Bacterial Contamination Research Articles

Preparation, characterization and properties of chitosan-coated Epsilon-poly-lysine nanoliposomes in apple juice

Epsilon-poly-lysine (EPL) is widely used in food preservatives. However, EPL can react with components in food substrates, resulting in the formation of precipitates that reduce its antimicrobial properties. Nanoencapsulation is a promising technique and represents a novel approach to enhance EPL activity. In this study, EPL nanoliposomes (EPLLP) were prepared by the thin film hydration method, and chitosan-coated nanoliposomes (CS-EPLLP) were developed by modifying EPLLP with 0.5 mg/mL chitosan. The obtained CS-EPLLP exhibited a spherical morphology with a particle size range of 85.27–89.77 nm, a polydispersity index (PDI) of 0.293–0.301, and an encapsulation efficiency of 83.01 ± 4.00 %. After 30 days of storage, no significant difference in particle size was observed and the PDI was <0.30. The release rate of EPLLP was up to 40 % in 1 h, while that of CS-EPLLP was <20 %. The physical and thermal stability of EPLLP could be effectively improved by chitosan. Moreover, CS-EPLLP could effectively eradicate A. acidocaldarius and A. acidoterrestris in apple juice at concentrations of 2.5 and 0.625 mg/L, respectively. The cytotoxicity test showed that CS-EPLLP exhibited excellent biocompatibility. Therefore, this study has developed a novel nanoliposome material that provides new insights into the control of bacterial contamination in fruit juices.

“All-on-a-Tube” POCT of Salmonella in large-volume sample

Point-of-care testing (POCT) of pathogenic bacteria at low concentrations is vital to early warning of bacterial contaminations. A disposable centrifuge tube was reconstructed in this study for sensitive Salmonella detection in large-volume samples, where the entire bacterial detection progress from separation to detection, was performed within the tube. The bottom of this centrifuge tube was assembled with a flexible stirrer containing a pair of circular magnets, which was rapidly rotated using a DC motor to produce the vortex for simultaneous mixing and capture of target bacteria. Besides, immune manganese dioxide nanoflowers were synthesized and used to label target bacteria, followed by mimicking catalyze colorless TMB substrate into blue TMBox product. The product image was captured and analyzed by a smartphone App to quantitatively determine the target bacteria. This POCT centrifuge tube effectively achieved a separation efficiency of approximately 80 % for target bacteria from a 10 mL sample, enabling the detection of target bacteria within the range of 1.3 × 101 to 1.3 × 104 CFU/mL in 1 h, with a low detection limit of 13 CFU/mL. More importantly, this reconstructed centrifuge tube demonstrated its potential as a laboratory consumable for bacterial detection in routine screening owing to the features of low cost, easy operation and high integration.

To the Studies on Pollution of Under Ground Water Mau City

The study focuses on the environmental evaluation and classification of the Mau City area, located in the eastern part of Uttar Pradesh, India. The investigation covers an area of approximately 20 km2 and includes a diverse population in terms of socio- economic, cultural, and geographical characteristics. The population data reveals significant growth, with a population increase from 168,716 in 1991 to 2,205,968 in 2011. Animal populations, including cattle and poultry, have also shown an increasing trend from 2018 to 2020. Fertilizer usage data between 2017 and 2020 indicates fluctuations in the consumption of nitrogen, phosphorus, and potassium, demonstrating potential agricultural impacts on the environment. Water quality analysis is a major part of this study, employing various methods to determine salinity, dissolved oxygen, biological oxygen demand (BOD), and chemical oxygen demand (COD). Salinity was measured through titration with silver nitrate, while oxygen levels were analyzed using different methods, including dissolved oxygen (DO) analysis. Results indicate variations in water quality across different sampling sites (S1-S6), with key parameters such as pH, turbidity, temperature, and bacterial contamination being recorded monthly for the years 2019 and 2020.The research also involves the collection and analysis of water samples using various devices, including water samplers, bottom samplers, and biological samplers. Methods such as the EDTA method for water hardness, the gravimetric method for sulfate determination, and the colorimetric analysis for iron and chromium concentrations were utilized to evaluate the pollutants in the water. The study provides critical insights into water quality degradation, highlighting the presence of various pollutants, including nitrates, sulfates, and heavy metals like chromium, copper, and iron.

