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Effective ventilation plays a crucial role in reducing the risk of infection by airborne contaminants. This study was conducted in a hospital ward of specific dimensions (41.58 m3) equipped with two respiratory thermal manikins: a healthcare worker and an infected patient. Three ventilation strategies were employed in the ventilation system: supply and exhaust air through upper grilles, upper and lower grilles, and swirl diffusers with lower grilles. The air flow rate of the ventilation system was maintained constant at 200 m3/h. The airflow was distributed 50–50 % by a combination of a personalised ventilation system and personalised exhaust system. The effectiveness of a ventilation system and its combination with a personalised exhaust system was investigated using aerosol and tracer gas techniques. The efficacy of contaminant removal was evaluated in both the patient and healthcare inhaled volume. Determination of the clean air flow rate of the three ventilation system strategies at inhaled volume was carried out. Also, the exposure of healthcare worker to the contaminants exhaled by infected patient in the microenvironment formed by both was analysed. Experimental findings revealed that CO2 showed a higher ventilation efficiency compared to particles, independently of the ventilation strategy used. The highest clean air flow rate values were detected in the inhaled volume of patient infected. On the other hand, the highest particle removal efficiency was observed in swirl diffusers with lower grilles, which combined the ventilation system with the PES. This strategy also showed the lowest exposure values in the microenvironment.

الملخص: أهداف البحث: سلطت الدراسة الضوء على انتشار أنواع العصيات (بما في ذلك المقاومة للأدوية) في بيئات المستشفيات العامة وتدعو إلى تصميم استراتيجيات مثالية للحد من انتشارها وهو أمر بالغ الأهمية في جميع أنظمة الرعاية الصحية مثل الرعاية لعدد متزايد من المرضى الذين يعانون من ضعف المناعة. طريقة البحث: تم جمع ما مجموعه 528 عينة مسحة من بيئة المستشفيات السعودية المختلفة. تم جمع عينات المسحات عن طريق مسح ما يقرب من 5 سم مربع من السطح في كل موقع باستخدام مسحات قطنية مبللة مسبقا مع محلول معادل بسعة 1 مل (ديفكو ، الولايات المتحدة الأمريكية). تم نقل المسحات في صناديق تبريد مع أكياس ثلج في غضون ساعتين من التجميع. تم إجراء العزل والتعريف وفقا لطرق التوصيف البكتريولوجية التقليدية ، والسمية الآلية ، والجزيئية. تم إجراء تصنيف المضادات الحيوية ضد مجموعات مختلفة من العوامل المضادة للميكروبات. النتائج: أما الأنواع المعزولة فكانت العصوية الشمعية (46,6%) تليها العصوية الرقيقة (38,1%) بينما كانت العصوية القزمة الأقل انتشارا (1.1٪). غالبية عزلات العصيات (25,6%) كانت من قسم الطب الباطني يليه قسم الطوارئ (18.8٪) بينما أظهرت غرف العمليات أقل معدل انتشار (4.5٪). أظهر اختبار الحساسية لمضادات الميكروبات مقاومة عالية لعزلات العصيات للبيتا-لاكتام و تتراسيكلين هيدروكلوريد. العزلات المقاومة للأدوية المتعددة والتي كانت مقاومة ثلاثة أو أكثر من المضادات الحيوية (21.6٪). أظهر تصنيف المضادات الحيوية لـ 176 عزلة وجود 45 نوعا من المضادات وأكثرها شيوعا كانت من النمط 31، والتي اشتملت على 32 عزلة (18.2٪) مقاومة للبنسلين والسيفوكسيتين. الاستنتاجات: كشفت هذه الدراسة عن الانتشار الواسع لأنواع العصيات في بيئات المستشفيات التي في الدراسة ذات المقاومة العالية لمضادات بيتا-لاكتام والتتراسيكلين. أظهر التحليل الجزيئي وجود تنوع وراثي بين عزلات العصيات المدروسة. وبالتالي، فإن مراقبة بيئة المستشفى هي أداة مهمة في الوقاية من العدوى المرتبطة بالمستشفيات بأنواع العصيات. Abstract: Objective: This study highlighted the dissemination of Bacillus species (including drug-resistant species) in public hospital environments and calls for the design of optimal strategies to curb their spread. This a critical consideration for all health care systems such as caring for the increasing number of immune-compromised patient. Methods: A total of 528 swab samples were collected from the environments of different Saudi hospitals. Swab samples were collected by swabbing approximately 5 cm2 of different surfaces at each site using pre-moisturized cotton swabs with 1 mL of neutralizing buffer. The swabs were transported in cool boxes