Fatal aortic endocarditis associated with community-acquired Serratia marcescens infection in a dog

A 12 yr old Dalmatian was referred for evaluation of acute lethargy, fever, neurologic signs, and a recently ausculted heart murmur. Echocardiography in combination with blood cultures resulted in a diagnosis of nonhospital-acquired Serratia marcescens bacteremia and aortic valve endocarditis. Despite early diagnosis and aggressive therapy, the dog failed to respond to antimicrobials and died within 6 hr after admission. Necropsy findings included aortic valve endocarditis, septicemia, and diffuse thromboembolic disease. There was no history of pre-existing underlying disease or immunosuppressive therapy, and the dog had not been hospitalized before referral.

Tularemia in a common marmoset (Callithrix jacchus) diagnosed by 16S rRNA sequencing

We report a case of tularemia in a common marmoset (Callithrix jacchus) diagnosed by determination of the isolate's 16S ribosomal RNA (rRNA) gene sequence. Pathological examination of the animal revealed a multifocal acute necrotizing hepatitis, interstitial nephritis, splenitis, and lymphangitis of the mandibular, retropharyngeal, and cervical and mesenteric lymph nodes. Moreover, multiple foci of acute necrosis were found in the epithelium of the jejunum and the interstitium of the lung. Bacteriological investigations revealed a septicemia. The isolated infectious agent was uncommon, not routinely diagnosed in our laboratory and therefore difficult to identify by conventional tools in a reasonable time and effort. thus, we decided to perform a genetic analysis based on the 16S rRNA gene sequence. Thereby, an infection with Francisella tularensis, the causative agent of tularemia, was unambiguously diagnosed. This shows the great advantage 16S rRNA gene sequencing has as a general identification approach for unusual or rare isolates.

Factors Affecting Post-Capture Survivability of Lobster Homarus Americanus

Technological advances in gear and fishing practices have driven the global expansion of the American lobster live seafood market. These changes have had a positive effect on the lobster industry by increasing capture efficiency. However, it is unknown what effect these improved methods will have on the post-capture fitness and survival of lobsters. This project utilized a repeated measures design to compare the physiological changes that occur in lobsters over time as the result of differences in depth, hauling rate, and storage methodology. The results indicate that lobsters destined for long distance transport or temporary storage in pounds undergo physiological disturbance as part of the capture process. These changes are significant over time for total hemocyte counts, crustacean hyperglycemic hormone, L-lactate, ammonia, and glucose. Repeated measures multivariate analysis of variance (MANOVA) for glucose indicates a significant interaction between depth and storage methodology over time for non-survivors. A Gram-negative bacterium, Photobacterium indicum, was identified in pure culture from hemolymph samples of 100% of weak lobsters. Histopathology revealed the presence of Gram-negative bacteria throughout the tissues with evidence of antemortem edema and necrosis suggestive of septicemia. On the basis of these findings, we recommend to the lobster industry that if a reduction in depth and hauling rate is not economically feasible, fishermen should take particular care in handling lobsters and provide them with a recovery period in recirculating seawater prior to land transport. The ecological role of P. indicum is not fully defined at this time. However, it may be an emerging opportunistic pathogen of stressed lobsters. Judicious preemptive antibiotic therapy may be necessary to reduce mortality in susceptible lobsters destined for high-density holding facilities.

Phylogenetic position of Riemerella anatipestifer based on 16S rRNA gene sequences

Riemerella anatipestifer, the causative agent of septicemia anserum exsudativa (also called new duckling disease), belongs to the family Flavobacteriaceae of gram-negative bacteria. We determined the DNA sequences of the rrs genes encoding the 16S rRNAs of four R. anatipestifer strains by directly sequencing PCR-amplified rrs genes. A sequence similarity analysis confirmed the phylogenetic position of R. anatipestifer in the family Flavobacteriaceae in rRNA superfamily V and allowed fine mapping of R. anatipestifer on a separate rRNA branch comprising the most closely related species, Bergeyella zoohelcum, as well as Chryseobacterium balustinum, Chryseobacterium indologenes, and Chryseobacterium gleum. The sequences of the rrs genes of the four R. anatipestifer strains varied between 0.5 and 1.0%, but all of the strains occupied the same position on the phylogenetic tree. In general, differences in rrs genes were observed among R. anatipestifer strains, even within a given serotype, as shown by restriction fragment length polymorphism of PCR-amplified rrs genes.

