The Prevalence and Antimicrobial Susceptibility of Methicillin-Resistant Staphylococcus aureus Before and After the COVID-19 Pandemic in a Tertiary Saudi Hospital.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) has become a major public health problem all over the world. After the 2019 coronavirus illness (COVID-19), the pandemic may have influenced research priorities and resource allocation, potentially affecting the ability to monitor MRSA trends. AIMS: The study aimed to evaluate the prevalence of S. aureus, including MRSA infections, and their antimicrobial susceptibilities over the years 2019 and 2020 in a tertiary hospital in Makkah City, KSA. METHODOLOGY: A total of 2128 and 1515 laboratory (lab) samples were collected during the years 2019 and 2020, respectively. From these samples, the prevalence of S. aureus, including MRSA, and their antibiotic susceptibility were identified using standard, automated, and molecular microbiological methods. RESULTS: The present study shows that the lab prevalence of all S. aureus during 2019 was found to be 35.5%, of which MRSA was 44.8%. During 2020, the frequency of S. aureus strains was 16%, of which MRSA was 41.2%. The most common MRSA isolated during both years were colonizing pus swabs and urine samples. The results showed that MRSA susceptibility against antimicrobial agents in 2019 was as follows: vancomycin (100%), linezolid (100%), trimethoprim-sulfamethoxazole (88%), and doxycycline (34.2%). The MRSA strains isolated during 2020 were as follows: vancomycin (100%), linezolid (96%), trimethoprim-sulfamethoxazole (100%), and doxycycline (24.3%). There was no significant difference in the incidence and antimicrobial resistance rates of MRSA over the two years. CONCLUSION: It was concluded that the prevalence rates of MRSA have not increased in 2020 when compared to 2019. Vancomycin, linezolid, trimethoprim-sulfamethoxazole, and doxycycline remain susceptible to the positive collected MRSA strains. There was no significant difference between the prevalence and antimicrobial resistance rates of MRSA between 2019 and 2020. Continued research efforts are needed to address this persistent public health threat. Strategies to control the spread of MRSA should include early detection of MRSA and surveillance, even during pandemics.

Characterization of aminoglycoside resistance genes in multidrug-resistant Klebsiella pneumoniae collected from tertiary hospitals during the COVID-19 pandemic.

Since the peak of the coronavirus disease 2019 (COVID-19) pandemic, concerns around multidrug-resistant (MDR) bacterial pathogens have increased. This study aimed to characterize aminoglycoside resistance genes in MDR Klebsiella pneumoniae (K. pneumoniae) collected during the COVID-19 pandemic. A total of 220 clinical isolates of gram-negative bacteria were collected from tertiary hospitals in Makkah, Saudi Arabia, between April 2020 and January 2021. The prevalence of K. pneumoniae was 40.5%; of the 89 K. pneumoniae isolates, MDR patterns were found among 51 (57.3%) strains. The MDR isolates showed elevated resistance rates to aminoglycoside agents, including amikacin (100%), gentamicin (98%), and tobramycin (98%). PCR assays detected one or more aminoglycoside genes in 42 (82.3%) MDR K. pneumoniae strains. The rmtD gene was the most predominant gene (66.7%; 34/51), followed by aac(6')-Ib and aph(3')-Ia (45.1%; 23/51). The aac(3)-II gene was the least frequent gene (7.8%; 4/51) produced by our isolates. The rmtC gene was not detected in the studied isolates. Our findings indicated a high risk of MDR bacterial infections through the COVID-19 outbreak. Therefore, there is a need for continuous implementation of effective infection prevention control (IPC) measures to monitor the occurrence of MDR pathogens and the emergence of MDR bacterial infections through the COVID-19 outbreak.

Evaluation of Drinking Water Quality From Water Coolers in Makkah, Saudi Arabia.

