Molecular surveillance of carbapenem-resistant Enterobacterales in two nearby tertiary hospitals to identify regional spread of high-risk clones in Germany, 2019-2020.

BACKGROUND: Understanding the transmission dynamics of carbapenem-resistant Enterobacterales (CRE) is critical to addressing the escalating global threat of antimicrobial resistance (AMR). Although hospital transmission of CRE has been extensively studied, information on community transmission is lacking. AIM: To identify genomic clusters of CRE from two nearby institutions that may be indicative of community or inter-facility transmission. METHODS: CRE isolates between January 1st, 2019 and December 31st, 2020 from two tertiary hospitals, detected in the respective routine microbiology laboratories, were collected and characterized by short-read whole-genome sequencing. FINDINGS: A total of 272 CRE were collected, with Enterobacter cloacae complex (71/192, 37%) predominant in Heidelberg and Escherichia coli (19/80, 24%) in Mannheim. The most common carbapenem resistance gene, blaOXA-48, was detected in 38% of CRE from both centres. Several putative transmission clusters were found, including six clusters of E. cloacae complex, five clusters of Klebsiella pneumoniae, four clusters of Citrobacter freundii, and two clusters each of Escherichia coli and K. aerogenes. No clusters involved isolates from both study centres, except for an ST22 C. freundii cluster. Globally circulating clones were identified between the two centres for ST131 E. coli, ST66 E. hormaechei, and ST22 C. freundii. CONCLUSION: This study found no widespread transmission clusters among isolates from both centres, suggesting a hospital-specific clonal structure. This suggests that CRE clusters involving both institutions may indicate emerging or circulating clones in the community, highlighting the need for intersectoral surveillance and data sharing.

Intracranial hemorrhage in a female leading to the diagnosis of severe hemophilia A and Turner syndrome.

BACKGROUND: Severe hemophilia A (HA) in females is a very rare phenomenon. Ignoring HA as a possible diagnose can result in fatal complications. PATIENTS: We report a 3-month old girl suffering from severe hemophilia A, presenting with intracranial hemorrhage three weeks after drop down from an infant carrier. Recurrent bleeding after neurosurgery led to the diagnosis of a HA by findings of low levels of factor VIII coagulation activity (F8:C) below 1% and normal levels of factor von Willebrand activity. METHODS: Diagnosis of hemophilia A by one stage clotting test and proof by molecular studies via long - range - PCR. Chromosome analysis in metaphases from peripheral blood lymphocytes. RESULTS: Molecular analysis showed inversion of intron 22 as the result of a maternally inherited, distal, F8 gene inversion and chromosome analyses a 45,X karyotype indicative of Turner syndrome in our patient. Diagnosis was hampered by the female sex and the presence of neither a family history of bleeding disorders nor clinical signs of Turner syndrome. CONCLUSION: Our case shows that, although uncommon in female infants, x-linked genetic bleeding disorders like HA are a possible diagnosis by very different reasons. Rare bleeding disorders, although not expected, might be present and the combined clinical, laboratory and genetic analysis are needed to establish the final diagnosis. Repetitive prolonged aPTT and clinical bleeding signs should lead to further hemostasiological investigations. An algorithm for hemostasiological investigations in case of unexplained clinical bleeding is given.

Process control for enhanced L-phenylalanine production using different recombinant Escherichia coli strains.

A novel fed-batch approach for the production of L-phenylalanine (L-Phe) with recombinant E. coli is presented concerning the on-line control of the key fermentation parameters glucose and tyrosine. Two different production strains possessing either the tyrosine feedback resistant aroF(fbr) (encoding tyrosine feedback resistant DAHP-synthase (3-desoxy-D-arabino-heptusonate-7-phosphate)) or the wild-type aroF(wt) were used as model systems to elucidate the necessity of finding an individual process optimum for each genotype. With the aid of tyrosine control, wild-type aroF(wt) could be used for L-Phe production achieving higher final L-Phe titers (34 g/L) than the aroF(fbr) strain (28 g/L) and providing higher DAHP-synthase activities. With on-line glucose control, an optimum glucose concentration of 5 g/L could be identified that allowed a sufficient carbon supply for L-Phe production while at the same time an overflow metabolism leading to acetate by-product formation was avoided. The process approach is suitable for other production strains not only in lab-scale but also in pilot-scale bioreactors.

Integrated L-phenylalanine separation in an E. coli fed-batch process: from laboratory to pilot scale.

Pilot-scale reactive-extraction technology for fully integrated L-phenylalanine (L-Phe) separation in Escherichia coli fed-batch fermentations was investigated in order to prevent an inhibition of microbial L-Phe production by-product accumulation. An optimal reactive-extraction system, consisting of an organic kerosene phase with the cation-selective carrier DEHPA (di-2-ethylhexyl phosphonic acid) and an aqueous stripping phase including sulphuric acid, was found particularly efficient. Using this system with two membrane contactors, mass-transfer coefficients of up to 288 x 10(-7) cm s(-1) for the aqueous/organic and 77 x 10(-7) cm s(-1) for the organic/stripping phase were derived from experimental data using a simple modelling approach. Concentration factors higher than 4 were achieved in the stripping phase as compared to the aqueous donor phase. Reactive extraction enabled a 98% cation portion of L-Phe in the stripping phase, leading to final product purity higher than 99% after L-Phe precipitation. A doubling of L-Phe/glucose yield was observed when kerosene/DEHPA was added to the fermentation solution in the bioreactor to experimentally simulate a fully integrated L-Phe separation process.

