Bacteriology of abscesses of the central nervous system: a multicentre prospective study.

Pus from 46 patients with abscesses of the central nervous system (CNS) was examined for bacteria; bacteria were found in all patients. Streptococci were isolated from 36 patients and most isolates were Streptococcus milleri, Lancefield Group F, Ottens and Winkler type O III. Staphylococci were isolated from nine patients, organisms of the bacteroides group from 11, Proteus spp from seven, Klebsiella aerogenes from one, and Haemophilus aphrophilus from one. Pure cultures predominated over mixed cultures. Streptococci were isolated from abscesses of all types, and at all sites, but members of the Enterobacteriaceae and of the bacteroides group were isolated, in mixed cultures, principally from abscesses of the temporal lobe secondary to infection of the middle ear. Staphylococci predominated in abscesses that followed accidental or surgical trauma. Compared with fully sensitive control organisms, microbes infecting half the patients were resistant to penicillin. The prognosis of abscess of the CNS is grave, and the microbiological findings have important consequences for treatment. Prompt inoculation of specimens to culture plates and prompt incubation are mandatory if bacteria are to be cultured. Inhibitors of antimicrobial agents should be added to culture media if antibiotics have been administered. Provided that the site of the abscess and the antecedent history are ascertainable, the neurosurgeon should be able to start appropriate treatment while awaiting the results of culture.     

Abscess forming ability of streptococcus milleri group: synergistic effect with Fusobacterium nucleatum.

The abscess forming abilities of "Streptococcus milleri" strains (Streptococcus constellatus, Streptococcus anginiosus, and Streptococcus intermedius) isolated from dentoalveolar abscesses and the synergistic effect of Fusobacterium nucleatum co-inoculated with the isolates were examined on a mouse subcutaneous abscess model. Five days after inoculation, all S. milleri strains formed abscesses, which showed less pathological spread to surrounding connective tissues than those formed by Staphylococcus aureus 209P strain and were similar to those by F. nucleatum ATCC25586. When each S. milleri strain and F. nucleatum were co-inoculated, abscess sizes and each bacterial number recovered from abscesses increased in comparison to those treated by bacterial mono-inoculation of each S. milleri strain or F. nucleatum alone. The strongest synergistic effect was observed in the combination of S. constellatus and F. nucleatum. In a time course experiment with this combination, the recovery of S. constellatus subsequently decreased after the decrement of F. nucleatum, and it appeared that the association with F. nucleatum maintained the bacterial number of S. constellatus in the abscess. The cell-free supernatant of F. nucleatum had a tendency to increase the abscess size caused by S. constellatus in this model. When S. constellatus was cultured with F. nucleatum culture supernatant in vitro, growth enhancement in the early phase was observed. Furthermore, the phagocytic killing of S. constellatus by human polymorphonuclear leukocytes (PMNs) was significantly suppressed and the PMN membranes appeared to be injured by addition of the F. nucleatum culture supernatant. These results suggest that the pathogenicity of S. milleri strains in odontogenic infections may be enhanced by the co-existence of F. nucleatum.     

Septicaemia associated with an Aerococcus viridans infection in immunodeficient mice

This report describes a case series of septicaemia caused by infection with Aerococcus viridans in immunodeficient NOD/LtSz-Prkdc(scid) (NOD/SCID) mice. During a period of 3 weeks more than 40 animals died or became ill with clinical signs of ruffled coat, weight loss, laboured breeding, and distended abdomen. At necropsy it was found that the animals displayed symptoms of sepsis with widespread abscesses in the liver, heart, lungs or pyogenic peritonitis. A Gram-positive coccus was isolated in pure culture from the abscesses or peritoneum from affected animals. According to phenotypic and phylogenetic characterization, the isolate was identified as A. viridans. This is the first report of a spontaneous outbreak of septicaemia caused by A. viridans infection in immunodeficient laboratory mice and we conclude that A. viridans should be considered as a pathogen in immunodeficient mice.     

