in whom E. sakazakii was isolated in our neonatal service during the course of 1 mo. These include one case of sepsis and meningitis complicated by cerebral infarction, and one case of sepsis. In addition, three cases of intestinal colonization were identified. The source of the organism was thoroughly sought and was found to be a blender in the milk kitchen that was used for preparation of the reconstituted powdered milk formula.

CONCLUSION

Our paper adds clinical and laboratory information about the disease spectrum caused by this relatively rare organism and emphasizes the importance of a thorough search for the source of the infection.

Transient urethral obstruction predisposes to ascending pyelonephritis and tubulo-interstitial disease: studies in rats

Chronic tubulo-interstitial disease, an important cause of end-stage renal disease, often results from the combined effects of a disturbed urinary outflow tract and urinary tract infection. Acute unilateral ureteral obstruction in rats rapidly induces foci of medullary necrosis, confined to the region of the papilla and fornices. This injury may provide a nidus for bacterial invasion and may invoke reactive and regenerative changes, ultimately leading to chronic pyelonephritis and tubulo-interstitial nephropathy. To explore this possibility, adult rats underwent renal morphological evaluation 2-7 days following transient 24-h unilateral ureteral obstruction. In some experiments the bladder was inoculated with bacteria (10(8)-10(9) cfu/ml Escherichia coli in 0.5 ml) after release of ureteral obstruction, with subsequent cultures obtained from the pelvis of both kidneys and from the urinary bladder. Morphologic evaluation of perfusion-fixed kidneys, 2-7 days after the release of 24-h ureteral obstruction disclosed papillary necrosis, urothelial proliferation, marked inner-stripe interstitial expansion, and fibrosis and proximal tubular (S3) dilatation. The lateral (perihilar region) was predominantly affected, with lesions spreading from the fornices. There was some progression of interstitial fibrosis during the postobstructive time course or following more prolonged ureteral obstruction. By contrast, infection hardly contributed to the tubulointerstitial changes. In rats subjected to infection, cultures were positive in all 15 postobstructive kidneys, as opposed to five contralateral kidneys (P < 0.0001). Viable counts from the postobstructive kidney were also higher than those from the contralateral side (79,000 +/- 12,000 vs 2900 +/- 1600 cfu/ml, mean +/- SEM, P < 0.0001), and were comparable to those obtained from the bladder (77,000 +/- 13,000 cfu/ml). We conclude that transient ureteral obstruction predisposes to ascending pyelonephritis and to tubulointerstitial disease. This vulnerability may relate to altered urodynamics and medullary tissue destruction.