Seasonal Occurrence and Carbapenem Susceptibility of Bovine Acinetobacter baumannii in Germany.

Acinetobacter baumannii is one of the leading causes of nosocomial infections in humans. To investigate its prevalence, distribution of sequence types (STs), and antimicrobial resistance in cattle, we sampled 422 cattle, including 280 dairy cows, 59 beef cattle, and 83 calves over a 14-month period. Metadata, such as the previous use of antimicrobial agents and feeding, were collected to identify putative determining factors. Bacterial isolates were identified via MALDI-TOF/MS and PCR, antimicrobial susceptibility was evaluated via VITEK2 and antibiotic gradient tests, resistance genes were identified by PCR. Overall, 15.6% of the cattle harbored A. baumannii, predominantly in the nose (60.3% of the A. baumannii isolates). It was more frequent in dairy cows (21.1%) than in beef cattle (6.8%) and calves (2.4%). A seasonal occurrence was shown with a peak between May and August. The rate of occurrence of A. baumannii was correlated with a history of use of 3rd generation cephalosporins in the last 6 months prior to sampling Multilocus sequence typing (Pasteur scheme) revealed 83 STs among 126 unique isolates. Nine of the bovine STs have previously been implicated in human infections. Besides known intrinsic resistance of the species, the isolates did not show additional resistance to the antimicrobial substances tested, including carbapenems. Our data suggest that cattle are not a reservoir for nosocomial A. baumannii but carry a highly diverse population of this species. Nevertheless, some STs seem to be able to colonize both cattle and humans.

Carbapenem-resistance and pathogenicity of bovine Acinetobacter indicus-like isolates.

The objective of this study was to characterize blaOXA-23 harbouring Acinetobacter indicus-like strains from cattle including genomic and phylogenetic analyses, antimicrobial susceptibility testing and evaluation of pathogenicity in vitro and in vivo. Nasal and rectal swabs (n = 45) from cattle in Germany were screened for carbapenem-non-susceptible Acinetobacter spp. Thereby, two carbapenem resistant Acinetobacter spp. from the nasal cavities of two calves could be isolated. MALDI-TOF mass spectrometry and 16S rDNA sequencing identified these isolates as A. indicus-like. A phylogenetic tree based on partial rpoB sequences indicated closest relation of the two bovine isolates to the A. indicus type strain A648T and human clinical A. indicus isolates, while whole genome comparison revealed considerable intraspecies diversity. High mimimum inhibitory concentrations were observed for carbapenems and other antibiotics including fluoroquinolones and gentamicin. Whole genome sequencing and PCR mapping revealed that both isolates harboured blaOXA-23 localized on the chromosome and surrounded by interrupted Tn2008 transposon structures. Since the pathogenic potential of A. indicus is unknown, pathogenicity was assessed employing the Galleria (G.) mellonella infection model and an in vitro cytotoxicity assay using A549 human lung epithelial cells. Pathogenicity in vivo (G. mellonella killing assay) and in vitro (cytotoxicity assay) of the two A. indicus-like isolates was lower compared to A. baumannii ATCC 17978 and similar to A. lwoffii ATCC 15309. The reduced pathogenicity of A. indicus compared to A. baumannii correlated with the absence of important virulence genes encoding like phospholipase C1+C2, acinetobactin outer membrane protein BauA, RND-type efflux system proteins AdeRS and AdeAB or the trimeric autotransporter adhesin Ata. The emergence of carbapenem-resistant A. indicus-like strains from cattle carrying blaOXA-23 on transposable elements and revealing genetic relatedness to isolates from human clinical sources requires further investigations regarding the pathogenic potential, genomic characteristics, zoonotic risk and putative additional sources of this new Acinetobacter species.

OXA-23 and ISAba1-OXA-66 class D ß-lactamases in Acinetobacter baumannii isolates from companion animals.