Engineered liposomes sequester bacterial exotoxins and protect from severe invasive infections in mice

Gram-positive bacterial pathogens that secrete cytotoxic pore-forming toxins, such as Staphylococcus aureus and Streptococcus pneumoniae, cause a substantial burden of disease. Inspired by the principles that govern natural toxin-host interactions, we have engineered artificial liposomes that are tailored to effectively compete with host cells for toxin binding. Liposome-bound toxins are unable to lyse mammalian cells in vitro. We use these artificial liposomes as decoy targets to sequester bacterial toxins that are produced during active infection in vivo. Administration of artificial liposomes within 10 h after infection rescues mice from septicemia caused by S. aureus and S. pneumoniae, whereas untreated mice die within 24-33 h. Furthermore, liposomes protect mice against invasive pneumococcal pneumonia. Composed exclusively of naturally occurring lipids, tailored liposomes are not bactericidal and could be used therapeutically either alone or in conjunction with antibiotics to combat bacterial infections and to minimize toxin-induced tissue damage that occurs during bacterial clearance

Outbreak investigation identifies a single Listeria monocytogenes strain in sheep with different clinical manifestations, soil and water.

Listeria (L.) monocytogenes causes orally acquired infections and is of major importance in ruminants. Little is known about L. monocytogenes transmission between farm environment and ruminants. In order to determine potential sources of infection, we investigated the distribution of L. monocytogenes genetic subtypes in a sheep farm during a listeriosis outbreak by applying four subtyping methods (MALDI-TOF-MS, MLST, MLVA and PFGE). L. monocytogenes was isolated from a lamb with septicemia and from the brainstem of three sheep with encephalitis. Samples from the farm environment were screened for the presence of L. monocytogenes during the listeriosis outbreak, four weeks and eight months after. L. monocytogenes was found only in soil and water tank swabs during the outbreak. Four weeks later, following thorough cleaning of the barn, as well as eight months later, L. monocytogenes was absent in environmental samples. All environmental and clinical L. monocytogenes isolates were found to be the same strain. Our results show that the outbreak involving two different clinical syndromes was caused by a single L. monocytogenes strain and that soil and water tanks were potential infection sources during this outbreak. However, silage cannot be completely ruled out as the bales fed prior to the outbreak were not available for analysis. Faeces samples were negative, suggesting that sheep did not act as amplification hosts contributing to environmental contamination. In conclusion, farm management appears to be a crucial factor for the limitation of a listeriosis outbreak.

Interventional Laser-assisted Extraction of an Infected Trapped Ventriculoatrial Shunt Based on Techniques for Pacemaker Lead Explantation.

We present a case of successful interventional laser-assisted extraction of an endovascularly trapped long-term implanted ventriculoatrial shunt in a patient with shunt-associated septicemia. This approach is based on modified techniques for explantation of pacemaker leads and might be considered an additional option for extraction of otherwise nonremovable trapped endovascular catheters in experienced centers.

