Variovorax durovernensis sp. nov., a novel species isolated from an infected prosthetic aortic graft in a human.

A novel bacterial strain, GSTT-20T was isolated from an infected, prosthetic endovascular graft explanted from a shepherd in London, United Kingdom. This strain was an aerobic, catalase-positive, oxidase-negative, Gram-stain-negative, motile, curved rod. It grew on blood agar, chocolate agar and MacConkey agar incubated at 37 °C in an aerobic environment after 48 h, appearing as yellow, mucoid colonies. Analysis of the complete 16S rRNA gene sequence showed closest similarity to Variovorax paradoxus with 99.6 % identity and Variovorax boronicumulans with 99.5 % identity. Phylogenetic analysis of the 16S rRNA gene sequence and phylogenomic analysis of single nucleotide polymorphisms within 1530 core genes showed GSTT-20T forms a distinct lineage in the genus Variovorax of the family Comamonadaceae. In silico DNA-DNA hybridization assays against GSTT-20T were estimated at 32.1 % for V. boronicumulans and 31.9 % for V. paradoxus. Genome similarity based on average nucleotide identity was 87.50 % when comparing GSTT-20T to V. paradoxus. Based on these results, the strain represented a novel species for which the name Variovorax durovernensis sp. nov. was proposed. The type strain is GSTT-20T (NCTC 14621T=CECT 30390T).

Main altered characteristics in the meat of young cattle of different sexual conditions supplemented in tropical pasture.

The aim was to identify the predominant variables in the differentiation of meat quality of cattle submitted to surgical castration, immunocastration, or non-castration and finished in a tropical pasture. Thirty-nine crossbred cattle were used and distributed in three treatments: i) surgical castration; ii) immunocastration; and iii) non-castration, with an initial mean age of 14.06±0.72 months and a mean weight of 284.10±31.40 kg. We used the principal component analysis to differentiate the qualitative meat characteristics between the treatments. Based on that analysis, we found that the first three principal components explained 71.44% of the total variation in the meat quality data, which ensures that the variation found is associated with the effect of the treatments. The characteristics correlated with the first three principal components and responsible for the discrimination between sexual conditions were subcutaneous fat thickness, instrumental meat color, cooking loss and shear force. These characteristics were similar among castrated animals, regardless of the methods. Therefore, immunological castration preserves the attributes of the meat and prevents possible damage to the physical and mental integrity of the animals. Finally, principal component analysis is an important methodology in the objective investigation of beef meat attributes.

Ventilator-associated pneumonia in neonates: the role of point of care lung ultrasound.

No consensus exists regarding the definition of ventilator-associated pneumonia (VAP) in neonates and reliability of chest X-ray (CXR) is low. Lung ultrasound (LU) is a potential alternative diagnostic tool. The aim was to define characteristics of VAP in our patient population and propose a multiparameter score, incorporating LU, for VAP diagnosis. Between March 25, 2018, and May 25, 2019, infants with VAP were identified. Clinical, laboratory and microbiology data were collected. CXRs and LU scans were reviewed. A multiparameter VAP score, including LU, was calculated on Day 1 and Day 3 for infants with VAP and for a control group and compared with CXR. VAP incidence was 10.47 episodes/1000 ventilator days. LU and CXR were available for 31 episodes in 21 infants with VAP, and for six episodes in five patients without VAP. On Day 1, a VAP score of > 4, and on Day 3 a score of > 5 showed sensitivity of 0.94, and area under the curve of 0.91 and 0.97, respectively. AUC for clinical information only was 0.88 and for clinical and CXR 0.85.Conclusion: The multiparameter VAP score including LU could be useful in diagnosing VAP in neonates with underlying lung pathology. What is Known: • Ventilator associated pneumonia (VAP) is common in infants on the neonatal unit and is associated with increased use of antibiotics, prolonged ventilation and higher incidence of chronic lung disease. • Commonly used definitions of VAP are difficult to apply in neonates and interpretation of chest X-ray is challenging with poor inter-rater agreement in patients with underlying chronic lung disease. What is New: • The multiparameter VAP score combining clinical, microbiology and lung ultrasound (LU) data is predictive for VAP diagnosis in preterm infants with chronic lung disease. • LU findings of VAP in neonates showed high inter-rater agreement and included consolidated lung areas, dynamic bronchograms and pleural effusion.

Partum and postpartum characteristics on the postpartum rebreeding in beef cattle.