The quality of drinking water is an important health issue in crowded cities, so that an adequate drinking water with good quality must be provided, hence over hundreds of water coolers are distributed in Makkah city to cope with the increasing demand for drinking water. The present study aimed to determine the chemical and microbial quality of drinking water from coolers in Makkah city. Sixty-three samples from randomly selected water coolers were tested for chemical and bacteriological quality. For all samples, the mean value of physiochemical tests of pH (7.12), TDS (152.7 ppm), turbidity (2.56 NTU), free chlorine (0.312 ppm), fluoride (0.112 ppm), chloride (25.7 ppm), bromide (0.123 ppm), nitrate (0.616 ppm), sulfate (8.36 ppm), lithium (0.134 ppm), sodium (17.6 ppm), potassium (1.42 ppm), magnesium (1.95 ppm), calcium (19.2 ppm), chromium (0.025 ppm), cadmium (0.0026 ppm), and lead (0.0244 ppm) did not exceed the reference values of the drinking water regulations. The total coliform count was detected in 3.2% of the water samples. For total coliform count, the MPN in the majority of water samples (96.8%) was excellent while for E. coli count, the MPN in all water samples (100%) was excellent. Bacteriological quality has shown that no Pseudomonas, Salmonellae, or Legionellae species contamination detected. It was concluded that, the drinking waters in coolers in Makkah city were complied with international standards and within the acceptable limit. It is worth to continue periodic inspection and maintenance for the drinking water coolers during mass gatherings.

Molecular Epidemiology of Carbapenem-Resistant K. pneumoniae Clinical Isolates from the Adult Patients with Comorbidities in a Tertiary Hospital, Southern Saudi Arabia.

Hospitalized patients are likely to have chronic illnesses and are at an increased risk of mortality due to infection caused by MDR bacteria. We aimed to identify carbapenem-resistant genes carrying Klebsiella pneumoniae (K. pneumoniae) isolates and their risk factors recovered from adult patients with comorbidities. A cross-sectional study was carried out between April 2021 and December 2021 at King Abdullah Hospital (KAH) in Bisha province, Saudi Arabia. Seventy-one multi-drug resistant K. pneumoniae recovered from clinical samples and screened for carbapenemase genes of blaOXA-48-like, blaNDM-1, blaKPC, blaVIM, and blaIMP. Of 71 MDR K. pneumoniae examined, 47 (66.2%) isolates harbored various carbapenemase genes. The most prevalent single resistance gene was blaOXA-48-like (62.5%; n = 25), and 33.3% of them were recovered from sputum isolates. The blaNDM-1 gene was detected in 12 (30.0%) isolates, and eight of them were recovered from urine (n = 4) and blood (n = 4). Two (5.0%) single blaKPC genes were recovered from the sputum (n = 1) and blood (n = 1) isolates. In contrast, no blaIMP- and blaVIM-carrying isolates were detected. The co-existence of two resistance genes between blaOXA-48-like and blaNDM-1 was found in six strains, whereas only one strain was found to be produced in the three genes of blaNDM-1, blaKPC, and blaOXA-48-like. There were statistically significant associations between the presence of carbapenem-gene-carrying K. pneumoniae and patients' gender (χ2(1) = 5.94, p = 0.015), intensive care unit admission (χ2(1) = 7.649, p = 0.002), and chronic obstructive pulmonary disease (χ2(1) = 4.851, p = 0.028). The study highlighted the existence of carbapenemase-producing K. pneumoniae, particularly blaOXA-48-like and blaNDM-1, in patients with comorbidities. Our findings emphasize the importance of the molecular characterization of resistance-determinant-carrying bacterial pathogens as a part of infection control and prevention in hospital settings.

Evaluation of the antibacterial activities of face masks coated with titanium dioxide nanoparticles.