Significado de la Leucopenia en pacientes con bacteriemia

Objetivo: Evaluar parámetros clínicos, bacteriológicos y morbimortalidad de las bacteriemias en pacientes con leucopenia (<4.000 leucocitos/mm 3) y compararlas con bacteriemias con leucocitosis (>12.000/mm3). Material y métodos: Estudio protocolizado, descriptivo y observacional en pacientes con 2 o más hemocultivos positivos para el mismo germen hospitalizados en un servicio de clínica médica desde Marzo de 1989 a Agosto de 2007. Resultados: Se identificaron 728 bacteriemias, 94 (12,91%) con leucopenia (Grupo A) y 407 (55,90%) con leucocitosis (Grupo B). La edad media fue de 55,57 años (DS±16,93) en A y de 58,40 años (DS±17,34) en B. No hubo diferencias en la permanencia media: 19,59 días (DS±18,67) en A vs 21,21 (DS±19,53) en B ni en el sexo masculino (65,96 vs 57,25%)(pNS). La adquisición nosocomial (57,44 vs 40,29%) y el foco desconocido (25,53 vs 9,33%) y abdominal (17,14 vs 9,21%) fueron más frecuentes en A (p<0.01). La comorbilidad mayor (82,98 vs 41,24%), neoplasias (45,74 vs 12,84%) y la inmunosupresión (31,91 vs 6,17%) fueron significativas en A (p<0.01). La anemia (86,17 vs 62,40%) y la trombocitopenia (84,04 vs 25,06%) predominaron en A (p<0.01). Los Bacilos Gram Negativos predominaron en A (61,71 vs 37,83%)(p<0.01) [Klebsiella (17,02 vs 9,82%) y Pseudomonas (10,64 vs 1,47%) las más frecuentes (p<0.05)] y en B fue más frecuente S. aureus (31,69 vs 11,70%)(p<0.01). La mortalidad fue de 39,36% en A y 25,30% en B (p=0.006) y se asoció en el grupo A a mayor mortalidad en las primeras 24 horas (32,43 vs 16,50%), inmunosupresión (27,02 vs 7,76%), neumococcemias (52,94 vs 23,07%), sepsis (100 vs 88,35%) y trombocitopenia (75,67 vs 30,09%)(p<0,01).- Conclusiones: Las bacteriemias en pacientes leucopénicos comparadas con aquellas con leucocitosis se asociaron significativamente a adquisición nosocomial, foco desconocido y abdominal, presencia de comorbilidad mayor, neoplasias e inmunosupresión, a bacteriemias por Klebsiella y Pseudomonas y a significativa mayor mortalidad. Palabras claves: leucopenia, bacteriemias

Bacteriemias en Mayores de 65 años : resultados de un análisis comparativo

Objetivos: Evaluar parámetros clínicos, bacteriológicos y morbimortalidad en pacientes mayores de 65 años con bacteriemia (Grupo A) y compararlos con aquellas ocurridas en menores de 65 años (grupo B) hospitalizados en un servicio de clínica médica. Material y métodos: Estudio protocolizado, descriptivo y observacional, desde 1989-2006. Criterios de inclusión: dos o más hemocultivos positivos. Análisis estadístico con Epi Info 6.4 . Resultados: Se identificaron 668 bacteriemias: 258 (38,6%) en A y 410 (61,4%) en B. La edad media fue de 74,2 años (DS±7.01) y de 47,2 años (DS±13.7) respectivamente. No hubo diferencias en la permanencia media: 19,1 días (DS±17.07) en A y 19,9 (DS±18,1) en B, ni en el origen nosocomial (40,7 vs 44%). Los focos pulmonar (31 vs 21,2%)(p<0,008) y urinario (27 vs 18,8%)(p=0.017) fue más frecuentes en A. La fiebre >de 38 ºC fue menos frecuente en A (83,8 vs 90,9%)(p=0.0068), mientras que la hipotensión arterial (40,8 vs 32,2%)(p=0.03), oliguria (41,7 vs 30,9%)(p=0.005) y encefalopatía (54,5 vs 39,4%)(p=0.00014) fueron mas comunes en A. Los bacilos gram negativos predominaron en A (46 vs 37%)(p<0.01) con diferencias entre A.baumani (9,16 vs 4,6%) y E.coli (54,1 vs 42,7%)(p<0.05) y en B fueron más frecuentes por S.aureus MS (34.39 vs 24,63)(p=0.01). El shock séptico (33,9 vs 22,4%) y nuevas insuficiencias de órganos (31,1 vs 20,1%) prevalecieron en A (p<0,001). La mortalidad fue de 34,49% para A y de 23,41% para B (p=0,018) Conclusiones: Las bacteriemias en pacientes internados mayores de 65 años comparadas con las ocurridas en pacientes. de menor edad, se caracterizaron significativamente por tener predominio del foco pulmonar y urinario, de hipotensión arterial, oliguria y encefalopatía, de bacteriemia por BGN, principalmente A. baumanii y E. coli; mayor desarrollo de shock séptico, menor frecuencia de fiebre >38°C y de bacteriemia por MSS A, y significativa mayor mortalidad.