Bacteriologic studies of liver abscesses of Awassi sheep in Jordan

A total of 337 liver abscesses of Awassi sheep that were found in different slaughterhouses in Jordan were examined for their causal agents. Fifteen different bacterial species were isolated from 297 liver abscesses. No bacteria were isolated from the remaining 40 liver abscesses. Fusobacterium necrophorum biovar B were isolated from 195 (58%) abscesses. Arcanobacterium pyogenes, F. necrophorum biovar A, Escherichia coli and Clostridium perfringens were isolated from 41 (12%), 34 (10%), 30 (9%) and 17 (5%), respectively, liver abscesses. Our study suggested that F. necrophorum biovar B is the most prevalent bacterium incriminated for liver abscesses in Awassi sheep.     

Bacteriological study of otogenic cerebral abscesses: chemotherapeutic role of metronidazole.

In nine consecutive patients with otogenic cerebral abscesses a mixed growth of aerobic and obligate anaerobic bacteria was isolated from the pus in five patients, and in the remaining four obligate anaerobes were the sole isolates. The commonest obligate anaerobe isolated was Bacteroides fragilis, which was present in all but one patient. The patients were all treated with metronidazole for the anaerobic organisms and with appropriate chemotherapy against the aerobic organisms isolated. All the patients recovered and only one was left with a neurological deficit. As otogenic cerebral abscesses constitute a major proportion of all cerebral abscesses, the use of metronidazole against obligate anaerobic bacteria, which tend to dominate in such abscesses, should reduce the high mortality from this condition.     

Ribotyping to compare Fusobacterium necrophorum isolates from bovine liver abscesses, ruminal walls, and ruminal contents.

Restriction fragment length polymorphism analysis of rRNA genes was employed to genetically compare Fusobacterium necrophorum subsp. necrophorum and F. necrophorum subsp. funduliforme isolates from multiple abscesses of the same liver and isolates from liver abscesses, the ruminal wall, and ruminal contents from the same animal. Four livers with multiple abscesses and samples of ruminal contents, ruminal walls, and liver abscesses were collected from 11 cattle at slaughter. F. necrophorum was isolated from all liver abscesses, nine ruminal walls, and six ruminal content samples. Chromosomal DNA of the isolates was extracted and single or double digested with restriction endonucleases (EcoRI, EcoRV, SalI, and HaeIII); then restriction fragments were hybridized with a digoxigenin-labeled cDNA probe transcribed from a mixture of 16S and 23S rRNAs from Escherichia coli. EcoRI alone or in combination with EcoRV yielded the most discriminating ribopatterns for comparison. Within the subspecies multiple isolates from the same liver were indistinguishable based on the ribopattern obtained with EcoRI. The hybridization patterns of liver abscess isolates were concordant with those of the corresponding isolates from ruminal walls in eight of nine sets of samples. None of the six ruminal content isolates matched either the liver abscess isolates or the ruminal wall isolates. The genetic similarity between the isolates from liver abscesses and ruminal walls supports the hypothesis that F. necrophorum isolates of liver abscesses originate from the rumen.     

Detection of excretory <Emphasis Type="Italic">Entamoeba histolytica</Emphasis> DNA in the urine,and detection of <Emphasis Type="Italic">E. histolytica</Emphasis> DNA and lectin antigen in the liver abscess pus for the diagnosis of amoebic liver abscess

Background  

Amoebic liver abscess (ALA) and pyogenic liver abscesses (PLA) appear identical by ultrasound and other imaging techniques. Collection of blood or liver abscess pus for diagnosis of liver abscesses is an invasive procedure, and the procedure requires technical expertise and disposable syringes. Collection of urine is a noninvasive procedure. Therefore, there has been much interest shown towards the use of urine as an alternative clinical specimen for the diagnosis of some parasitic infections. Here, we report for the first time the detection of E. histolytica DNA excreted in the urine for diagnosis of the cases of ALA.     