To control infectious diseases, various applications of nanotechnology have been used to enhance the self-cleaning and antibacterial properties of materials. This study aimed to evaluate the antibacterial properties of face masks coated with TiO2 nanoparticles. The antibacterial efficacies of cloth face masks coated with TiO2 were measured by inoculating them in bacterial suspensions (105 CFUs from both E. coli and S. aureus). The results showed that TiO2 nanoparticle solutions (at 2%) reduced the starting inoculum of 105 CFUs (5 log cfu/cm2) of E. coli and S. aureus to 1.3 and 1.68 log, respectively, with antibacterial activities of 3.7 and 3.34 log, respectively. Furthermore, at a 1% concentration, the antibacterial activities against E. coli and S. aureus were 2.1 and 2.01 log, respectively, while at a low concentration (0.5%), the antibacterial activities against E. coli and S. aureus were 1.8 and 1.72 log, respectively. The CFUs in all the experimental groups were significantly lower than those in the control group (saline). In conclusion, TiO2 nanoparticle solutions with a high concentration (2%) demonstrated a strong antibacterial effect on E. coli and S. aureus, and the difference was statistically significant, while a significant antibacterial activity was demonstrated with lower concentration (0.5% and 1%) nanoparticle solutions of TiO2 after 18 h. There was a statistically significant difference regarding colony reduction between E. coli and S. aureus even at 3 h. The antibacterial activities of TiO2 in face masks could be promising for reducing the risk of bacterial infections.

Detection of Antibiotic Resistance Genes in Pseudomonas aeruginosa by Whole Genome Sequencing.

Background: Multidrug-resistant Pseudomonas aeruginosa has become a hazard to public health, making medical treatment challenging and ineffective. Whole-genome sequencing for antibiotic susceptibility testing offers a powerful replacement for conventional microbiological methods. Objective: The present study evaluated the presence of antibiotic resistance genes in selected clinical strains of P. aeruginosa using whole-genome sequencing for antibiotic susceptibility testing. Results: Whole-genome sequencing of P. aeruginosa susceptible to common antibiotics showed the presence of 4 antibiotic resistance gene types, fosA, catB7, blaPAO, and blaOXA-50. Whole genome sequencing of resistant or multidrug-resistant P. aeruginosa showed the presence of multiple ARGs, such as sul1, aac(3)-Ic, blaPAO, blaGES-1, blaGES-5 aph (3')-XV, blaOXA-50, aacA4, catB7, aph(3')-IIb, aadA6, fosA, tet(G), cmlA1, aac(6')Ib-cr, and rmtF. Conclusion: The acquisition of antibiotic resistance genes was found to depend on the resistance of Pseudomonas to antibiotics. The strain with the highest resistance to antibiotics had the highest acquisition of antibiotic resistance genes. MDR-P. aeruginosa produces antibiotic resistance genes against aminoglycoside, ß-lactam, fluoroquinolones, sulfonamides, phenicol, and fosfomycin antibiotics.

Detection of Helicobacter pylori in Gastric Biopsies Among Sudanese Patients with Confirmed Gastric Disorders Using Three Diagnostic Methods.

BACKGROUND: Helicobacter pylori (H. pylori) infection represents one of the most common chronic bacterial infections in developing countries. However, in Sudan, the infection is not well diagnosed with standard laboratory methods in many parts of the country. This study aimed to detect H. pylori in gastric biopsies of patients with gastric disorders, using three diagnostic methods. MATERIALS AND METHODS: A cross-sectional study was conducted among 100 patients in Gezira state, central Sudan. Giemsa stain for histopathological examination (HPE), rapid urease test (RUT), and polymerase chain reaction (PCR) techniques were performed to detect H. pylori from the gastric biopsy samples as per standard assays. RESULTS: Most of the patients were males (66%), from rural areas (72%) and in the age group 31 to 50 years. H. pylori were identified in 85% of the samples by at least one of the three tests. The highest positivity was detected by HPE (83%), followed by PCR (67%) and RUT (63%), while 59% were positive by the three diagnostic methods. PCR showed higher sensitivity (80.72% vs. 73.49%) and specificity (100% vs. 88.24%) than RUT. Positive predictive values were reported as 100% for PCR and 96.83% for RUT. Considering PCR as a gold standard method, HPE revealed higher sensitivity (100%) than RUT (88.06%). On the contrary, RUT showed higher specificity (87.88%) than PCR (51.52%). There were no significant associations between H. pylori infection patients' gender (p = 0.747). Loss of weight (p = 0.007) and nausea (p = 0.032) were significantly associated with H. pylori infection. CONCLUSIONS: There was a high prevalence of H. pylori infection in central Sudan. This highlights the need to analyze epidemiological status, virulence factors, and strain characteristics to control disease transmission. PCR is a reliable and valuable technique in detecting H. pylori infection from gastric biopsy samples.