The objective was to evaluate the influence of calving and postpartum characteristics, measured in different genetic predominance, on the postpartum rebreeding. Were evaluated 437 partum from cows that received feeding management consisting of a forage base of the native field and the mating season consisted of 90 days. The measurements were used from the data base (age of cow, genetic predominance, body weight, body condition score and date of calving) of the cows in the partum and postpartum period. The variables were submitted to analysis of multiple variances, multiple regression, correlation and cluster. Already the groups formed by cluster analysis were submitted to analysis of variance and F test and the means, compared by Student's t-test, α=0.05 probability. The increase in the mean at 0.14 points in the body condition score at calving and the occurrence of calving 9 days earlier at the calving season gives the Charolais genetically predominant cows repeat calves. The Nellore genetic predominance when they calved with similar body condition score (2.32 points) and showed a negative body weight gain at weaning (-3.0 kg and -2.1 kg) showed different behaviors, where they did not repeat the offspring, when they calved and weaned with smaller body weight.

Management of Bartonella Prosthetic Valve Endocarditis without Cardiac Surgery.

Two cases of Bartonella prosthetic valve endocarditis were cured when treated for 2 weeks with gentamicin and 3 months with doxycycline. Clinical cure correlated with decreased Bartonella antibody titers. This report suggests a strategy to monitor, treat, and cure Bartonella prosthetic valve endocarditis.

Streptococcus oralis meningitis in pregnancy.

While pregnancy is a time of relative immunosuppression, infective endocarditis and bacterial meningitis remain rare. We present a case of a pregnant woman with Streptococcus oralis endocarditis and meningitis. This is the first reported case of Streptococcus oralis meningitis in a patient without predisposing risk factors. This case highlights the importance of collecting blood cultures in febrile illness during pregnancy and illustrates that effective management plans can be formulated without performing invasive diagnostic tests such as transesophageal echocardiography.

Non-tuberculous slow-growing mycobacterial pulmonary infections in non-HIV-infected patients in south London.

BACKGROUND: UK data on slow-growing non-tuberculous mycobacterial (NTM) pulmonary infections are sparse and there is little consensus on optimal treatment regimens. METHODS: This was a retrospective study of NTM pulmonary infections in a London teaching hospital. Inclusion criteria were culture of slow-growing mycobacteria between 2000 and 2007, age > 18 y, HIV-negative, and meeting American Thoracic Society criteria. RESULTS: Fifty-seven patients were included; 68% were males and the median age was 61 y. Predisposing factors were smoking (70%), alcohol abuse (28%), and chronic obstructive pulmonary disease (37%). Cavitation (56%) and infiltrates (42%) were common radiological findings. The predominant organism was Mycobacterium kansasii (70%). Ninety-three percent of patients with M. kansasii, 63% with Mycobacterium avium intracellulare, 60% with Mycobacterium malmoense, and 25% with Mycobacterium xenopi had clinical disease. Of the 57 patients, 37 were treated and had follow-up data available. Most patients received 3 drugs: rifampicin, ethambutol, and clarithromycin or ciprofloxacin for at least 9 months. Thirty percent experienced drug side effects. M. kansasii treatment had a 100% cure and 10% relapse rate, but 15% died. CONCLUSIONS: M. kansasii was the most common NTM and its isolation was predictive of clinical disease. Compared with other studies, treatment with 3 agents had a similar rate of cure and did not appear to reduce the relapse rate of disease, but did increase the risk of side effects.

Cardiac implantable electronic device-related endocarditis: a 12-year single-centre experience.

BACKGROUND: The incidence of cardiac implantable electrical device endocarditis (CIEDE) is increasing, but CIEDE remains a relatively poorly described infection. This case series describes our experience of the condition at a tertiary referral centre in London over a 12-y period. METHODS: We identified cases using an endocarditis database containing prospectively collected clinical and microbiological information. We also used data recorded in an electronic database of all cardiac implantable electrical device-related procedures. RESULTS: Thirty cases of CIEDE were treated at our institution during the study period. Presentation was most commonly with fever, and 93% of our patients had positive blood cultures. Vegetations were identified on echocardiography in only 70% of patients, although a transoesophageal echocardiogram (TOE) was performed in only half of the cases. Sixty-seven percent of our cases were defined as definite endocarditis according to the modified Duke criteria for infective endocarditis. Twenty-three patients underwent percutaneous explantation of their infected CIED (including 6 patients with vegetations greater than 10 mm in diameter), while 5 underwent surgical explantation. The overall in-hospital mortality was 17%. CONCLUSIONS: Our data confirm the life-threatening nature of CIEDE in a UK population. In addition, our experience suggests that percutaneous extraction of devices with large adherent vegetations may be safe, and that the selective use of TOE may not compromise outcomes. Lastly, we show that the modified Duke criteria do not perform very well with this condition, suggesting a need for specific, validated criteria for diagnosing CIEDE.

Melioidosis acquired by traveler to Nigeria.

We describe melioidosis associated with travel to Nigeria in a woman with diabetes, a major predisposing factor for this infection. With the prevalence of diabetes projected to increase dramatically in many developing countries, the global reach of melioidosis may expand.