儿童激素耐药型肾病综合征合并星形诺卡菌脑脓肿1例

本文报道1例激素耐药型肾病综合征儿童合并星形诺卡菌(Nocardia asteroides,N.asteroides)脑脓肿。患儿,男性,8岁,临床诊断为原发性肾病综合征(激素耐药型),病理诊断为局灶节段性肾小球硬化症(经典型)。肾穿后第4天患儿出现持续高热、抽搐,时有头痛,抗感染、抗凝治疗效果不佳。复查颅脑磁共振成像(magnetic resonance imaging,MRI)提示多发脑脓肿。头颅脓肿液经穿刺后培养显示为星形诺卡菌感染。予以多种抗生素联合糖皮质激素等治疗2个月,患儿体温正常,头痛缓解,脑脓肿范围明显缩小。因此,肾病综合征患儿在应用激素及免疫抑制剂治疗过程中如出现化脓性炎症,常规抗生素疗效差,应积极寻找病原,高度警惕诺卡菌病及其他机会性感染的可能。     

Successful antimicrobial therapy of hepatic,intra-abdominal and intrapelvic abscesses.

Antimicrobial therapy without surgical drainage or therapeutic aspiration was effective in the management of four patients with deep abscesses ranging in diameter from 1.3 to 10.0 cm. Two of the patients had multiple hepatic abscesses, one had hepatic, intra-abdominal and intrapelvic abscesses, and one had an intrapelvic abscess alone. Anaerobic bacteria were isolated from the blood or abscesses in all four patients, and an aerobic-anaerobic infection was present in one patient. The patients were treated with metronidazole, alone or in combination with other antibiotics, for 3 to 6 weeks. Therefore, in selected patients with deep abscesses, a therapeutic trial of antimicrobial agents instead of surgery may be justified.     

Metabolomic profiling of amoebic and pyogenic liver abscesses: an in vitro NMR study

Pus samples obtained from 109 patients with liver abscess were examined by NMR spectroscopy. To our knowledge this is the first report on metabolic profiling of liver abscesses. Fifty metabolites were identified by combination of one (1D) and two-dimensional (2D) NMR spectra. Metabolic derangements were evaluated for differentiation between amoebic (ALA) and pyogenic liver abscess (PLA). The NMR results indicate that aspartate, asparagine and galactose, integral components of lipoproteophophoglycans (LPG) of the cell wall of Entamoeba histolytica are metabolic biomarkers of ALA. On the other hand, acetate, propionate, butyrate, succinate and formate, the fermentation products the facultative anaerobes are significantly prevalent in PLA. The NMR based metabolic profile of ALA and PLA are evaluated taking polymerase chain reaction (PCR) and bacterial culture as gold standard method. However, when NMR results were compared with culture and PCR methods, a correct diagnosis of 94.11% in ALA (n?=?85) and 100% in PLA (n?=?10) cases were observed. NMR spectroscopy in conjunction with PCR and culture can expedite in differentiating ALA from PLA.     

Differentiation of Brain Abscesses from Glioblastomas and Metastatic Brain Tumors: Comparisons of Diagnostic Performance of Dynamic Susceptibility Contrast-Enhanced Perfusion MR Imaging before and after Mathematic Contrast Leakage Correction

Purpose

To compare the diagnostic performance of dynamic susceptibility contrast-enhanced perfusion MRI before and after mathematic contrast leakage correction in differentiating pyogenic brain abscesses from glioblastomas and/or metastatic brain tumors.

Materials and Methods

Cerebral blood volume (CBV), leakage-corrected CBV and leakage coefficient K₂ were measured in enhancing rims, perifocal edema and contralateral normal appearing white matter (NAWM) of 17 abscesses, 19 glioblastomas and 20 metastases, respectively. The CBV and corrected CBV were normalized by dividing the values in the enhancing rims or edema to those of contralateral NAWM. For each study group, a paired t test was used to compare the K₂ of the enhancing rims or edema with those of NAWM, as well as between CBV and corrected CBV of the enhancing rims or edema. ANOVA was used to compare CBV, corrected CBV and K₂ among three lesion types. The diagnostic performance of CBV and corrected CBV was assessed with receiver operating characteristic (ROC) curve analysis.