Assessment of supplied water quality during mass gatherings in arid environments.

Mass gathering events commonly encounter environmental challenges that necessitate assurance of water quality and food security. The current outbreak of the coronavirus disease 2019 (COVID-19) call for maintaining safe drinking water supply and providing assessment tools of drinking water quality to avoid contamination in water sources or distribution networks. Arid environmental conditions also add more stress on supplied water to mass gathering events. Herein, we assess the quality of the water supply (desalinated 95% and groundwater 5%) in Makkah city, Saudi Arabia during a mass gathering event in 2019 (9.6 million people) for religious purposes. Fifty five samples were randomly collected from nine different districts of Makkah city, analyzed for TDS, turbidity, pH, EC, free Cl2, Al, Cd, Pb, Cr, F, major ions, coliform and E.coli bacteria and were finally used to estimate the water quality index (WQI). Major ions, trace elements and heavy metals analyses show values below permissible limits in most of the samples, while a few samples show slightly higher values. No bacterial count found in any sample. WQI values of all fifty-five samples were below 50 and were identified as "excellent water". The WQI variations could be attributed to the distribution network conditions rather than a direct impact of adding groundwater with uncontrolled chemical composition. The use of WQI to report the quality of water during mass gathering events to governmental authorities has been proved to be beneficial and should be applied for further mass gathering events worldwide.

Geo-environmental approach to assess heavy metals around auto-body refinishing shops using bio-monitors.

The vehicular industry is looking for continuous challenges to develop the sustainability of its manufacturing, maintenance processes, and vehicle emissions due to marketability, environmental, economic, and policy concerns. The present study focuses on the impact of these processes on the environment. In Pakistan, most of the auto-body refinishing processes are carried out in an open atmosphere. The shades of Azadirachta indica (Neem Tree) are generally used for the outdoor practice of scrapping, grinding, and painting in auto-body refinishing shops of Pakistan. Azadirachta indica leaves were selected as bio-indicator. For the present work, 26 affected sites and 10 control sites were selected from Karachi city, which is the financial hub and biggest city of Pakistan. Concentrations of different metals (Fe, Co, Cd, Cr, Cu, Mn, Mo, Ni, Pb, and Zn) were determined by atomic absorption spectrophotometer. A geographic information system (GIS) is used to present the variation in concentrations within Karachi city. The only positive correlation was observed in Pb and Mn (0.750). Principal component analysis (PCA) is applied to identify the anthropogenic effect between auto-body refinishing areas and control areas. Almost all analyzed metals show higher concentration at affected sites but Pb (87.14 mg/kg), Mn (46.47 mg/kg) and Fe (146.95 mg/kg) were leading the values, as compared to their concentration at control sites, Pb (48.83 mg/kg), Mn (15.23 mg/kg) and Fe (43.07 mg/kg). All analyzed metals are frequently present in different color pigments, whereas Pb, Mn, and Fe may also come from other sources, like the anti-knocking agent, vehicular exhaust, and scraping of car surface.

An Epidemiological Study of COVID-19 Cases in Al-Leith, Saudi Arabia.

Background and objective Ever since the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first detected in December 2019, more than 0.550 million cases of coronavirus disease 2019 (COVID-19) have been reported in the kingdom of Saudi Arabia (KSA) and the number is on the rise. In this study, we aimed to perform an epidemiological analysis of COVID-19 cases in Al-Leith, KSA. Methods A community-based descriptive study was carried out to assess the epidemiology of COVID-19 in Al-Leith, KSA. The relevant data were collected using a questionnaire designed for this study, which included questions on basic information and characteristics in addition to data on COVID-19. Data were analyzed using the SPSS Statistics software (IBM, Armonk, NY). Results The significant findings were as follows: people aged between 26-40 years were more affected (55.7%) than other age groups, and more than half (74.1%) of COVID-19 patients were female; most of them were employed (85, 48,9%), and most of those got infected through direct contact (137, 78.7%) with other infected people. About 163 (93.7%) cases were asymptomatic, and 168 (96.6%) cases were notified to the health authorities. The findings also illustrated that 78 (44.8%) COVID-19 cases suffered from psychological impact due to infection; 83 (47.7%) cases had at least one case in the family before they became infected. The majority of cases (93.7%) suffered from symptomatic COVID-19. A considerable number of COVID-19 patients did not follow precautions before and after infection. Conclusions The study concluded that various age groups were susceptible to developing COVID-19, and direct contact was the main mode of transmission. Moreover, a considerable number of infected people did not adhere to precautionary measures.

