SciCombinator

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Journal: International journal of antimicrobial agents

21

SARS-CoV-2, the novel coronavirus from China, is spreading around the world, causing a huge reaction despite its current low incidence outside China and the Far East. Four common coronaviruses are in current circulation and cause millions of cases worldwide. This article compares the incidence and mortality rates of these four common coronaviruses with those of SARS-COV-2 in Organisation for Economic Co-operation and Development countries. It is concluded that the problem of SARS-CoV-2 is probably being overestimated, as 2.6 million people die of respiratory infections each year compared with less than 4000 deaths for SARS-CoV-2 at the time of writing.

18

Wound bioburden plays an important role in impaired healing and the development of infection-related complications. The objective of this study was to determine the efficacy of an innovative two-layer nitric oxide generating system (NOx) to prevent and treat biofilms formed by bacterial and fungal pathogens commonly associated with wound infection, and activity against Pseudomonas aeruginosa virulence factors. Single and mixed species biofilms were grown for 24h on nitrocellulose filters placed on agar. Filters were covered with either NOx or placebo, before and after biofilm formation. Populations of bacteria and yeasts were determined using viable counts. Pyocyanin and elastase production from P. aeruginosa were determined in supernatants derived from suspended biofilms. Efficacy of NOx was demonstrated against Staphylococcus aureus, P. aeruginosa, Acinetobacter baumannii, Escherichia coli and Candida spp. Population reductions between 2 and 10 log fold were observed. Pyocyanin and elastase activities from P. aeruginosa were reduced 1.9 and 3.2-fold respectively. This study demonstrated activity of NOx against formation and treatment of single and mixed species biofilms, including multi-drug resistant strains. NOx represents a new generation of antimicrobial agent with potent, broad-spectrum activity, and with no evidence of resistance development.

Concepts: Immune system, Bacteria, Microbiology, Antibiotic resistance, Pseudomonas aeruginosa, Biofilm, Quorum sensing, Pseudomonadales

15

Bacterial communities are exposed to a cocktail of antimicrobial agents, including antibiotics, heavy metals and biocidal antimicrobials such as quaternary ammonium compounds (QACs). The extent to which these compounds may select or co-select for antimicrobial resistance (AMR) is not fully understood. In this study, human associated, wastewater derived, bacterial communities were exposed to either benzalkonium chloride (BAC), ciprofloxacin or trimethoprim at sub-point of use concentrations for one week, in order to determine selective and co-selective potential. Metagenome analyses were performed to determine effects on bacterial community structure and prevalence of antibiotic resistance genes (ARGs) and metal or biocide resistance genes (MBRGS). Ciprofloxacin had the greatest co-selective potential, significantly enriching for resistance mechanisms to multiple antibiotic classes. Conversely, BAC exposure significantly reduced relative abundance of ARGs and MBRGS, including the well characterised qac efflux genes. However, BAC exposure significantly impacted bacterial community structure. This suggests BAC and potentially other QACs did not play as significant a role in co-selection for AMR relative to antibiotics such as ciprofloxacin at below point of use concentrations in this study. This approach can be used to identify priority compounds for further study, to better understand evolution of AMR in bacterial communities exposed to sub-point of use concentrations of antimicrobials.

14

In December 2019, a new coronavirus, named SARS-CoV-2, has emerged from China causing pneumonia outbreaks first in the Wuhan region and have now spread worldwide because of its probable high transmission efficiency. Due to the lack of efficient and specific treatments and the need to contain the epidemic, drug repurposing appears to be the best tool to find therapeutic solution. Chloroquine, remdesivir, lopinavir, ribavirin or ritonavir have shown efficacy to inhibit coronavirus in vitro. Teicoplanin, an antibiotic used to treat staphylococci infection, previously showed efficacy to inhibit the first stage of MERS-coronarivus viral cycle in human cells. This activity is conserved on the SARS-Cov-2, thus placing teicoplanin as a potential treatment for patients with this virus.

9

Growing data suggest that antibiotic-resistant bacterial infections are common in low and middle-income countries. This review summarizes the microbiology of key bacterial syndromes encountered in West Africa and estimates the prevalence of antimicrobial resistance (AMR) that could compromise first-line empirical treatment.