Anti-CD14 mAb treatment provides therapeutic benefit after in vivo exposure to endotoxin

The presence of endotoxin from Gram-negative bacteria signals the innate immune system to up-regulate bacterial clearance and/or killing mechanisms. Paradoxically, such responses also contribute to septic shock, a clinical problem occurring with high frequency in Gram-negative septicemia. CD14 is a receptor for endotoxin (lipopolysaccharide, LPS) and is thought to have an essential role in innate immune responses to infection and thereby in the development of septic shock. Using a novel rabbit model of endotoxic shock produced by multiple exposures to endotoxin, we show that anti-rabbit CD14 mAb, which blocks LPS-CD14 binding, protects against organ injury and death even when the antibody is administered after initial exposures to LPS. In contrast, anti-rabbit tumor necrosis factor mAb treatment fails to protect when administered after LPS injections. These results support the concept that anti-CD14 treatment provides a new therapeutic window for the prevention of pathophysiologic changes that result from cumulative exposures to LPS during septic shock in man.

Unique chromosomal regions associated with virulence of an avian pathogenic Escherichia coli strain.

The avian pathogenic Escherichia coli strain (chi)7122 (serotype O78:K80:H9) causes airsacculitis and colisepticemia in chickens. To identify genes associated with avian disease, a genomic subtraction technique was performed between strain (chi)7122 and the E. coli K-12 strain (chi)289. The DNA isolated using this method was found only in strain (chi)7122 and was used to identify cosmid clones carrying unique DNA from a library of (chi)7122 that were then used to map the position of unique DNA on the E. coli chromosome. A total of 12 unique regions were found, 5 of which correspond to previously identified positions for unique DNA sequence in E. coli strains. To assess the role each unique region plays in virulence, mutants of (chi)7122 were constructed in which a segment of unique DNA was replaced with E. coli K-12 DNA by cotransduction of linked transposon insertions in DNA flanking the unique sequence. The resulting replacement mutants were assessed for inability to colonize the air sac and cause septicemia in 2-week-old white Leghorn chickens. Two mutants were found to be avirulent when injected into the right caudal air sac of 2-week-old chickens. One avirulent mutant, designated (chi)7145, carries a replacement of the rfb locus at 44 min, generating a rough phenotype. The second mutant is designated (chi)7146, and carries a replacement at position 0.0 min on the genetic map. Both mutants could be complemented to partial virulence by cosmids carrying sequences unique to (chi)7122.

Caracterização genotípica de Arcobacter spp. isolados de carnes de aves comercializadas no Município de São Paulo - SP

Arcobacter spp. é um micro-organismo Gram negativo que provoca diarreia aquosa e sepse em seres humanos. A. butzleri, A. cryaerophilus e A. skirrowii são espécies patogênicas para humanos. O objetivo deste estudo foi detectar a presença de Arcobacter spp. na carne de aves comercializadas em açougues na cidade de São Paulo, verificando os genes de virulência e o perfil genotípico. Um total de 300 cortes de carne de frango foram submetidos ao cultivo e isolamento sob condições aeróbicas, a 30°C por 72 horas. Colônias suspeitas de Arcobacter spp. foram selecionadas para a detecção molecular pela reacção em cadeia da polimerase (PCR), a fim de determinar as espécies e os genes de virulência. Os resultados revelaram a presença de Arcobacter spp. em 18.3% (55/300) de amostras de carne de aves, sendo identificado como A. butzleri 63,6% (35/55) e A. cryaerophilus 36,3% (20/55). Os genes de virulência pesquisados demonstraram positividade de 100% (55/55) para o ciaB e mviN, seguidos de cj1349 98,1% (54/55), pldA 94,4% (52/55), cadF 72,7% (40/55), tlyA 92,7% (51/55), hecA 49% (27/55), irgA 47,2% (26/55) e hecB 34,5% (19/55). Estas cepas foram submetidas ao AFLP gerando dois dendogramas. Foram identificados 19 perfis genotípicos para A. butzleri e 17 para A. cryaerophilus. Os resultados desta pesquisa apontam a presença de A. butzleri e A. cryaerophilus na fase final da distribuição de carne de frangos nos açougues. A falta de inocuidade dos alimentos de origem animal, bem como a presença de estirpes virulentas representam riscos de Saúde Pública, com especial atenção para a possibilidade de contaminação cruzada gerados por alimentos crus e utensílios de cozinha

Infeções humanas por aeromonas

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

A treatise on the puerperal fever : wherein the nature and cause of that disease, so fatal to lying-in women, are represented in a new point of view illustrated by dissections; and a rational method of cure proposed, confirmed by experience /

Mode of access: Internet.

Beyträge zu den grundzügen der heilkunde für die gegenwärtige zeit. Nebst einer praktischen abhandlung vom kindbetterinnfieber.

Mode of access: Internet.