Evaluation of Food Trucks' Hygiene During Mass Gathering Events.

During any event, food- and waterborne diseases represent a health risk, so food should be kept in a chilled state while being supplied in the trucks before distribution to consumers. The study aimed to evaluate temperature conditions, microbial contamination of food trucks, and their compliance to the basic local and international standards of food safety during a mass gathering event (pilgrimage). Fifty food trucks were evaluated for proper food storing and microbial contamination (load). A food truck inspection checklist was made to check if the trucks followed the standards of food safety and hygiene. The results showed that 90% of the trucks' refrigerators were between 3 and 5°C. The number of total mesophilic and psychrotrophic bacteria in the contact surfaces varied between 1.93-6.16 (mean 4.0433) and 0.08-4.50 (mean 3.3340) log CFU (colony-forming units)/100 cm2, respectively. The studied food trucks met the standards of food safety and hygiene with a low mean level (45.2%), which was seen in monitoring thermometers/cold chain loggers, proper record of activities, proper disposal of food product waste, and proper practice of handwashing techniques. There were significant associations (p-value < 0.05) found between temperature readings and mesophilic microbial load. Efforts should be increased to reduce food loss by continuous monitoring of these trucks during mass gathering events.

Advances in Heavy Metal Bioremediation: An Overview.

The pollution of toxic heavy metals is considered one of the most important environmental issues which has accelerated dramatically due to changing industrial activities. This review focuses on the most common methods, strategies, and biological approaches of heavy metal bioremediation. Also, it provides a general overview of the role of microorganisms in the bioremediation of heavy metals in polluted environments. Advanced methods of heavy metal remediation include physicochemical and biological methods; the latter can be further classified into in situ and ex situ bioremediation. The in situ process includes bioventing, biosparging, biostimulation, bioaugmentation, and phytoremediation. Ex situ bioremediation includes land farming, composting, biopiles, and bioreactors. Bioremediation uses naturally occurring microorganisms such as Pseudomonas, Sphingomonas, Rhodococcus, Alcaligenes, and Mycobacterium. Generally, bioremediation is of very less effort, less labor intensive, cheap, ecofriendly, sustainable, and relatively easy to implement. Most of the disadvantages of bioremediation relate to the slowness and time-consumption; furthermore, the products of biodegradation sometimes become more toxic than the original compound. The performance evaluation of bioremediation might be difficult as it has no acceptable endpoint. There is a need for further studies to develop bioremediation technologies in order to find more biological solutions for bioremediation of heavy metal contamination from different environmental systems.

Increasing frequency of Aminoglycoside-Resistant Klebsiella pneumoniae during the era of pandemic COVID-19.

The emergence of multidrug resistance to aminoglycosides in K. pneumoniae isolates is a growing concern, especially during pandemic Coronavirus disease 2019 (COVID-19). The study identifies antibiotic resistance in K. pneumoniae isolated from tertiary hospitals during pandemic COVID-19. Among 220 clinical isolates, the total rate of K. pneumoniae was found to be 89 (40.5%). Phenotyping results confirmed the resistance of aminoglycoside antibiotics in 51 (23.2%) of K. pneumoniae isolates. PCR results confirmed the existence of one or more aminoglycoside genes in 82.3% of the 51 isolates. The rmtD gene was the highest-detected gene (66.7%), followed by aac(6')-Ib (45.1%), aph(3')-Ia (45.1%), rmtB (29.4%), armA (21.6%), aac(3)-II (7.8%), and rmtA (3) (11.8%). Significantly, higher resistance strains showed a higher prevalence (61.5%) of aminoglycoside genes (p < 0.05). During COVID-19, there is a higher risk of acquiring MDR bacterial infections, so the monitoring of multidrug resistant bacteria must be continuously undertaken to implement effective measures in infection control and prevention.