Acinetobacter baumannii is recognised as a major pathogen of nosocomial infections that frequently show resistance to last-resort antimicrobials. To investigate whether A. baumannii from companion animals harbour carbapenem resistance mechanisms, 223 clinical isolates obtained from veterinary clinics between 2000 and 2013 in Germany were screened for carbapenem-non-susceptibility employing meropenem-containing Mueller-Hinton agar plates. Minimum inhibitory concentration (MIC) data were obtained using the VITEK®2 system. Assignment to international clones (ICs) was done by multiplex PCR or repetitive sequence-based PCR employing the DiversiLab system. Clonality was studied using pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Genes encoding carbapenemases and aminoglycoside-modifying enzymes were detected by PCR. In three samples from dogs, carbapenem-resistant A. baumannii carrying the blaOXA-23 gene on plasmids and located on transposon Tn2008 were identified. The isolates belonged to sequence type ST1P (clonal complex CC1/IC1/pulsotype II) and ST10P (CC10/IC8/pulsotype IV) according to the Pasteur MLST scheme, and to ST231Ox (CC109) and ST585Ox (CC447) following the Oxford scheme. Insertion sequence ISAba1 was identified upstream of blaOXA-66 in 58 A. baumannii isolates. MLST referred them to ST2P (CC2/IC2/pulsotypes I and III), ST208Ox, ST350Ox and ST556Ox (all CC118), respectively. PFGE suggested nosocomial spread of these highly related strains, which frequently demonstrated a multidrug-resistant phenotype, in one veterinary clinic. These data show that A. baumannii from companion animals reveal resistance determinants and clonal lineages of strains globally emerging in humans. This suggests an interspecies transmission and warrants molecular surveillance of A. baumannii in veterinary clinics to mitigate its further spread.

Genome sequence of OXA-23 producing Acinetobacter baumannii IHIT7853, a carbapenem-resistant strain from a cat belonging to international clone IC1.

BACKGROUND: Multidrug resistance in Acinetobacter baumannii has dramatically increased in recent years worldwide. Thus, last-line antibiotics like carbapenems are increasingly being used which in turn further augments selection pressure for resistant strains. Resistance to carbapenems in A. baumannii is frequently mediated by carbapenemases, particularly OXA-23 and OXA-58. Carbapenemase-producing bacteria are mainly described in human patients and the intestinal tract represents a common source for such pathogens. In this study, we sequenced and analyzed the genome of A. baumannii IHIT7853, a carbapenem-resistant, OXA-23 producing strain isolated from cystitis in a cat in 2000 in Germany. RESULTS: Phylogenetic analysis revealed that IHIT7853 belonged to the globally distributed international clone IC1 and MLST type ST1/ST231 (Pasteur/Oxford MLST scheme). A phylogenetic tree based on the maximum common genome of 18 A. baumannii isolates placed IHIT7853 close to human clinical isolates, such as the multidrug-resistant (MDR) outbreak strain AYE that was isolated from a patient with pneumonia and cystitis in 2001 in France. The OXA-23 plasmid sequence could be determined as 53,995 bp in size, possessing resistance genes strA and strB in addition to bla OXA-23. CONCLUSIONS: The analysis of the genome of IHIT7853 reveals that companion animals carry MDR A. baumannii that resemble relevant clonal lineages involved in severe infections in humans. As urinary tract infections are often caused by bacteria that reside in the intestinal tract, future studies should unveil, if the animal gut serves as a source for MDR A. baumannii.

Increase of angiotensin II type 1 receptor auto-antibodies in Huntington's disease.

BACKGROUND: In the recent years, a role of the immune system in Huntington's disease (HD) is increasingly recognized. Here we investigate the presence of T cell activating auto-antibodies against angiotensin II type 1 receptors (AT1R) in all stages of the disease as compared to healthy controls and patients suffering from multiple sclerosis (MS) as a prototype neurologic autoimmune disease. RESULTS: As compared to controls, MS patients show higher titers of anti-AT1R antibodies, especially in individuals with active disease. In HD, anti-AT1R antibodies are more frequent than in healthy controls or even MS and occur in 37.9% of patients with relevant titers ≥ 20 U/ml. In a correlation analysis with clinical parameters, the presence of AT1R antibodies in the sera of HD individuals inversely correlated with the age of onset and positively with the disease burden score as well as with smoking and infection. CONCLUSIONS: These data suggest a dysfunction of the adaptive immune system in HD which may be triggered by different stimuli including autoimmune responses, infection and possibly also smoking.

Progressive hepatic mitochondrial dysfunction in premanifest Huntington's disease.

BACKGROUND: A subclinical, hepatic involvement in manifest and premanifest Huntington's disease (HD) was recently demonstrated by using the (1) (3) C-methionine breath test (MeBT). In this longitudinal pilot study, we investigated whether there is evidence for progressive hepatic mitochondrial dysfunction in premanifest HD. METHODS: The MeBT was performed within a group of 25 well-characterized premanifest HD mutation carriers at baseline and in a 14.5-month follow-up. RESULTS: The total group of mutation carriers (P = 0.033; Cohen's d = 0.6) and the subgroup of mutation carriers from our PreHD-B subgroup (nearer to disease onset; P = 0.030; Cohen's d = 1.12) revealed a lower amount of exhaled (13) CO2 in the follow-up. CONCLUSIONS: This study demonstrates in vivo progressive, subclinical, hepatic involvement in premanifest HD. Limitations of the study, such as high variance in breath test results, are discussed.