with ice packs within 2 h of collection. Isolation and identification were performed according to conventional bacteriological, semi-automated and molecular characterization methods. Antibiogram typing was carried against different groups of antimicrobial agents. Results: The most prevalent of the isolated Bacillus species were Bacillus cereus (46.6%) followed by Bacillus subtilis (38.1%); the least prevalent was Bacillus pumilus (1.1%). Most Bacillus isolates (25.6%) were isolated from the Department of Internal Medicine followed by the Emergency Department (18.8%), while the operating rooms had the lowest prevalence (4.5%). Antimicrobial susceptibility testing revealed high levels of resistance in Bacillus isolates to β-lactams and tetracycline. Overall, 21.6% of isolates showed multi-drug resistance to three or more antibiotics (21.6%). Antibiogram typing of the 176 isolates revealed 45 antibiotypes; the most common was antibiotype 31, which included 32 isolates (18.2%); this particular antibiotype was resistant to both penicillin and cefoxitin. Conclusions: Analyses identified the high dissemination of Bacillus species in several hospital environments with high resistance to β-lactams and tetracycline antibiotics. Molecular analysis also revealed the existence of genetic diversity among the Bacillus isolates investigated. Thus, monitoring the hospital environment is an important tool in the prevention of hospital-associated infection by Bacillus species.

Extended spectrum β-lactamase producing Escherichia coli (ESBL E. coli) is a primary concern for hospital and community healthcare settings, often linked to an increased incidence of nosocomial infections. This study investigated the characteristics of ESBL E. coli isolated from hospital environments and clinical samples. In total, 117 ESBL E. coli isolates were obtained. The isolates were subjected to molecular analysis for the presence of resistance and virulence genes, antibiotic susceptibility testing, quantitative adherence assay, ERIC-PCR for phylogenetic analysis and whole genome sequencing of four highly drug resistant isolates. Out of the 117 isolates, 68.4% were positive for blaCTX-M, 39.3% for blaTEM, 30.8% for blaNDM-1, 13.7% for blaOXA and 1.7% for blaSHV gene. Upon screening for diarrheagenic genes, no isolates were found to harbour any of the tested genes. In the case of extraintestinal pathogenic E. coli (ExPEC) virulence factors, 7.6%, 11%, 5.9%, 4.3% and 21.2% of isolates harbored the focG, kpsMII, sfaS, afa and iutA genes, respectively. At a temperature of 25°C, 14.5% of isolates exhibited strong biofilm formation with 21.4% and 28.2% exhibiting moderate and weak biofilm formation respectively, whereas 35.9% were non-biofilm formers. On the other hand at 37°C, 2.6% of isolates showed strong biofilm formation with 3.4% and 31.6% showing moderate and weak biofilm formation respectively, whereas, 62.4% were non-biofilm formers. Regarding antibiotic susceptibility testing, all isolates were found to be multidrug-resistant (MDR), with 30 isolates being highly drug resistant. ERIC-PCR resulted in 12 clusters, with cluster E−10 containing the maximum number of isolates. Hierarchical clustering and correlation analysis revealed associations between environmental and clinical isolates, indicating likely transmission and dissemination from the hospital environment to the patients. The whole genome sequencing of four highly drug resistant ExPEC isolates showed the presence of various antimicrobial resistance genes, virulence factors and mobile genetic elements, with isolates harbouring the plasmid incompatibility group IncF (FII, FIB, FIA). The sequenced isolates were identified as human pathogens with a 93.3% average score. This study suggests that ESBL producing E. coli are prevalent in the healthcare settings of Bangladesh, acting as a potential reservoir for AMR bacteria. This information may have a profound effect on treatment, and improvements in public healthcare policies are a necessity to combat the increased incidences of hospital-acquired infections in the country.