Results

The CBV and correction CBV of enhancing rim were 1.45±1.17 and 1.97±1.01 for abscesses, 3.85±2.19 and 4.39±2.33 for glioblastomas, and 2.39±0.90 and 2.97±0.78 for metastases, respectively. The CBV and corrected CBV in the enhancing rim of abscesses were significantly lower than those of glioblastomas and metastases (P = 0.001 and P = 0.007, respectively). In differentiating abscesses from glioblastomas and metastases, the AUC values of corrected CBV (0.822) were slightly higher than those of CBV (0.792).

Conclusions

Mathematic leakage correction slightly increases the diagnostic performance of CBV in differentiating pyogenic abscesses from necrotic glioblastomas and cystic metastases. Clinically, DSC perfusion MRI may not need mathematic leakage correction in differentiating abscesses from glioblastomas and/or metastases.     

Evaluation of antigen detection and polymerase chain reaction for diagnosis of amoebic liver abscess in patients on anti-amoebic treatment

ABSTRACT: BACKGROUND: Diagnosis of amoebic liver abscess (ALA) in patients on anti-amoebic drugs is difficult. There is scanty data on this issue using Entamoeba histolytica (E. histolytica) lectin antigen and polymerase chain reaction (PCR). We studied lectin antigen, PCR, and IgG antibody in liver abscess patients. Liver aspirate of 200 patients, of which 170 had anti-amoebic drug prior to drainage, was tested for E. histolytica lectin antigen by ELISA, PCR, bacterial culture, and serum IgG antibody by ELISA. Classification of abscesses was based on result of anti-amoebic IgG antibody and bacterial culture, E. histolytica PCR and bacterial culture, and E. histolytica lectin antigen and bacterial culture was evaluated. FINDINGS: Using anti-amoebic IgG antibody and bacterial culture, 136/200 (68.0%) were classified as ALA, 12/200 (6.0%) as pyogenic liver abscess (PLA), 29/200 (14.5%) as mixed infection, and 23/200 (11.5%) remained unclassified. Using amoebic PCR and bacterial culture 151/200 (75.5%) were classified as ALA, 25/200 (12.5%) as PLA, 16/200 (8.0%) as mixed infection, and 8/200 (4.0%) remained unclassified. With E. histolytica lectin antigen and bacterial culture, 22/200 (11.0%) patients were classified as ALA, 39/200 (19.5%) as PLA, 2/200 (1.0%) as mixed infection, and 137/200 (68.5%) remained unclassified. CONCLUSIONS: E. histolytica lectin antigen was not suitable for classification of patients who had prior anti-amoebic treatment. However, PCR may be used as alternative test to anti-amoebic antibody in diagnosis of ALA.     

Magnetic Resonance Spectroscopy Findings of Pyogenic, Tuberculous, and Cryptococcus Intracranial Abscesses

Proton magnetic resonance spectroscopy (MRS) complements conventional methods used to differentiate intracranial cystic lesions. We report MRS findings of three cases that were diagnosed as pyogenic, tuberculous, and Cryptococcus abscesses before instituting any medical or surgical therapy. The pyogenic brain abscess had typical specific spectral findings (i.e., the demonstration of amino acids). Lactate and lipid peaks were visible in the tuberculous abscess. Cryptococcus neoformans can appear differently in different brain regions, which may lead to different spectral findings.     

Characterization of clinical strains of MSSA,MRSA and MRSE isolated from skin and soft tissue infections and the antibacterial activity of ZnO nanoparticles

Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), is an important cause of pyogenic skin and soft tissue infections (SSTIs). MRSA is an important pathogen in the healthcare sector that has neither been eliminated from the hospital nor community environment. In humans, S. aureus causes superficial lesions in the skin and localized abscesses, pyogenic meningitis/encephalitis, osteomyelitis, septic arthritis, invasive endocarditis, pneumonia, urinary tract infections and septicemia. Investigations focused in the search of other alternatives for the treatment of MRSA infections are in progress. Among the range of compounds whose bactericidal activity is being investigated, ZnO nanoparticles (ZnO–NPs) appears most promising new unconventional antibacterial agent that could be helpful to confront this and other drug-resistant bacteria. The aim of present study is to investigate the antibacterial potential of ZnO–NPs against Staphylococcus species isolated from the pus and wounds swab from the patients with skin and soft tissue infections in a tertiary care hospital of north India. ZnO–NPs (≈19.82 nm) synthesized by sol–gel process were characterized using scanning electron microscopy, X-ray diffraction , and Atomic force microscopy. The antibacterial potential was assessed using time-dependent growth inhibition assay, well diffusion test, MIC and MBC test and colony forming units methods. ZnO–NPs inhibited bacterial growth of methicillin-sensitive S. aureus (MSSA), MRSA and methicillin-resistant S. epidermidis (MRSE) strains and were effective bactericidal agents that were not affected by drug-resistant mechanisms of MRSA and MRSE.     

Liver Abscesses in Intensively Fed Cattle

An attempt was made to determine the time of onset of liver abscesses in intensively fed calves. Determinations of seram proteins (total protein, albumin, globulin, albumin/ globulin ratio, agarose-gel electrophoretic separation and formol-gel test) and, in a part of the material, of serum-GOT and -GPT were made in serial samples taken once a month from 125 calves. Liver abscesses were found in 48 (38.4 %) when slaughtered at 6–7 months of age. Total protein and globulin increased, the albumin-globulin ratio decreased with increasing age. Calves with liver abscesses had a significantly (0.05 > P > 0.01) higher globulin concentration at the last sampling. At this sampling the material was of a limited size and the difference has to be interpreted with caution. No other significant differences were found. Nor were any rises observed in S-GOT and S-GPT referable to the formation of liver abscesses. Bacteriological studies were not made but, in analogy with observations on a similar animal material in another part of Sweden, the infectious agent in the liver abscesses was assumed to be Sph. necrophorus. The explanation of the almost absent changes in the serum proteins in calves with liver abscesses may be the low antigenicity of this bacterium. In conclusion it is stated that the present serial investigations of the serum protein pattern in young cattle provide no definite guidance for establishing the time of onset of liver abscesses.     

Spontaneous Nocardiosis With Brain Abscess Caused by Nocardia asteroides in a Cynomolgus Monkey

This paper deals with nocardiosis with brain abscess in a cynomolgus monkey imported from Indonesia. At necropsy, typical abscesses were found in the mandible, lung, kidney, heart, liver, and brain. Nocardia asteroides was isolated as the causative agent. The lesions in the kidney, heart, and brain were considered to be secondary metastases.     

Ultrasonography and Determination of Proteins and Enzymes in Blood for the Diagnosis of Liver Abscesses in Intensively Fed Beef Cattle

The concentrations of plasma proteins and the activities of liver enzymes were measured every 2 weeks from weaning to slaughter in 21 beef cattle, and their livers were examined ultrasonographically every 4 weeks. Eight of the 9 cases of single or multiple liver abscesses were detected by ultrasonography but some individual abscesses, particularly those in the left side of the liver, remained undetected. The time at which the abscesses were first detected ranged from 4 to 20 (mean 12.5) weeks. There were only slight variations in the blood constituents and they were of no significant value in the diagnosis of the liver abscesses.     

MyD88-dependent signals are essential for the host immune response in experimental brain abscess

