Assessing airborne transmission risks in COVID-19 hospitals by systematically monitoring SARS-CoV-2 in the air.

IMPORTANCE: Risk management and control of airborne transmission in hospitals is crucial in response to a respiratory virus pandemic. However, the formulation of these infection control measures is often based on epidemiological investigations, which are an indirect way of analyzing the transmission route of viruses. This can lead to careless omissions in infection prevention and control or excessively restrictive measures that increase the burden on healthcare workers. The study provides a starting point for standardizing transmission risk management in designated hospitals by systemically monitoring viruses in the air of typical spaces in COVID-19 hospitals. The negative results of 359 air samples in the clean and emergency zones demonstrated the existing measures to interrupt airborne transmission in a designated COVID-19 hospital. Some positive cases in the corridor of the contaminant zone during rounds and meal delivery highlighted the importance of monitoring airborne viruses for interrupting nosocomial infection.

Persistent Urinary Tract Infection in Association with Community-Acquired NDM-5 Escherichia coli Clonal Group Following COVID-19 Infection - Beijing Municipality, China, 2023.

What is already known about this topic?: The hospital-acquired infections caused by New Delhi metallo-beta-lactamase (NDM)-producing strains are typically attributed to a single clonal lineage. What is added by this report?: In this study, we encountered a unique case of community-acquired NDM-5 Escherichia coli urinary tract infection (UTI) following coronavirus disease 2019 (COVID-19). The UTI persisted for a duration of at least 45 days. Genomic analyses revealed the presence of two NDM-5 strains, both sharing an identical chromosomal background but distinct, homologous, and recombined plasmids. This case suggests that a diverse range of resistance genes may be present within the human body, with drug-resistant strains undergoing continuous evolution during infection. The intestinal tract may have been its drug-resistant gene pool. What are the implications for public health practice?: The observations presented in this case indicate that the endogenous acquisition of drug-resistant genes may also be an issue in managing multidrug-resistant organisms (MDRO). It is possible for continuous recombination to occur within carbapenem-resistant Enterobacteriaceae (CRE) during infection. In contrast to exogenously-acquired resistance, greater attention should be placed on the endogenous factors that contribute to the development of CRE within healthcare settings.

An ultrasensitive and rapid "sample-to-answer" microsystem for on-site monitoring of SARS-CoV-2 in aerosols using "in situ" tetra-primer recombinase polymerase amplification.

Airborne transmissibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the urgent need for aerosol monitoring of SARS-CoV-2 to prevent sporadic outbreaks of COVID-19. The inadequate sensitivity of conventional methods and the lack of an on-site detection system limited the practical SARS-CoV-2 monitoring of aerosols in public spaces. We have developed a novel SARS-CoV-2-in-aerosol monitoring system (SIAMs) which consists of multiple portable cyclone samplers for collecting aerosols from several venues and a sensitive "sample-to-answer" microsystem employing an integrated cartridge for the analysis of SARS-CoV-2 in aerosols (iCASA) near the sampling site. By seamlessly combining viral RNA extraction based on a chitosan-modified quartz filter and "in situ" tetra-primer recombinase polymerase amplification (tpRPA) into an integrated microfluidic cartridge, iCASA can provide an ultra-high sensitivity of 20 copies/mL, which is nearly one order of magnitude greater than that of the commercial kit, and a short turnaround time of 25 min. By testing various clinical samples of nasopharyngeal swabs, saliva, and exhaled breath condensates obtained from 23 COVID-19 patients, we demonstrate that the positive rate of our system was 3.3 times higher than those of the conventional method. Combining with multiple portable cyclone samplers, we detected 52.2% (12/23) of the aerosol samples, six times higher than that of the commercial kit, collected from the isolation wards of COVID-19 patients, demonstrating the excellent performance of our system for SARS-CoV-2-in-aerosol monitoring. We envision the broad application of our microsystem in aerosol monitoring for fighting the COVID-19 pandemic.

Coronavirus Disease 2019 Patients in Earlier Stages Exhaled Millions of Severe Acute Respiratory Syndrome Coronavirus 2 Per Hour.

Coronavirus disease 2019 (COVID-19) patients exhaled millions of severe acute respiratory syndrome coronavirus 2 RNA copies per hour, which plays an important role in COVID-19 transmission. Exhaled breath had a higher positive rate (26.9%, n = 52) than surface (5.4%, n = 242) and air (3.8%, n = 26) samples.

Diluted conventional media improve the microbial cultivability from aquarium seawater.

The cultivation of microbial species remains a primary challenge in microbiology and obtaining pure cultures is essential for the study of microbial physiology and function. When isolating microorganisms from aquaculture environments, Vibrio are the most dominate isolates on the media that are commonly used. In order to expand our ability to study microbial species, an easy-operation and low-cost medium that can reduce the interference of Vibrio strains and increase the cultivability of other bacteria is urgently needed. We compared viable cell counts on conventional media (CM; including Marine Agar 2216 and LB media) and diluted media (DM; including 1/10-Marine Agar 2216, 1/10-LB). We also assessed the diversity of cultivable microorganisms under high and low nutrient conditions by a plate-wash strategy coupled with high-throughput sequencing of the V4 hypervariable region of the 16S rRNA gene. The results show that microbial communities from DM, especially 1/10-Marine Agar 2216, are more diverse than those obtained from CM. Vibrio isolates were reduced on DM. PICRUSt analysis revealed that nutrient composition is a significant contributor to the diversity and function of the cultivable microbial communities. Bacteria grown on CM possess more pathogenic characteristics, whereas DM favors the growth of bacteria that have multiple metabolic functions. Collectively, our data provide strong evidence that dilution of CM influences the cultivability of bacteria from aquaculture seawater. It also supports that DM can expand the range of microbial species that can be cultivated. This study also provides insights for media design in microbial cultivation from aquaculture systems.

