Molecular characterization of Escherichia coli isolates recovered from broilers with cellulitis.

Avian cellulitis in broilers, caused by avian pathogenic Escherichia coli, is a major cause for carcass rejections during meat inspection, resulting in significant economic losses. In this study, we analysed E. coli isolates obtained from broiler chickens affected by cellulitis for their genetic relatedness and antimicrobial resistance phenotype and genotype. The objective was to determine whether there is a clonal spread or whether these clinical isolates differ. For this purpose, E. coli was isolated from swab samples collected from diseased broilers across 77 poultry farms in Germany, resulting in 107 isolates. These isolates were subjected to serotyping, PCR-based phylotyping and macrorestriction analysis with subsequent pulsed-field gel-electrophoresis for typing purposes. In addition, the presence of virulence genes associated with avian pathogenic E. coli (APEC) was investigated by PCR. Antimicrobial susceptibility of the isolates was examined by the disk diffusion method according to CLSI guidelines and subsequently, the presence of corresponding resistance genes was investigated by PCR. Typing results revealed that a significant proportion of the isolates belonged to serotype O78:K80, which is one of the major APEC serotypes. Phylogenetic grouping showed that phylogenetic group D was most commonly represented (n = 49). Macrorestriction analysis showed overall heterogenous results, however, some clustering of closely related isolates was observed. The level of antimicrobial resistance was high, with 83.8% of isolates non-susceptible to at least one class of antimicrobial agents and 40% of isolates showing resistance to at least three classes. The most frequently observed resistance was to ampicillin, mediated by blaTEM (n = 56). However, few isolates were non-susceptible to ciprofloxacin (n = 8) and none of the isolates was resistant to 3rd generation cephalosporins or carbapenems. Overall, the results show that genetically diverse APEC associated with avian cellulitis can be found among and within German poultry farms. While most isolates were antimicrobial resistant, resistance levels to high(est) priority critically important antimicrobials were low.

Management factors influencing the occurrence of cellulitis in broiler chickens.

One of the main reasons for condemning fattening broiler chickens during meat inspection is cellulitis, which demonstrates the great economic issue concerning this topic. The aim of this epidemiological study was therefore to identify risk factors in order to draw conclusions on how to prevent the occurrence of cellulitis in broilers by implementing management changes. The data were collected between April and November 2018 on conventional broiler farms (n = 100) in the north of Germany with one to fourteen poultry houses per farm. In total, data were collected from 199 broiler flocks with a total of 5,332,767 broilers. Data on the type of management (feeding- and drinking management, housing, lighting management, litter type and animal health) were collected via a questionnaire, with additional data on condemnation rates being provided by the abattoirs. It was found that litter additives like fennel, eucalyptus and probiotics as well as a moist litter quality were associated with lower cellulitis condemnation rates. Flocks fattened in windowless barns, but with relatively higher lux-values as well as those broilers examined in a lower number of housing inspections had significantly lower cellulitis condemnation rates compared to other husbandry systems. In addition, lower cellulitis rates were seen when housing capacities were smaller, regardless of stocking density. The source of the breeders and hatchery also had a significant influence on the occurrence of cellulitis. No correlation was found between the condemnation rates due to cellulitis and the performance of thinning, the water source used, the use of drinking additives, observational skills and number of herd managers monitoring the broilers, participation in an animal welfare programme, the technique of heating and ventilation systems used, the feed supplier, litter material, the broiler breed, the length of darkness periods and chick losses during the first seven days. We concluded that management decisions that lead to stress reduction in the broiler flocks are beneficial in terms of chicken welfare and occurrence of cellulitis.

How does symmetry impact the flexibility of proteins?

It is well known that (i) the flexibility and rigidity of proteins are central to their function, (ii) a number of oligomers with several copies of individual protein chains assemble with symmetry in the native state and (iii) added symmetry sometimes leads to added flexibility in structures. We observe that the most common symmetry classes of protein oligomers are also the symmetry classes that lead to increased flexibility in certain three-dimensional structures-and investigate the possible significance of this coincidence. This builds on the well-developed theory of generic rigidity of body-bar frameworks, which permits an analysis of the rigidity and flexibility of molecular structures such as proteins via fast combinatorial algorithms. In particular, we outline some very simple counting rules and possible algorithmic extensions that allow us to predict continuous symmetry-preserving motions in body-bar frameworks that possess non-trivial point-group symmetry. For simplicity, we focus on dimers, which typically assemble with twofold rotational axes, and often have allosteric function that requires motions to link distant sites on the two protein chains.