Zinc oxide nanoparticles prevent multidrug resistant Staphylococcus-induced footpad dermatitis in broilers.

The current experiment was designed to evaluate the effects of dietary supplementations of zinc oxide nanoparticles (ZONPs) on some behavioural, performance, welfare and histopathological changes in broilers exposed to multidrug resistant Staphylococcus aureus (MRSA)-induced footpad dermatitis (FPD). Eighty-four male Indian River (IR) broilers were randomly allotted to six different dietary treatments as follows: C-ve, C+ve, 10, 20, 30 and 40 ppm ZONPs from 7 to 49d of age. At day 28, broilers (n = 70) were sub-cutaneously injected with 0.5 ml of saline containing 5.3 × 107 CFU/ml of S. aureus (MRSA) in each metatarsal foot pad. Control (non-infected) broilers were given 0.5 ml of saline (n = 14). Results clarified that non-infected birds and ZONPs-fed birds had significantly higher standing and feeding activities and lower resting activities in comparison with the infected group. Also, the S. aureus infected group had significantly lower body weight gain (BWG) and higher feed conversion ratio (FCR) than the non-infected group. In addition, the non-infected birds and ZONPs groups had significantly lower object crossing and tonic immobility times (TI) and gait scores (GS) in comparison with the S. aureus group. Only ZONPs 30, 40 ppm and non-infected groups had a significantly higher latency to lie time (LLT) and lower serum cortisol level in comparison with the S. aureus group. Moreover, there were significant changes in the gross lesion score and histopathological lesions between the different groups. In conclusion, the dietary supplementation of ZONPs can reduce S. aureus-induced negative effects of FPD in broilers.

Inactivation of E. coli Using Atmospheric Pressure Plasma Jet with Dry and Wet Argon Discharges.

The acceleration of inactivating viable cells of Escherichia coli (E. coli), by using new direct and indirect innovative methods, is the targeted method of using an atmospheric pressure plasma jet (APPJ) operated by an AC high-voltage power source with variable frequency up to 60 kHz and voltage ranging from 2.5 to 25 kV. Discharges using dry argon (0% O2) discharges and different wet argon discharges using admixtures with O2/Ar ratios ranging from 0.25% to 1.5% were studied. The combined effects of dry and wet argon discharges, direct and indirect exposure using a mesh controller, and hollow magnets were studied to reach a complete bacterial inactivation in short application times. Survival curves showed that the inactivation rate increased as the wettability increased. The application of magnetized non-thermal plasma discharge with a 1.5% wetness ratio causes a fast inactivation rate of microbes on surfaces, and a dramatic decrease of the residual survival of the bacterial ratio due to an increase in the jet width and the enhanced ability of fast transport of the charges to viable cells, especially at the edge of the Petri dish. The membrane damage of E. coli mechanism factors in the activation process by APPJ is discussed.

Hand Hygiene Knowledge, Perception, and Practices among Domestic Visitors to the Prophet's Mosque in Al Madinah City Amid the COVID-19 Pandemic: A Cross-Sectional Study.