An Updated Assessment of Safety Strategies for Platelet Blood Concentrates (PCs): A Short Review Article

Background: Platelet concentrates (PCs) are one of the most used blood components in blood banks due to their essential role in treating thrombocytopenia, and while viral transmission has been largely addressed, bacterial contamination of platelet concentrates (PCs) are still regarded as a crucial safety concern. Objective: This short review aimed to consolidate current knowledge on the strategies followed in blood banks to maximize the quality and shelf life of platelet concentrates (PCs). Different methods of each strategy were considered, focusing on outcomes related to approved and effective outcomes. Methods: The current study is based on PubMed, Wiley, and Web of Science databases to assess donor selection, bacterial screening, and pathogen reduction technologies utilized for PCs quality. All articles were collected until April 2024. Studies utilizing approved interventions and relevant hospital outcomes were inclusive. However, repetitive data and unapproved methods were among the exclusive criteria. Collected published manuscripts were reviewed. Results: The studies reviewed and referenced in this article consensus that pathogen reduction technologies (PRTs) utilizing Ultraviolet rays (UV) was found to be effective in eliminating various bacterial contamination. Furthermore, the need for donor and bacterial screening is still essential and could not be overlooked. Pathogen reduction technologies (PRTs) remain important and valid despite studies suggesting the reduced platelet concentrates (PCs) quality and the need for frequent transmission of PCs. Some studies even foresee pathogen reduction technologies (PRTs) as replacing the cultural bacterial detection methods. Conclusion:We conclude that preventing bacterial contamination in platelet concentrates (PCs) requires a multifaceted approach. However, future research should focus on optimizing these strategies while minimizing their potential adverse effects on platelet function and safet

Assessment of Fungi Infection on Clarias anguillaris (Linnaeus, 1758) and Oreochromis niloticus (Linnaeus, 1758), Two Fish Species Farmed in Burkina Faso

Worlwide, fungi are by far the most common pathogen in fish farming. They are responsible of important economic losses in the fishery sector. However, in Burkina Faso knowledge of fungi infecting farmed fish are scarce. As a consequence, the prevalence as well as the effect of these pathogens are not known. A study was carried out on fungal infection of farmed fish. It aimed to evaluate the diversity of fungi associated with Oreochromis niloticus (Linnaeus, 1758) and Clarias anguillaris (Linnaeus, 1758) farmed in Burkina Faso. In total, 89 individuals of fish consisted of 47 specimens of Oreochromis niloticus and 42 specimens of Clarias anguillaris were collected from eleven fish farms. Swabs were taken on fish bodies and inoculated in Malt Extract Agar (MEA). The chloramphenicol was added to avoid bacterial contamination. Seventy-seven (77) fish were infected by fungi (85.51%). Four genera including Aspergillus (four species), Rhizopus (one species), Penicillium (one species) and Mucor (one species) were isolated. Small and big fish were all infected. This study shows fungi as a potential factor that impacts fish farming and suggests a need for more research on their effect on fish. Knowledge of fish parasites like fungi will allow to set effective means of fish pathology control, which once implemented will lead to an increase in fish farming productivity.