The abundant marine bacterium Pelagibacter simultaneously catabolizes dimethylsulfoniopropionate to the gases dimethyl sulfide and methanethiol.

Marine phytoplankton produce ∼10(9) tonnes of dimethylsulfoniopropionate (DMSP) per year(1,2), an estimated 10% of which is catabolized by bacteria through the DMSP cleavage pathway to the climatically active gas dimethyl sulfide(3,4). SAR11 Alphaproteobacteria (order Pelagibacterales), the most abundant chemo-organotrophic bacteria in the oceans, have been shown to assimilate DMSP into biomass, thereby supplying this cell's unusual requirement for reduced sulfur(5,6). Here, we report that Pelagibacter HTCC1062 produces the gas methanethiol, and that a second DMSP catabolic pathway, mediated by a cupin-like DMSP lyase, DddK, simultaneously shunts as much as 59% of DMSP uptake to dimethyl sulfide production. We propose a model in which the allocation of DMSP between these pathways is kinetically controlled to release increasing amounts of dimethyl sulfide as the supply of DMSP exceeds cellular sulfur demands for biosynthesis.

[Glucocorticoid in the treatment of severe acute respiratory syndrome patients: a preliminary report].

OBJECTIVE: To discuss the effect of glucocorticoid (methylprednisolone) on severe acute respiratory syndrome (SARS). METHODS: Thirty SARS patients were treated at our hospital for over 3 weeks since March to May 2003. The course and dosage of glucocorticoid, counts of CD(4)(+), CD(8)(+) and CD(3)(+), electrolytes, blood routine, and sera albumin before and after the treatment were analysed. RESULTS: Before treatment by methylprednisolone, the counts of CD(4)(+), CD(8)(+) and CD(3)(+) of 27 SARS patients were (401 +/- 203), (340 +/- 187), (756 +/- 383) cells/ microl. Twenty-nine of the 30 SARS patients were treated by methylprednisolone. The dosage for 24 patients was 80 - 160 mg/d with the largest being 1,000 mg/d before admission to the hospital. The count of WBC was increased after treatment (P < 0.01). No obvious effect was observed on the potassium, sodium and chlorine of blood (P > 0.05). Glucocorticoid increased the level of blood glucose (P = 0.01), decreased the level of sera albumin (P < 0.01), and its large dosage decreased the counts of CD(4)(+), CD(8)(+) and CD(3)(+). Three severe patients had secondary infection after administration of a large dose of glucocorticoid. CONCLUSIONS: In the early stage of the disease, the counts of CD(4)(+), CD(8)(+) and CD(3)(+) of SARS patients may reduce markedly indicating the immunity is suppressed. A large dose of glucocorticoid may aggravate the suppression and make the body in an active metabolic state (the increase of blood glucose and the decrease of sera albumin). Thus the disease is aggravated and patients are likely to suffer from severe secondary infection. Indications for use of glucocorticoid must strictly controlled and its large dosage is improper.

[Clinical analysis of SARS: 27 cases report].

OBJECTIVE: To realize the clinical characteristic of severe acute respiratory syndrome (SARS). METHODS: Observe the clinical signs and symptoms of each patients; do laboratory examination periodically; and at last do Stat analysis of all the cases. RESULTS: The first onset symptom of the 27 cases is high fever accompany with toxic symptom such as muscular soreness, headache, etc. The patient's condition may be most serious in the 2nd week. The amount of end-brush blood WBC decrease, especially the lymphocyte decrease more obviously. The amount of CD(4)(+) and CD(8)(+) decrease obviously is another important characteristic. The chest X-ray show pulmonary lesion in the 2nd day after onset of the illness, but 40.7% cases show positive change after 6 days onset. During the 7 - 12 days the pulmonary lesion become most serious. Seven cases are treated by steroid in the first 3 days when the chest X-ray is normal, but they become positive during 6 - 8 days of the course. Whether the state of the illness is serious or not seems no obvious relationship to when they are treated by steroid. And large dosage of steroid may inhibit the level of CD(4)(+) and CD8 (P < 0.05). Two severe cases present double infection after large dosage of steroid. CONCLUSION: The course of a infectious atypical pneumonia is almost 3 weeks, the 1st week can be decided as early stage, the 2nd week is decided as fastigium, the 3rd week is decided as stage of recovery. During the fastigium, the disease transform very quickly, we need pay more attention to the patient. The CD(4)(+), CD(8)(+) and CD(3)(+) of SARS patient decrease obviously, it seems the immuno-function inhibited seriously. The serious case is easily accompany with severe secondary infection in the late stage, so the use of steroid must be carefully and the dosage need not to be much more.