This study aimed to assess hand hygiene knowledge, perception, and practices of visitors to the Prophet's Mosque in Al Madinah City, Saudi Arabia. Using a self-administered electronic questionnaire, a cross-sectional survey was conducted among domestic residents, who visited the mosque between 31 July and 3 August 2020. Participants' demographic data, hand hygiene knowledge, perception, and practices were collected. Four hundred participants aged 18-65 (median 36) years completed the survey, of which 215 (53.8%) were female. The visitors' mean knowledge score about hand hygiene was 6.4 (± standard deviation (SD) 1.35) of total 12. Most participants (392, 98%) were aware of the role of hand hygiene in preventing Coronavirus Disease 2019 (COVID-19); nevertheless, 384 (96%) said hand hygiene lowers body immunity and 316 (79%) thought <60% alcohol is sufficient for hand disinfection. Males had a higher knowledge score than females (6.46 (±1.41) vs. 6.14 (±1.27), p = 0.02) and, visitors who had no formal education scored higher than those with post-graduate education (6.88 (±1.45) vs 5.73 (±1.12), p = 0.01). Washing hands with soap and water was the predominant method practiced after a meal (365, 91.7%), after toilet visit (354, 88.5%), after touching a surface (262, 65.7%), after waste disposal (332, 83.2%), and when hands were visibly dirty (357, 89.5%). Al Madinah visitors had moderate knowledge about hand hygiene, but demonstrated some knowledge gaps and negligence in practice that are crucial to curb the spread of COVID-19.

Prevalence of Methicillin-Resistant Staphylococcus aureus and Classical Enterotoxin Genes Among Sudanese Food Handlers.

Food handlers who carry enterotoxin-producing Staphylococcus aureus could become potential reservoirs of Staphylococcal food poisoning. The study is a cross-sectional one aimed to determine the prevalence of methicillin-resistant S. aureus (MRSA) and staphylococcal enterotoxins from randomly selected food handlers in Al Jazirah state, Sudan. Culture swabs were collected from the hands and nasals of food handlers (2016-2018). Identification of S. aureus was done on the basis of conventional laboratory tests. All S. aureus isolates were screened for MRSA and staphylococcal enterotoxin (SE) genes by polymerase chain reaction. The S. aureus strains were isolated from 25% of the collected culture swabs of which 42% were confirmed as MRSA. The existence of one or more of enterotoxin genes was confirmed in 34.4% of the isolated S. aureus strains. The combined staphylococcal enterotoxin genes were found in 9.6% of the isolates. The SE genes among MRSA strains (61.5%) were found to be higher than methicillin-sensitive S. aureus strains (14.8%). The most frequent staphylococcal enterotoxin genes were SEA (19.4%) followed by the SEB (8.6%), SEC (4.3%), and SED (2.1%). The carriage rate of MRSA strains demonstrated a higher rate of staphylococcal enterotoxins genes than methicillin-sensitive S. aureus. There is an increasing prevalence of MRSA compared with the previous rates and staphylococcal enterotoxin genes among Sudanese food handlers, which is a serious problem for public health.

Exploring Jolkinol D Derivatives To Overcome Multidrug Resistance in Cancer.

Macrocyclic monoacyl lathyrane derivatives bearing a benzoyl moiety were previously found to be strong ABCB1 modulators. To explore the effects of different substituents of the aromatic moiety, 14 new compounds (1.1-1.7, 1.10, and 2.1-2.4) were prepared from jolkinol D (1), obtained from Euphorbia piscatoria, and from jolkinodiol (2), its hydrolysis derivative. Compounds 1.8 and 1.9, having aliphatic moieties, were also obtained. The reversal of ABCB1-mediated MDR was evaluated through functional and chemosensitivity assays on the human ABCB1-gene-transfected L5178Y mouse T-lymphoma cell line. Structure-activity relationships showed that addition of electron-donating groups to the aromatic moiety improved the activity. The effects on the ATPase activity of the strongest modulator (1.3) and the inactive jolkinol D (1) were also investigated and compared. Moreover, in the chemosensitivity assay, most of the compounds interacted synergistically with doxorubicin. Compounds 1.1-1.10 and 2.1-2.4 were further assessed for their collateral sensitivity effect against the human cancer cells: EPG85-257 (gastric) and EPP85-181 (pancreatic), and the matching drug-selected cells EPG85-257RDB, EPG85-257RNOV, EPP85-181RDB, and EPP85-181RNOV. The most promising ones (1.8 and 1.10) along with compound 3, previously selected, were investigated as apoptosis inducers. The compounds were able to induce apoptosis through caspase-3 activation, with significant differences being observed between the parental and resistant cells.