Bacterial contamination of water used as thermal transfer fluid in fluid-warming devices.

INTRODUCTION: Recent reports implicated heater-cooler units (HCUs), which are used for warming infusions, blood or in extracorporeal membrane oxygenation devices, as a possible origin of healthcare-associated infections (HAIs) with potentially pathogenic bacteria, such as non-tuberculous mycobacteria [1]. This represents a source of contamination in a usually sterile setting. AIM: To analyse water from infusion heating devices (IHDs) for bacterial contamination, and to determine if IHDs are a potential source in the transmission of HAIs. METHODS: Thermal transfer fluid (TTF; 300-500 mL) was collected from the reservoirs of 22 independent IHDs and processed on different selective and non-selective media for colony count and identification of bacteria. Strains of Mycobacterium spp. were analysed by whole-genome sequencing. RESULTS: Bacterial growth was observed in all 22 TTF samples after cultivation at 22 °C and 36 °C. Pseudomonas aeruginosa was the most frequent pathogen identified, present in 13.64% (3/22) of samples at >100 colony-forming units/100 mL. Colonization with Mycobacterium chimaera, Ralstonia pickettii and Ralstonia mannitolilytica was detectable in 9.09% (2/22) of samples. Primary sequencing of the detected M. chimaera suggests a close relationship with a M. chimaera strain detected in an outbreak in Switzerland which led to the death of two patients. DISCUSSION: Contamination of TTF represents a germ reservoir in a sensitive setting. Handling errors of IHDs may lead to the distribution of opportunistic or facultative bacterial pathogens, increasing the risk of transmission of nosocomial infections.

A case of fulminant respiratory diphtheria in a 24-year-old Afghan refugee in Austria in May 2022: a case report.

PURPOSE: Raising awareness of respiratory diphtheria and for the importance of early antitoxin administration. METHODS: Report of a case of fulminant, imported respiratory diphtheria in an otherwise healthy 24-year-old Afghan refugee in Austria in May 2022. RESULT: This was the first case of respiratory diphtheria in Austria since 1993. Diphtheria antitoxin was administered at an already progressed disease stage. This delay contributed to a fulminant disease course with multiorgan failure and death. CONCLUSION: In high-income countries with low case numbers, awareness of respiratory diphtheria and for the importance of early antitoxin administration must be raised.

Peptostreptococcus anaerobius: Pathogenicity, identification, and antimicrobial susceptibility. Review of monobacterial infections and addition of a case of urinary tract infection directly identified from a urine sample by MALDI-TOF MS.

Peptostreptococcus anaerobius is a gram-positive anaerobic coccus (GPAC) found in the gastrointestinal and vaginal microbiota. The organism is mainly found in polymicrobial and scarcely in monobacterial infections such as prosthetic and native endocarditis. Anaerobic bacteria have rarely been reported as the cause of urinary tract infection (UTI). Although GPAC are susceptible to most antimicrobials used against anaerobic infections, P. anaerobius has shown to be more resistant. Herein, we report a case of UTI caused by P. anaerobius from a 62-year-old man with a history of urological disease. Surprisingly, the microorganism was directly identified by Matrix-Assisted Laser Desorption-Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) from the urine sample. The isolate was successfully identified by phenotypic methods, MALDI-TOF MS, and 16S rRNA gene sequencing. P. anaerobius showed no ß-lactamase-producing activity, was resistant to penicillin, ampicillin, ciprofloxacin and levofloxacin, and displayed intermediate susceptibility to ampicillin-sulbactam and amoxicillin-clavulanic acid. Successful treatment was achieved with oral amoxicillin-clavulanic acid. Antimicrobial susceptibility testing (AST) should be performed on P. anaerobius isolates due to their unpredictable AST patterns and because empirically administered antimicrobial agents may not be active. This report shows that MALDI-TOF MS, directly used in urine specimens, may be a quick option to diagnose UTI caused by P. anaerobius or other anaerobic bacteria. This review is a compilation of monobacterial infections caused by P. anaerobius published in the literature, their pathogenicity, identification, and data about the antimicrobial susceptibility of P. anaerobius.

Enhancing the synthesis of latex clearing protein by different cultivation strategies.

In this study, we improved the synthesis of the latex clearing protein from Gordonia polyisoprenivorans VH2 (Lcp1VH2), a key enzyme for the initial cleavage of the rubber backbone. Cultivations using a recombinant strain of Escherichia coli were optimized to overcome poor solubility of Lcp1VH2 and improve the production yields. Different cultivation temperatures and agitation rates were evaluated in the process to demonstrate their impact on the solubility of Lcp1VH2. A specific maximum production rate of 28.3 mg Lcp1VH2 g-1 cell dry weight h-1 was obtained at 25 °C and at agitation rates between 200-300 rpm. The activity of Lcp1VH2 was strongly influenced by variations in the cultivation temperature with a specific maximum activity of 0.81 U mg-1 in cultures incubated at 30 °C. Besides cultivation-based optimization, also the strategy of fusion protein expression with NusA was successfully applied. The in vivo solubility of the Lcp1VH2 fusion protein was calculated to be 73.1%, which means an enhancement of 5.7-fold in comparison to the solubility of the native Lcp1VH2. The fusion protein of Lcp1VH2 and NusA still exhibited oxygenase activity with polyisoprene latex as a substrate. In fact, NusA-His-Lcp1VH2 reached a 4-fold higher volumetric activity in comparison to Lcp1VH2. Oligo(cis-1,4-isoprene) molecules were produced as degradation products due to the cleavage of the polymer backbone by NusA-His-Lcp1VH2. The formation of oligo-isoprenoid molecules with molecular weights between 236 and 984 Da were confirmed by electrospray ionization-mass spectrometry analysis.

[Long-term results of stapes surgery with the Schuknecht wire-teflon prosthesis]. / Langzeitergebnisse der Stapesplastik mit der Schuknecht-Draht-Teflon-Prothese.

Early and late postoperative findings in 78 cases of stapedial surgery with 0.6 mm Schuknecht Teflon Wire Pistons only, performed from 1983 to 1987, were analysed to evaluate the supposition of an inverse relationship of the size of the footplate fenestration and functional long-term results. In respect of the size of fenestration our surgical strategy resulted in 3 different situations: stapedotomy (26)--partial platinectomy (34)--stapedectomy (19). Mean air conduction thresholds for frequencies 0.5-4 kHz were evaluated preoperatively, one month and > 5 years postoperatively. The results were postoperatively significantly better in all 3 groups without significant intergroup differences. > 5 years postoperatively the best results were seen in the partial platinectomy group better than after stapedotomy and significantly better than in the stapedectomy group. With regard to overclosure, closure of the air bone gap and deterioration of bone conduction thresholds at 4 kHz for the same groups, no significant differences were noticed. In conclusion, the best long-term results were obtained after partial platinectomy, i.e. there was no inverse relation of the size of the footplate perforation and the best results. The perforation should be large enough to prevent tilting of the piston at the edge. Removal of larger parts should be omitted. In case of early mobilisation and stapedectomy good long-term results can still be expected.