Hepatic mitochondrial dysfunction in manifest and premanifest Huntington disease.

OBJECTIVE: In this cross-sectional study, we investigated whether there is evidence for hepatic mitochondrial dysfunction in manifest and/or premanifest Huntington disease (HD) by using the ¹³C-methionine breath test. METHODS: The ¹³C-methionine breath test was performed within a group of 21 patients with early manifest HD without medication, 30 premanifest mutation carriers, as well as 36 healthy controls. Premanifest mutation carriers were stratified into the 2 groups preHD-A (further from predicted onset) and preHD-B (nearer) based on a calculation of the probability of estimated disease onset within 5 years. The ¹³C-methionine breath test was performed after an overnight fasting, breath samples were analyzed by nondispersive isotope-selective infrared spectroscopy, and results expressed as percentage dose recovered after 90 minutes of testing time. Statistical analyses comprised analysis of covariance and post hoc t tests. RESULTS: Patients with manifest HD and mutation carriers from our preHD-B group revealed a lower amount of exhaled ¹³CO2 compared with healthy controls (p < 0.001 and p = 0.017, respectively). In a stepwise linear regression model, breath test results correlate to functional and cognitive scores of the Unified Huntington's Disease Rating Scale in manifest and also in premanifest HD. For all mutation carriers together, there was a weak but significant correlation of breath test results to ratio caudate volume/total intracranial volume. CONCLUSION: This study demonstrates for the first time in vivo a subclinical, hepatic involvement in manifest and premanifest HD.

Stability of cognitive functions under mitoxantrone therapy in patients with progressive multiple sclerosis: a pilot analysis.

OBJECTIVE: Mitoxantrone (MX) is a potent immunosuppressant that is licensed as escalation therapy for the treatment of active multiple sclerosis (MS). METHODS: In an open-label, retrospective analysis, we investigated effects of MX therapy on parameters of cognitive functions in patients with progressive MS and significant disability. Twenty patients received a total of 42 mg/m(2) MX in 4 cycles. Six patients who fulfilled the criteria for MX therapy, yet did not receive this treatment, served as controls. Before initiation of therapy and after a mean observation period of 24 months, neurological examination and a neuropsychological test battery were performed. Neuropsychological analyses comprised tests for cognitive flexibility as a part of executive functioning, and verbal as well as non-verbal tests for memory and attention. Additionally, intelligence and symptoms of depression were investigated. RESULTS: While there was stability of EDSS over time, there were no differences in cognitive functions before and after MX treatment. In contrast, patients not receiving MX showed a worsening of verbal short term memory and cognitive flexibility over the same time period. CONCLUSION: In conclusion, this preliminary observational study points at stability of cognitive functions under MX therapy in patients with progressive multiple sclerosis.

Upper gastrointestinal findings in Huntington's disease: patients suffer but do not complain.

We investigated, retrospectively, the prevalence of gastroesophageal inflammation in patients with Huntington's disease (HD) during 10 years in our center. We found a high prevalence of gastritis or esophagitis even in patients without complaints, indicating that gastrointestinal disease is more common in HD than patients' complaints. There was no correlation with motor disturbances but with the duration and severity of HD. Influences from the disease itself as well as secondary mechanisms like malnutrition, medication and general disability may contribute.

Analysis of the course of Parkinson's disease under dopaminergic therapy: performance of "fast tapping" is not a suitable parameter.

In addition to clinical rating scales, instrumental methods are employed frequently for assessment of performance or motor deficits in Parkinson's disease (PD). Many studies have analyzed such parameters in cross-sectional studies. We employed a battery of tests to investigate fine motor performance over a period of 4 years in 411 de novo parkinsonian patients from the Prado study. Specifically, tapping and pegboard testing ("plugging") were evaluated and performance on these tests compared with clinical ratings. Plugging scores correlated well with tapping scores and clinical rating at each assessment timepoint. Both tests also showed significant differences to healthy controls. Nevertheless "fast tapping" was found to be less impaired than was plugging in de novo patients. Over time, it was observed that plugging scores, but not tapping scores, exhibited changes that paralleled movements in clinical score. Plugging scores exhibited a marked response to dopaminergic therapy whereas fast tapping showed no therapeutic response. Fast tapping is certainly not suitable for assessment of bradykinesia or hypokinesia, and does not respond to dopaminergic therapy.