Background: The adenosine triphosphate (ATP) assay is widely used for simple and rapid evaluation of the cleanliness of environmental surfaces. However, there remain concerns regarding the reliability of the ATP assay in hospital settings. This study aimed to assess whether the ATP assay could detect inadequate cleaning within hospital environments as well as monitor the effectiveness of routine cleaning., Methods: The cleanliness of seven types of high-touch surfaces in operating rooms that were routinely cleaned was evaluated by testing the ATP assay and aerobic colony counts (ACC). For pressure redistribution mattresses (Soft-nurse®) that were found to be particularly at risk of infection, cleaning methods were improved, and the effectiveness of these improvements was monitored using the same two methods., Results: The ATP assay quantitatively detected contamination on seven high-touch surfaces but showed no correlation with ACC. However, a significant positive correlation between luminescence and ACC was found on one specific surface, allowing for determining a theoretical cutoff value. Additionally, the ATP assay effectively identified the risk of future infection, which the ACC test could not assess., Conclusions: The ATP assay can monitor the effectiveness of routine cleaning by setting a theoretical cutoff value for each subject. The method provides quantitative and meaningful values when used with an understanding of its limitations., (Copyright © 2023 Australasian College for Infection Prevention and Control. Published by Elsevier B.V. All rights reserved.)

Antimicrobial resistance has been recognized as an important emerging environmental pollutant. 'Last-resort' antibiotics including tigecycline, polymyxin E, daptomycin, vancomycin and linezolid are the 'last line of defence' for antibiotic resistant pathogen infections. Therefore, the presence of 'last-resort' antibiotic resistant pathogens in hospital environments and the nosocomial transmission of 'last-resort' antibiotic resistance poses a grave threat to the well-being of patients. In this work, the extent of resistance to 'last-resort' antibiotics in culturable pathogens in hospital wastewater was investigated. Resistance to 'last-resort' antibiotics were quantified for 1384 culturable Enterobacteriaceae, Enterococcus, Staphylococcus, and Pseudomonas strains. With these investigations, several significant findings were made: (1) a very high level of resistance to 'last-resort' antibiotics was found; (2) multiple resistance to antibiotics, including 'last-resort' antibiotics, was prevalent; (3) a high level of 'last-resort' antibiotic resistance phenotype-genotype inconsistency was found, suggesting knowledge gap for resistance mechanisms; 4) tet(X4)-containing tigecycline-resistant Gram-positive pathogens were found for the first time; 5) wastewater treatment processes are effective in preventing the release of 'last-resort' antibiotic resistant pathogens to the environment. This investigation reveals the severe situation on 'last-resort' resistance in the hospital environment, and implies high risk for nosocomial transmission of 'last-resort' antibiotic resistant pathogens., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Healthcare-associated items are a common source of acquired infections, and hospital-acquired infections cause significant mortality and morbidity worldwide. Acinetobacter baumannii is the most prevalent infection-causing organism in the hospital environment. Hospital articles and objects are the main sources of infection with the ability to transmit some of the pathogenic microorganisms such as A. baumannii , which is considered a serious problem in therapeutic treatments. In the current study, we isolated A. baumannii from hospital sources and evaluated its antibiotic resistance, virulence factors and resistance gene determinants. The isolates were identified phenotypically as well as genotypically using PCR. In addition, their capability for biofilm formation and ten other virulence factors were measured. Of 112 samples, 21 showed growth of the target organism. Apart from A. baumannii , isolates of Candida albicans , Staphylococcus sp., Pseudomonas aeruginosa , Escherichia coli and Klebsiella pneumoniae were also grown. Antibiotic susceptibility test results considered all the A. baumannii to be multidrug-resistant isolates with the highest resistance being 100% to gentamycin, ciprofloxacin; the most effective antibiotics with 100% susceptibility was colistin and tigecycline. All A. baumannii isolates had MIC for ceftriaxone >32 mg/L. All A. baumannii isolates from the hospital environment showed multidrug resistance and had many virulence factors. They have long-term resistance to dry conditions and cause a serious public health issue.