Community-acquired Salmonella bacteraemia in patients with sickle-cell disease 1969-2008: a single centre study.

We document the aetiology of community-acquired bacteraemia in sickle-cell disease (SCD) patients and present clinical aspects of 11 cases of Salmonella bacteraemia. Prospective computerized records of all significant bacteraemic episodes presenting to our institution from 1969 to 2008 were analysed. Additional clinical information was drawn from hospital medical records. Six thousand three hundred and sixty-nine community-acquired bacteraemic episodes were documented, with 66 occurring in SCD patients. Salmonella species were the third most frequently isolated organism in SCD patients; 18% of bacteraemias in SCD patients were caused by Salmonella species vs 3% in non-SCD patients (p < 0.0001). Moreover, the proportion of community-acquired Salmonella bacteraemic episodes caused by non-Typhi species was significantly higher in SCD compared to other patients (p = 0.0015). Focal infection was identified in 7 of the 11 cases of Salmonella bacteraemia in SCD patients, with bone and joint accounting for 6 of these. Infection may have been acquired during travel to the tropics in 4 patients. Our study supports the view that SCD patients are particularly susceptible to Salmonella infection. These infections frequently require multiple surgical interventions and prolonged hospital stays. SCD patients should be advised to pay particular attention to food hygiene while travelling to the tropics.

Infective endocarditis: A contemporary update.

Infective endocarditis (IE) remains a rare condition but one with high associated morbidity and mortality. With an ageing population and increasing use of implantable cardiac devices and heart valves, the epidemiology of IE has changed. Early clinical suspicion and a rapid diagnosis are essential to enable the correct treatment pathways to be accessed and to reduce complication and mortality rates. In the current review, we detail the latest guidelines for the evaluation and management of patients with endocarditis and its prevention.

Mutations in the Plasmodium falciparum cytochrome b gene are associated with delayed parasite recrudescence in malaria patients treated with atovaquone-proguanil.

BACKGROUND: Fixed-dose combination antimalarial drugs have played an increasingly important role in the treatment and chemoprophylaxis of falciparum malaria since the worldwide failure of monotherapy with chloroquine. Atovaquone-proguanil is one such combination drug used both for prophylaxis in travellers, and for treatment of acute malaria cases in European hospitals and clinics. METHODS: A series of eight atovaquone-proguanil treatment failures and two prophylaxis breakthroughs from four UK hospitals from 2004-2008 were analysed for evidence of mutations in the pfcyt-b gene, previously found to be associated with failure of the atovaquone component. RESULTS: Parasites carrying pfcyt-b mutations were found in five falciparum malaria patients with recrudescent parasitaemia occurring weeks after apparently successful treatment of a primary infection with atovaquone-proguanil. Four of these cases carried parasites with the Tyr268Cys mutation in pfcyt-b, previously reported in two French patients with malaria. In contrast, mutations in pfcyt-b were not found in three patients treated with atovaquone-proguanil who exhibited delayed clearance of the primary infection, nor in two returning travellers with malaria who had used the combination for prophylaxis. Using current and previously published data, mean time to recrudescence of parasites carrying pfcytb codon 268 mutations was estimated as 28.0 days after treatment (95% C.I. 23.0 - 33.0 days), whereas treatment failures without codon 268 mutations received rescue treatment an average of 4.71 days after initial AP treatment (95% C.I. 1.76 - 7.67 days). CONCLUSION: Genetically-determined parasite resistance to atovaquone is associated with delayed recrudescence of resistant parasites three weeks or more after initial clearance of parasitaemia by atovaquone/proguanil therapy. The 268-Cys allele of pfcyt-b may have been overlooked in previous studies of atovaquone-proguanil treatment failure as it is not detected by current RFLP methods.

Campylobacter bacteremia in London: A 44-year single-center study.

PURPOSE: Campylobacter species are a well-recognized but rare cause of bloodstream infection. METHODS: Here we reviewed 41 cases of Campylobacter bloodstream infection occurring at a single center in London over 44years, comprising 0.2% of all recorded episodes during this time period. RESULTS: Patients had a mean age of 46years and, contrasting with previous reports, nearly 50% of our patients did not have significant comorbidities. Ciprofloxacin resistance increased over the study period with 35% of isolates overall being resistant compared with only 3% exhibiting macrolide resistance. Despite a minority of patients receiving appropriate empirical antibiotic therapy, overall mortality was only 7%. CONCLUSION: Campylobacter bacteremia remains a rare but significant cause of morbidity with a low associated mortality. Underlying immunosuppressive conditions are common but by no means universal. In our setting, macrolides would be favored as empirical agents to treat suspected Campylobacter enteritis, including cases with associated bacteremia.