Enhanced pilot-scale fed-batch L-phenylalanine production with recombinant Escherichia coli by fully integrated reactive extraction.

A fully integrated process for the microbial production and recovery of the aromatic amino acid L-phenylalanine is presented. Using a recombinant L-tyrosine (L-Tyr) auxotrophic Escherichia coli production strain, a fed-batch fermentation process was developed in a 20-l-scale bioreactor. Concentrations of glucose and L-Tyr were closed-loop-controlled in a fed-batch process. After achieving final L-phenylalanine (L-Phe) titres >30 g/l the process strategy was scaled up to 300-l pilot scale. In technical scale fermentation L-phenylalanine was continuously recovered via a fully integrated reactive extraction system achieving a maximum extraction rate of 110 g/h (final purity >99%). It was thus possible to increase L-Phe/glucose selectivity from 15 mol% without to 20.3 mol% with integrated product separation.

Elevated plasma concentrations of neuropeptide Y in children and adults with chronic and terminal renal failure.

Neuropeptide Y (NPY) is a peptide hormone that is expressed, stored, and released in sympathetic neurones together with noradrenaline. Elevated plasma concentrations of NPY have been reported in patients with neural crest tumors (neuroblastoma, pheochromocytoma) and following exercise. We studied plasma concentrations of NPY in children and adults with chronic and terminal renal failure and compared them with those in healthy controls. Neuropeptide Y was significantly higher in children and adolescents receiving peritoneal dialysis (5.3 +/- 2.8 pmol/L; n = 11 [mean +/- SD]) or hemodialysis (5.4 +/- 2.1 pmol/L; n = 14) than in healthy children (2.3 +/- 0.9 pmol/L; n = 19) or pediatric patients with impaired renal function who are not receiving dialysis (2.7 +/- 0.6 pmol/L; n = 8; mean glomerular filtration rate, 41 mL/min x 1.73 m2). There was a small but insignificant negative correlation between glomerular filtration rate and NPY concentrations in children with impaired renal function (r = 0.49; P = 0.25). In healthy adults, NPY concentration was similar to that in healthy children (1.8 +/- 1.0 pmol/L; n = 13), and it was significantly elevated in adults receiving hemodialysis (5.9 +/- 1.7 pmol/L; n = 16). No significant changes in NPY concentrations were found before and after hemodialysis in pediatric or adult patients. We conclude that plasma concentrations of NPY are elevated in patients with chronic renal failure who are receiving either peritoneal or hemodialysis, but not in patients with moderately impaired renal function. Whether elevated NPY concentration indicates increased sympathetic activity or is caused by reduced NPY clearance remains to be shown.

Arginine vasopressin and renin in acutely ill children: implication for fluid therapy.

The hypothesis was tested that in young children when admitted to the hospital for acute illness, vasoactive hormone levels are raised. The plasma concentration of arginine vasopressin (AVP) and plasma renin activity (PRA) were measured in 103 acutely ill infants and children admitted to the hospital. Compared to 31 control children with elective surgery, plasma AVP and PRA levels were significantly elevated and plasma osmolality reduced in acute illness, indicating non-osmotic, cardiovascular AVP release. AVP and PRA elevations were found to be independent of the underlying diseases (e.g. respiratory infections, gastroenteritis, bacterial infections and the viral syndrome). Since cardiovascular AVP activation bears the risk of hyponatraemia in the case of hypotonic fluid therapy, initial fluid management should be performed with solutions containing half-normal or normal saline in acutely ill children.

Hyponatraemia and hyperkalaemia in acute pyelonephritis without urinary tract anomalies.

UNLABELLED: Three children with severe hyponatraemia and hyperkalaemia associated with acute pyelonephritis are reported. All were very young male infants in a poor general condition and seriously dehydrated. Diagnostic procedures did not detect obstructive uropathy or vesico-ureteric reflux. CONCLUSION: Hyponatraemia and hyperkalaemia occurs in young infants with severe acute pyelonephritis in the absence of obstructive uropathy or vesico-ureteric reflux. The severe inflammation of the kidney itself may explain the electrolyte disturbance by a transient resistance of the distal tubule to aldosterone.

Clinical settings and vasopressin function in hyponatraemic children.

Hyponatraemia is one of the most common electrolyte abnormalities in hospitalised children. In a prospective study we tested whether hyponatraemia is associated with sustained release of the antidiuretic hormone arginine vasopressin (AVP). Out of 27 children with persistent hyponatremia (serum sodium < 130 mmol/l), 25 had measurable plasma concentrations of AVP [median and quartiles 5.0 pg/ml (1.5-8.3)]. Volume contraction as consequence of sodium loss caused hyponatraemia in 16 patients. Hyponatraemia in the presence of extracellular volume expansion and reduced effective arterial blood volume occurred in 5 patients. Only 3 patients had normovolaemic hyponatraemia (so-called syndrome of inappropriate antidiuretic hormone secretion) and 3 suffered from chronic renal failure. It is concluded that plasma AVP concentration is measurable in most children with hyponatraemia. Non-osmotic stimulation of AVP release and lack of suppression of this hormone is an important pathogenetic mechanism of hyponatraemia in children.