Brain abscesses form in response to a parenchymal infection by pyogenic bacteria, with Staphylococcus aureus representing a common etiologic agent of human disease. Numerous receptors that participate in immune responses to bacteria, including the majority of TLRs, the IL-1R, and the IL-18R, use a common adaptor molecule, MyD88, for transducing activation signals leading to proinflammatory mediator expression and immune effector functions. To delineate the importance of MyD88-dependent signals in brain abscesses, we compared disease pathogenesis using MyD88 knockout (KO) and wild-type (WT) mice. Mortality rates were significantly higher in MyD88 KO mice, which correlated with a significant reduction in the expression of several proinflammatory mediators, including but not limited to IL-1beta, TNF-alpha, and MIP-2/CXCL2. These changes were associated with a significant reduction in neutrophil and macrophage recruitment into brain abscesses of MyD88 KO animals. In addition, microglia, macrophages, and neutrophils isolated from the brain abscesses of MyD88 KO mice produced significantly less TNF-alpha, IL-6, MIP-1alpha/CCL3, and IFN-gamma-induced protein 10/CXCL10 compared with WT cells. The lack of MyD88-dependent signals had a dramatic effect on the extent of tissue injury, with significantly larger brain abscesses typified by exaggerated edema and necrosis in MyD88 KO animals. Interestingly, despite these striking changes in MyD88 KO mice, bacterial burdens did not significantly differ between the two strains at the early time points examined. Collectively, these findings indicate that MyD88 plays an essential role in establishing a protective CNS host response during the early stages of brain abscess development, whereas MyD88-independent pathway(s) are responsible for pathogen containment.     

细菌性肝脓肿临床特点的回顾性分析

目的:总结细菌性肝脓肿(pyogenic liver abscesses,PLA)的临床特点、诊断及治疗经验,提高诊疗水平。方法:回顾性分析哈尔滨医科大学第二临床医学院2013年1月-2014年12月收治的75例PLA患者的临床资料。结果:75例患者的平均年龄57岁,最大78岁,最小34岁。其中,男45例,女30例,男:女为1.5:1。75例患者中表现为发热者69例(92.0%)、寒战28例(37.3%)、右上腹痛66例(88.0%),伴恶心呕吐者28例(37.3%),黄疸15例(20.0%),肝肿大8例(10.7%)。有糖尿病病史患者28例(37.3%)。胆系疾病(78.7%)是本组资料主要的易患因素,其中53例患有胆囊炎(70.7%)。外周血白细胞增高67例(89.3%),血红蛋白降低41例(54.7%),白蛋白降低46例(61.3%);75例患者转氨酶升高58例(77.3%)。肝右叶单发脓肿多见(75例患者中36例,占48%)。51例B超确诊,24例行B超+CT或CT检查。48例行穿刺液细菌培养及25例血培养,其中肺炎克雷伯氏菌为主要病原菌。平均住院天数为19天,多数患者经皮下肝脓肿穿刺或置管引流而好转,1例漏诊为肺炎,2例患者反复入院,1例因菌血症死亡。结论:PLA的临床表现多样,以发热最为常见;多为肝右叶单发,部分患者血红蛋白及血清白蛋白降低。糖尿病为PLA最常见基础疾病,胆系疾病是主要的易患因素。肺炎克雷伯杆菌是本组PLA患者的主要致病菌。     

Characterization of the bacterial microflora of the tympanic cavity of eastern box turtles with and without aural abscesses

Aerobic bacterial cultures of the tympanic cavity of the middle ear were performed in eight eastern box turtles (Terrapene carolina carolina) with aural abscesses and 15 eastern box turtles without aural abscesses (controls) that were admitted to The Wildlife Center of Virginia, Virginia, USA during 2003. Twenty-two bacterial isolates were identified from 17 turtles including 10 gram-negative and 12 gram-positive bacteria. Ten of 15 control animals had bacterial growth, resulting in identification of 13 bacteria, including six gram-negative and seven gram-positive agents. Seven of eight turtles with aural abscesses had bacterial growth, and 10 isolates were identified, including four gram-negative and six gram-positive organisms. The most frequently isolated bacteria from control animals were Micrococcus luteus (n = 3) and Pantoea agglomerans (n = 2). Morganella morganii (n = 2) was the only species isolated from the tympanic cavity of more than one turtle with aural abscesses. Staphylococcus epidermidis (n = 2) was the only species isolated from both groups. A trend toward greater bacterial growth in tympanic cavities of affected turtles compared with turtles without aural abscesses was noted. No single bacterial agent was responsible for aural abscesses in free-ranging eastern box turtles in this study, an observation consistent with the hypothesis that aerobic bacteria are not primary pathogens, but secondary opportunistic invaders of environmental origin.