Concepts: Bacteria, Virus, Staphylococcus aureus, Antibiotic resistance, Escherichia coli, Microorganism, Penicillin, Clostridium difficile

7

Emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously provisionally named 2019 novel coronavirus or 2019-nCoV) disease (COVID-19) in China at the end of 2019, has caused a large global outbreak and a major public health issue. As of February 11, 2020, data from the WHO has shown that more than 43,000 confirmed cases have been identified in 28 countries/regions, with more than 99% of the cases being detected in China. On January 30, 2020, WHO has declared COVID-19 as the sixth public health emergency of international concern. The SARS-CoV-2 is closely related to two bat-derived severe acute respiratory syndrome-like coronaviruses, bat-SL-CoVZC45 and bat-SL-CoVZXC21. It is spread by human-to-human transmission via droplets or direct contact, and infection has been estimated to have mean incubation period of 6.4 days and a basic reproduction number of 2.24-3.58. Among the patients with pneumonia caused by the SARS-CoV-2 (novel coronavirus pneumonia or Wuhan pneumonia), fever was the most common symptom, followed by cough. Bilateral lung involvement with ground glass opacity was the most common finding from computerized tomography images of the chest. Although the one case of SARS-CoV-2 pneumonia in the United States responding well to remdesivir, which is now undergoing a clinical trial in China. Currently, controlling infection to prevent the spread of the SARS-CoV-2 is the primary intervention being used. However, public health authorities should keep monitoring the situation closely, as the more we can learn about this novel virus and its associated outbreak, the better we can respond.

7

There are substantial limitations in our understanding of the distribution of antibiotic resistance (AMR) in humans and livestock in developing countries. Here, we present the results of an epidemiological study examining patterns of AMR in Escherichia coli isolates circulating in sympatric human (n=321) and livestock (n=633) samples from 99 households across Nairobi, Kenya. E. coli isolates were tested for susceptibility to 13 antimicrobial drugs representing 9 antibiotic classes. We detected high rates of AMR, with 47.6% and 21.1% of isolates displaying resistance to ≥ 3 and ≥5 antibiotic classes respectively. Human isolates showed higher levels of resistance to sulfonamides, trimethoprim, aminoglycosides and penicillins compared to livestock (p<0.01), while poultry isolates were more resistant to tetracyclines (p=0.01) compared to humans. The most common co-resistant phenotype observed was to tetracyclines, streptomycin and trimethoprim (30.5%). At the household level, AMR carriage in humans was associated with human density (p<0.01) and the presence of livestock manure (p=0.03), but livestock keeping on its own had no influence on human AMR carriage (p>0.05). Our findings revealed a high prevalence of AMR E. coli circulating in healthy humans and livestock in Nairobi, with no evidence to suggest that keeping livestock, when treated as a single risk factor significantly contributed to the burden of AMR in humans, although the presence of livestock waste was significant. These results provide an understanding of the broader epidemiology of AMR in complex, and interconnected urban environments.

6

The clinical experience of ceftaroline fosamil (CPT-F) therapy for gram-positive infective endocarditis is reported from CAPTURE, a retrospective study conducted in the United States.

3

It has been 2 months since the first case of coronavirus disease 2019 (COVID-19) was reported in Wuhan. So far, COVID-19 has affected 84,503 patients in 57 countries/territories and caused 2,924 deaths in nine countries. However, the epidemiology data differ across countries. Although China had higher morbidity and mortality than other sites, the number of new cases per day in China is lesser than that outside of China since February 26, 2020. The incidence ranged from 61.4 per 1,000,000 people in Republic of Korea to 0.0002 per 1,000,000 people in India. The daily cumulative index (DCI) of COVID-19 (cumulative cases/no. of days between the first reported case and February 29, 2020) was greatest in China (1,320.85 per day), followed by Republic of Korea (78.78 per day), Iran (43.11 per day), and Italy (30.62 per day). However, the DCI in other countries/territories were less than 10 per day. Several effective measures including restricting travel from China, controlling the distribution of masks, extensive investigation of COVID-19 spread, and at once daily press conference by government to inform and educate people were aggressively conducted in Taiwan. This is probably the reason why there was only 39 cases (as of February 29, 2020) with a DCI of 1 case per day in Taiwan, which was much lower than that of nearby countries, such as Republic of Korea and Japan. Additionally, the incidence and mortality were correlated with DCI. However, further study and continued monitoring are needed to better understand the underlying mechanism of COVID-19.

3

Standard dosing of antimicrobials derived from product information (PI) is considered to have limited application in critically ill patients given the pharmacokinetic (PK) and pharmacodynamic (PD) changes often seen in these patients relative to other groups in the hospital. Dosing nomograms that account for the altered needs of critically ill patients are needed to minimise the likelihood of antimicrobial underdosing (risks treatment failure) and overdosing (risks toxicity) in these patients. The aim of this paper is to present a pragmatic, evidence-based, adultdosing nomogram for a selection of antimicrobials frequently prescribed to treat infections in critically ill patients.