Molecular karyotyping as a relevant diagnostic tool in children with growth retardation with Silver-Russell features.

OBJECTIVE: To determine the contribution of submicroscopic chromosomal imbalances to the etiology of Silver-Russell syndrome (SRS) and SRS-like phenotypes. STUDY DESIGN: We performed molecular karyotyping in 41 patients with SRS or SRS-like features without known chromosome 7 and 11 defects using the Affymetrix SNP Array 6.0 system (Affymetrix, High Wycombe, United Kingdom). RESULTS: In 8 patients, pathogenic copy number variations with sizes ranging from 672 kb to 9.158 Mb were identified. The deletions in 1q21, 15q26, 17p13, and 22q11 were associated with known microdeletion syndromes with overlapping features with SRS. The duplications in 22q13 and Xq25q27 represent unique novel copy number variations but have an obvious influence on the phenotype. In 5 additional patients, the pathogenetic relevance of the detected variants remained unclear. CONCLUSION: Pathogenic submicroscopic imbalances were detectable in a significant proportion of patients with short stature and features reminiscent of SRS. Therefore, molecular karyotyping should be implemented in routine diagnostics for growth-retarded patients with even slight dysmorphisms suggestive for SRS.

Detection of autosomal dominant polycystic kidney disease by NMR spectroscopic fingerprinting of urine.

Autosomal dominant polycystic kidney disease (ADPKD) is a frequent cause of kidney failure; however, urinary biomarkers for the disease are lacking. In a step towards identifying such markers, we used multidimensional-multinuclear nuclear magnetic resonance (NMR) spectroscopy with support vector machine-based classification and analyzed urine specimens of 54 patients with ADPKD and slightly reduced estimated glomerular filtration rates. Within this cohort, 35 received medication for arterial hypertension and 19 did not. The results were compared with NMR profiles of 46 healthy volunteers, 10 ADPKD patients on hemodialysis with residual renal function, 16 kidney transplant patients, and 52 type 2 diabetic patients with chronic kidney disease. Based on the average of 51 out of 701 NMR features, we could reliably discriminate ADPKD patients with moderately advanced disease from ADPKD patients with end-stage renal disease, patients with chronic kidney disease of other etiologies, and healthy probands with an accuracy of >80%. Of the 35 patients with ADPKD receiving medication for hypertension, most showed increased excretion of proteins and also methanol. In contrast, elevated urinary methanol was not found in any of the control and other patient groups. Thus, we found that NMR fingerprinting of urine differentiates ADPKD from several other kidney diseases and individuals with normal kidney function. The diagnostic and prognostic potential of these profiles requires further evaluation.

A promoter polymorphism of the alpha 8 integrin gene and the progression of autosomal-dominant polycystic kidney disease.

BACKGROUND/AIMS: Dysregulation of integrins is a feature of tissue remodeling in autosomal-dominant polycystic kidney disease (ADPKD). The alpha 8 beta 1 integrin (alpha8beta1) affects kidney development and the susceptibility to renal injury in mice. We investigated whether the -414 T/C polymorphism in the promoter region of the alpha 8 integrin chain gene (ITGA8) is associated with the progression of renal disease in ADPKD. METHODS: Genotyping for the -414 T/C polymorphism was performed by allelic separation using RT-PCR in 294 patients with ADPKD. Alpha 8 integrin expression was detected by RT-PCR and immunohistochemistry. RESULTS: 41% of the study population reached end stage renal disease at a mean age of 51 +/- 12 years. The frequency of the -414 C allele was 0.194 in ADPKD. C allele carriers (CC and TC genotypes) were compared with patients homozygous for the T allele (TT genotype). Kaplan-Meier analysis revealed that end-stage renal failure occurred at a significantly younger age in TT homozygotes (median age, 47 years; 95% CI, 46-49 years) than in C allele carriers (median age, 51 years; 95% CI, 49-53 years; p = 0.046 by the log-rank test). When parameters of ADPKD patients were compared between genotype by analysis of variance, only age at onset of end-stage renal failure was significantly different (p = 0.026) whereas age at onset of hypertension, body surface area, 24-hour systolic and diastolic blood pressure did not differ. In kidneys of ADPKD, expression of alpha 8 integrin is increased and found de novo in cystic epithelia. CONCLUSION: A polymorphism of the ITGA8 promoter modifies the progression of renal failure in ADPKD.