Identification of the 'Streptococcus anginosus group' by matrix-assisted laser desorption ionization--time-of-flight mass spectrometry.

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) provides rapid, accurate and cost-effective identification of a range of bacteria and is rapidly changing the face of routine diagnostic microbiology. However, certain groups of bacteria, for example streptococci (in particular viridans or non-haemolytic streptococci), are less reliably identified by this method. We studied the performance of MALDI-TOF MS for identification of the 'Streptococcus anginosus group' (SAG) to species level. In total, 116 stored bacteraemia isolates identified by conventional methods as belonging to the SAG were analysed by MALDI-TOF MS. Partial 16S rRNA gene sequencing, supplemented with sialidase activity testing, was performed on all isolates to provide 'gold standard' identification against which to compare MALDI-TOF MS performance. Overall, 100 % of isolates were correctly identified to the genus level and 93.1 % to the species level by MALDI-TOF MS. However, only 77.6 % were correctly identified to the genus level and 59.5 % to the species level by a MALDI-TOF MS direct transfer method alone. Use of a rapid in situ extraction method significantly improved identification rates when compared with the direct transfer method (P<0.001). We recommend routine use of this method to reduce the number of time-consuming full extractions required for identification of this group of bacteria by MALDI-TOF MS in the routine diagnostic laboratory. Only 22 % (1/9) of Streptococcus intermedius isolates were reliably identified by MALDI-TOF MS to the species level, even after full extraction. MALDI-TOF MS reliably identifies S. anginosus and Streptococcus constellatus to the species level but does not reliably identify S. intermedius.

Identification and control of a gentamicin resistant, meticillin susceptible Staphylococcus aureus outbreak on a neonatal unit.

We describe the identification and control of an outbreak of gentamicin resistant, meticillin susceptible Staphylococcus aureus (GR-MSSA) on a 36-bed neonatal unit (NNU) in London. Control measures included admission and weekly screening for GR-MSSA, cohorting affected babies, environmental and staff screening, hydrogen peroxide vapour (HPV) for terminal disinfection of cohort rooms, and reinforcement of hand hygiene. Seventeen babies were affected by the outbreak strain over ten months; seven were infected and ten were asymptomatic carriers. The outbreak strain was gentamicin resistant and all isolates were indistinguishable by pulsed-field gel electrophoresis. The outbreak strains spread rapidly and were associated with a high rate of bacteraemia (35% of 17 affected patients had bacteraemia vs. 10% of 284 patients with MSSA prior to the outbreak, p=0.007). None of 113 staff members tested were colonised with GR-MSSA. GR-MSSA was recovered from 11.5% of 87 environmental surfaces in cohort rooms, 7.1% of 28 communal surfaces and 4.1% of 74 surfaces after conventional terminal disinfection. None of 64 surfaces sampled after HPV decontamination yielded GR-MSSA. Recovery of GR-MSSA from two high level sites suggested that the organism could have been transmitted via air. Occasional breakdown in hand hygiene compliance and contaminated environmental surfaces probably contributed to transmission.

Opportunistic infection and nuclear medicine.

Immunosuppression as a result of T- or B-cell dysfunction can be associated with a variety of illnesses as a result of the underlying disease or treatment causing the dysfunction, infection or, indeed, therapy. Immunodeficiency may be primary or secondary. Secondary causes of immune deficiency are more common and more frequently encountered during imaging. Immune deficiency can arise in patients with conditions such as leukemia and lymphoma; from infectious agents such as the human immunodeficiency virus (HIV); from the administration of drugs, including chemotherapy agents and steroids; and as a result of metabolic diseases such as renal failure and diabetes. A condition that often presents challenges in the interpretation of abnormal uptake within radionuclide imaging is the patient with HIV infection. This has been compounded in some ways by the introduction of highly active antiretroviral therapy and the advent of the immune reconstitution inflammatory syndrome. Imaging abnormalities are found in association with the underlying disease, eg, lymphoma, HIV which, on occasion, may be difficult to separate from an opportunistic infection. The primary value of radionuclide imaging and in particular (18)F-fluorodeoxyglucose-positron emission tomography is to rapidly establish the probable site of disease to direct biopsy or aspiration so that the underlying pathology can be confirmed. The value of single-photon emission computed tomography and positron emission tomography has been enhanced by the introduction of hybrid imaging so that the computed tomography element of the scan localizes the site of disease more accurately than imaging without the computed tomography. Interest in monitoring response to treatment of infection is increasing but care has to be taken as inflammatory uptake attributable to immune reconstitution inflammatory syndrome can be similar to a worsening of infective uptake and this can lead to misinterpretation of the effect of treatment. It is important for the imager to be aware of the effects of underlying treatments on functional imaging and therefore to have a full history of the disease and the drug treatments that the patient is taking.