Background: Human brucellosis is an infectious zoonotic disease caused by Brucella spp. It is one of the most public health problems that remains largely neglected in developing counties, including Saudi Arabia. Brucellosis is particularly prevalent among rural people who have constant contact with livestock. Methods: A cross-sectional sero-epidemiological study conducted in Aseer Central Hospital, South Saudi Arabia, between 2014 and 2018 among 7567 patients. Serum samples were analyzed for Brucella antibodies using slide agglutination test. Serology results and patient's demographic data were analyzed by GraphPad Prism. Results were presented as mean ± SEM and differences between two groups were assessed by t-test and p < 0.05 was considered significant. Results: The prevalence of brucellosis among the admitted suspected 7567 cases was 12.8% (10.4-15.7%; CI 95%). The highest prevalence rate was detected during 2015, the rate decreased to the lowest level during the last three years (p < 0.05). Higher rate of brucellosis was observed among males than females (p < 0.05) and most cases were reported during summer season (p < 0.05). The highest prevalence rate was observed in age group 21-40 year old (40.5%) followed by 41-60 years (27.7%). The lowest prevalence rate was noticed in old and young children (15 and 3%, respectively). Cross-transmission of brucellosis was seen within family (1%) and high titers (> 1280) was noticed in 22% of the hospitalized patients. The major symptoms were fatigue, hyperhidrosis, fever and joint pain. Conclusion: Our findings showed a high prevalence of human brucellosis among suspected patients in Aseer region. This indicates that clinical suspicion is a valid criterion and the endemic nature of the disease. The disease status requires early laboratory detection and confirmation to start prompt treatment to decrease patients suffering.

Staphylococcus aureus causes the majority of skin and soft tissue infections. Half of patients treated for primary skin infections suffer recurrences within 6 months despite appropriate antibiotic sensitivities and infection control measures. We investigated whether S. aureus internalized by human skin keratinocytes are effectively eradicated by standard anti-staphylococcal antibiotics. S. aureus, but not S. epidermidis, were internalized and survive within keratinocytes without inducing cytotoxicity or releasing the IL-33 danger signal. Except for rifampicin, anti-staphylococcal antibiotics in regular clinical use, including flucloxacillin, teicoplanin, clindamycin, and linezolid, did not kill internalized S. aureus, even at 20-fold their standard minimal inhibitory concentration. We conclude that internalization of S. aureus by human skin keratinocytes allows the bacteria to evade killing by most anti-staphylococcal antibiotics. Antimicrobial strategies, including antibiotic combinations better able to penetrate into mammalian cells are required if intracellular S. aureus are to be effectively eradicated and recurrent infections prevented.

Background: S. aureus is the dominant infective trigger of atopic dermatitis (AD). How this bacterium drives type 2 allergic pathology in the absence of infection in AD patients is unclear.Objective: To identify the S. aureus-derived virulence factor(s) that initiates the cutaneous type 2-promoting immune response responsible for AD.Methods: In vitro human keratinocyte cell culture, ex vivo human skin organ explants and the eczema prone Nc/Tnd mouse were used as model systems to assess type-2 promoting immune responses to S. aureus. Identification of the bioactive factor was accomplished using Fast Protein Liquid Chromatography and mass spectrometry. Bioactivity was confirmed by cloning and expression in an E. coli vector system, and S. aureus Sbi mutant strains confirming loss of activity.Results: S. aureus was unique amongst staphylococcal species in its ability to induce the rapid release of constitutive IL-33 from human keratinocytes independent of the toll-like receptor pathway. Using the eczema-prone NC/Tnd mouse model, we showed that IL-33 was essential in inducing the immune response to S. aureus in vivo. By fractionation and candidate testing, we identified the Second Immunoglobulin-Binding Protein (Sbi) as the predominant staphylococcus-derived virulence factor that directly drives IL-33 release from human keratinocytes. Immunohistology of skin demonstrated that corneodesmosin, a component of corneodesmosomes that form key intercellular adhesive structures in the stratum corneum, was disrupted resulting in reduction of skin barrier function.Conclusion: S. aureus-derived Sbi is a unique type 2-promoting virulence factor capable of initiating the type-2 promoting cytokine activity underlying AD.

The interaction of mesenchymal stromal cells (MSCs) with paracrine signals and immunological cells, and their responses and regenerative commitment thereafter, is understudied. In the current investigation, we compared MSCs from the umbilical cord blood (UCB), dental pulp (DP), and liposuction material (LS) on their ability to respond to activated neutrophils. Cytokine profiling (interleukin‐1α [IL‐1α], IL‐2, IL‐4, IL‐6, IL‐8, tumor necrosis factor‐α [TNF‐α], interferon‐γ [IFN‐γ], transforming growth factor‐β [TGF‐β]), cellular proliferation and osteogenic differentiation patterns were assessed. The results showed largely comparable cytokine profiles with higher TNF‐α and IFN‐γ levels in LSMSCs owing to their mature cellular phenotype. The viability and proliferation between LS/DP/UCB MSCs were comparable in the coculture group, while direct activation of MSCs with lipopolysaccharide (LPS) showed comparable proliferation with significant cell death in UCB MSCs and slightly higher cell death in the other two types of MSC. Furthermore, when MSCs post‐neutrophil exposure were induced for osteogenic differentiation, though all the MSCs devoid of the sources differentiated, we observed rapid and significant turnover of DPMSCs positive of osteogenic markers rather than LS and UCB MSCs. We further observed a significant turnover of IL‐1α and TGF‐β at mRNA and cytokine levels, indicating the commitment of MSCs to differentiate through interacting with immunological cells or bacterial products like neutrophils or LPS, respectively. Taken together, these results suggest that MSCs have more or less similar cytokine responses devoid of their anatomical niche. They readily switch over from the cytokine responsive cell phenotype at the immunological microenvironment to differentiate and regenerate tissue in response to cellular signals.