Renal and cardiac effects of antihypertensive treatment with ramipril vs metoprolol in autosomal dominant polycystic kidney disease.

BACKGROUND: Hypertension is a common complication in autosomal dominant polycystic kidney disease (ADPKD). This prospective randomized double-blind study was performed to compare the renal and cardiac effects of the ACE inhibitor ramipril and the beta-blocker metoprolol as first line therapy in ADPKD patients with hypertension. METHODS: Forty-six hypertensive ADPKD patients were randomized to either ramipril (n = 23) or metoprolol (n = 23). Twenty-four hour (24-h) ambulatory blood pressure (BP), glomerular filtration rate (GFR) as calculated by the Cockcroft and Gault formula, urinary albumin excretion (albumin/creatinine ratio), and left ventricular mass index (LVMI) were established at baseline and at yearly intervals. The total follow-up was 3 years. Baseline characteristics were similar in both groups. RESULTS: Mean arterial pressure (MAP) decreased significantly in both the ramipril and the metoprolol group (-8 +/- 2 and -6 +/- 2 mmHg; both P < 0.01). There was a significant decline in renal function during follow-up which was similar in patients treated with ramipril or metoprolol (-2.5 +/- 0.7 vs -2.9 +/- 0.8 ml/min/year; P = NS). After the 3 years follow-up, no differences in GFR, LVMI and urinary albumin excretion were observed between the ramipril and the metoprolol group (80.7 +/- 10.7 vs 78.0 +/- 7.6 ml/min, 102.6 +/- 6.8 vs 100.3 +/- 5.4 g/m(2); and 42.6 +/- 12.3 vs 70.3 +/- 32.5 mg/g, respectively; all P = NS). A post-hoc analysis evaluating the effects of BP control, revealed that LVMI increased in patients with standard BP control while it remained stable in patients with rigorous BP control with a significant difference in LVMI between the groups after 3 years of follow-up (110.5 +/- 6.3 vs 90.9 +/- 4.7 g/m(2); P = 0.017). Also, by the end of the study albuminuria was lower in patients with rigorous vs standard BP control (23.5 +/- 6.7 vs 94.8 +/- 35.4 mg/g; P = 0.05). CONCLUSIONS: In our study population of hypertensive ADPKD patients, no differences in renal function, urinary albumin excretion and LVMI were detected between those treated with ramipril or metoprolol, respectively, during a 3 years follow-up. Rigorous BP control prevented an increase in LVMI and reduced urinary albumin excretion, suggesting a crucial role of BP control for slowing progression of cardiac and renal organ damage in ADPKD.

[Urine diagnosis and leukocyturia]. / Blase, Niere oder gar der Blinddarm? Nicht hinter jeder Leukozyturie steckt ein Harnwegsinfekt.

The most common cause of leukocyturia is--in conjunction with bacteriuria--an infection of the urinary tract. In the sediment, leukocytes may be differentiated into neutrophil or eosinophil granulocytes or lymphocytes. When contamination has been excluded, leukocyturia in the absence of significant bacteriuria mandates a further diagnostic evaluation. Of necessity for an accurate diagnostic work-up are appropriate urine sampling, rapid examination of the samples obtained, and standardized examination conditions.

Intracranial aneurysms and dolichoectasia in autosomal dominant polycystic kidney disease.

BACKGROUND: Intracranial saccular aneurysms (ICA) are a known extrarenal manifestation of autosomal dominant polycystic kidney disease (ADPKD). In order to facilitate the definition of subgroups who are at risk for ICA and to determine the prevalence of ICA in these subgroups we studied ADPKD patients with a positive family history for a cerebral event, including cerebral stroke (group I) and intracranial bleeding or known ICA (group II). METHODS: Within an enrolment period of 21 months, 43 ADPKD patients from our outpatient clinic and hospital were examined with cerebral magnetic resonance angiography (MRA). RESULTS: ICA were detected in six patients (14%). Three out of 32 patients (9.4%) in group I and three out of 11 patients (27.3%) in group II had an ICA. A dolichoectasia of intracerebral vessels was found in two out of 43 patients (4.7%). CONCLUSIONS: Using MRA a high prevalence of ICA was shown only in patients with a family history of cerebral bleeding or ICA. A family history for cerebral stroke does not imply an elevated risk for ICA. However, dolichoectasia, rare in the normal population, was detected in two patients. We recommend screening for ICA in patients with a positive family history for cerebral bleeding or ICA. Because of potential complications, examiners should direct their attention to dolichoectasia in ADPKD patients.