Mycobacterium tuberculosis (Mtb) is a deadly tuberculosis (TB)-causing pathogen. The proteasome is vital to the survival of Mtb and is therefore validated as a potential target for anti-TB therapy. Mtb resistance to existing antibacterial agents has enhanced drastically, becoming a worldwide health issue. Therefore, new potential therapeutic agents need to be developed that can overcome the complications of TB. With this purpose, in the present study, 224,205 natural compounds from the ZINC database have been screened against the catalytic site of Mtb proteasome by the computational approach. The best scoring hits, ZINC3875469, ZINC4076131, and ZINC1883067, demonstrated robust interaction with Mtb proteasome with binding energy values of −7.19, −7.95, and −7.21 kcal/mol for the monomer (K-chain) and −8.05, −9.10, and −7.07 kcal/mol for the dimer (both K and L chains) of the beta subunit, which is relatively higher than that of reference compound HT1171 (−5.83 kcal/mol (monomer) and −5.97 kcal/mol (dimer)). In-depth molecular docking of top-scoring compounds with Mtb proteasome reveals that amino acid residues Thr1, Arg19, Ser20, Thr21, Gln22, Gly23, Asn24, Lys33, Gly47, Asp124, Ala126, Trp129, and Ala180 are crucial in binding. Furthermore, a molecular dynamics study showed steady-state interaction of hit compounds with Mtb proteasome. Computational prediction of physicochemical property assessment showed that these hits are non-toxic and possess good drug-likeness properties. This study proposed that these compounds could be utilized as potential inhibitors of Mtb proteasome to combat TB infection. However, there is a need for further bench work experiments for their validation as inhibitors of Mtb proteasome.

Background: Healthcare-associated infections (HAIs) are a global public health problem. For the fulfillment of Saudi Arabia's Vision 2030, the promotion of preventive care medicine through HAI management is a crucial issue. This study explores the perspectives of Saudi tertiary healthcare workers (HCWs) on HAIs and infection control measures. Methods: Quantitative data were assessed to determine HCWs' knowledge of HAI and their attitudes towards and practice of infection control measures. Semi-structured interviews were used to collect qualitative data from 40 doctors and nurses. The interviews were audio-recorded and transcribed verbatim. Further, routine sterile procedures in the wards and intensive care units were video recorded, and the footage was discussed by the infection control team and the personnel involved in the videos. This discussion was videographed and transcribed. Both interview data and reflective discussion of the video were analysed using thematic analysis. The quantitative data were analysed using the Kruskal-Wallis test and logistic regression analysis. Results: Kruskal-Wallis test revealed no difference in mean knowledge, attitude, or practice scores between nurses/ doctors or the genders. There was a significant difference in knowledge score and practice scores between the Intensive care unit & the Paediatric ward /infection control department with the maximum scores in knowledge and practice among participants from the intensive care unit. Logistic regression analysis for dependent variables (knowledge and attitude) and independent variables like age, gender, designation, and departments was not significant. The qualitative data yielded four themes: knowledge of HAI and infection control, infection control measures in practice, a shortfall in infection control measures and HAI, and required implementation. Video-reflexive ethnography (VRE) revealed lapses in handwashing practice and proper usage of personal protective equipment (PPE), especially surgical masks.

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Multidrug-resistant (MDR) Acinetobacter species are opportunistic pathogens that are clinically important, which causes severe infection during a prolonged stay in an Intensive Care Unit (ICU) of the hospital. In the present study, we screened clinical isolates of Acinetobacter species for its MDR nature from the ICU of a tertiary care centre at Abha, Saudi Arabia during the period of 2013-2017. Confirmed MDR Acinetobacter species clinical isolates were challenged against ethanolic extracts from mango kernel (Mangifera Indica L.) by classical disc diffusion method. In total, we characterized 124 MDR Acinetobacter isolates, out of which 62 (50%) were Acinetobacter baumannii (MDR-AB), 41 (33.1%) were Acinetobacter baumannii complex (MDR-ABC), 15 (12.1%) were Acinetobacter baumannii-haemolyticus (MDR-ABH), 3 (2.4%) were Acinetobacter haemolyticus (MDR-AH) and 3 (2.4%) were Acinetobacter iwoffii (MDR-AI). We observed that MDR-AB isolates were inhibited by ethanolic extract of M. indica with minimum inhibition concentration (MIC) of 0.25 mg/ml. Concentrations of 50 mg/mL, 5 mg/mL and 0.5 mg/mL exhibited average inhibition zones of 18.74±0.09, 15.51±0.08 and 9.74±0.06 mm respectively showing a concentration dependent antagonisms (R2= 0.947). The results of M. indica were comparable to Colistin inhibition zone of 14.98±0.72 mm with 50 mg/mL and 5 mg/mL exceeded those of the positive control (p= 0.6721 and 0.1045, respectively). However, Colistin showed minor increase over M. indica at the concentration 0.5-mg/ mL (p= 0.5384). More specifically, MDR-AB strains have shown a substantial susceptibility to mango kernel extract (0.25 mg/mL) with antagonism similar to that of Colistin. Thus, the study shows that the extracts of mango kernel as a potential drug target and could be potentially used as an adjunct treatment along with the standard agents to treat Acinetobacter infections.