Assessment of Antibiotic Resistance in Groundwater Bacterial Strains: A Community-based Study

Background: The microbial quality of private and community water supply from groundwater is mostly not monitored nor assessed by any established government agencies in Nigeria. Contamination by pathogenic and antimicrobial resistant microbial agent, and the potential of resistant genes transfer from environmental bacteria to human pathogens is a major risk for public health in these water systems. Aim: This study was aimed at evaluating the microbiological quality and safety in terms of antibiotic resistance bacterial profile of groundwater sources in a typical peri-urban settlement in Nigeria. Methodology: Bacterial contaminants were isolated by membrane filtration technique, characterized and analyzed using standard microbiological approach. Results: A total of 22 and 8 Gram negative and positive bacteria respectively were isolated. The isolates comprised 7 bacterial genera with Klebsiella and Enterobacter species having the highest incidence of 20% respectively, followed by Bacillus (17%) and least being Shigella with 7% incidence. All the isolates were 100% resistant to cefotaxime, followed by 76.7% and 73.3% resistant to vancomycin and meropenem respectively. The least resistance of 3.3% was against ciprofloxacin. Resistance in borehole storage tank water was highest (80%) against vancomycin followed by 70% for meropenem, while 75% resistance was against vancomycin and meropenem respectively in the well water, Seventy-three percent (73%) of the isolates showed multidrug resistance (MDR) pattern, and a multiple antibiotic resistant index (MARI) ≥ 0.3. Conclusion: The results of this study suggest that groundwater source in the studied community is contaminated with antibiotic resistant bacteria and underscores the public health implication and concern for monitoring of groundwater supply in Nigerian communities.

Fusarium spp. in Metalworking Fluid Systems: Companions Forever

Water-miscible metalworking fluids (MWFs) are utilized in a variety of metal removal and forming operations. For end-use, formulation concentrates are diluted in water, creating conditions conducive to microbial growth and metabolism, possibly compromising the fluid’s integrity and mechanically obstructing filters or piping systems. Metalworking machines offer additional habitats on surfaces that are in permanent or temporary contact with MWFs. For that reason, biocides have been incorporated into concentrates for years, but legal constraints will restrain their use in the future. While bacterial contamination of MWFs is well documented, fungal contamination is often overseen and infrequently reported in the literature. In this study, we report fungal prevalence in in-use MWFs sampled worldwide over 10 years, and we are convinced that the presence of fungi is the norm rather than the exception. In addition, we evaluated the inhibitory effect of fungicides on fungal growth, sporulation and spore viability using traditional culture-dependent methods and flow cytometry. In essence, we show that the effectiveness of these fungicides is limited and dependent on the chemical construction of the fluid. We think that the ecology created by water-diluted MWFs is of higher importance than the anti-fungal activity of single components.

Faucets and keyboards as a major reservoir of gram-negative bacilli in a regional hospital in Northeast Brazil

Infections related to healthcare assistance represent a major public health problem worldwide, and the main etiological agents associated with these infections are microorganisms also found on inanimate hospital surfaces. Therefore, understanding the dynamics of bacterial contamination of hospital surfaces is essential for professionals working in these services. Objective: To evaluate the contamination of inanimate surfaces by Gram-negative bacilli (GNB) in a Regional Hospital in Northeast Brazil. Methods: This is an observational and cross-sectional study. Samples were collected from different hospital wards using a sterile swab soaked in saline solution. They were then plated on MacConkey agar and incubated at 36°C for 48 hours. The bacterial isolates were counted and identified using the Gram staining method, TSI agar, and oxidase test. Results: Out of the 150 samples collected, 71 showed no microbiological growth, 11 showed growth of filamentous fungi, and 66 showed growth of Colony Forming Units (CFU). A total of 132 morphologically distinct colonies were identified, with 55 identified as yeasts and 77 as GNB. In the evaluation of hospital wards, the Adult Emergency Room and the Orthopedic Surgical Clinic showed the highest growth of GNB. Regarding the surfaces studied, the most contaminated were faucets, computer keyboards, mattresses, and beds. Conclusions: Hospital areas with higher human traffic are the most contaminated, particularly on frequently handled objects. Therefore, it is necessary to focus on disinfecting these surfaces to break the transmission chain of these etiological agents.

Bacterial profile and antimicrobial susceptibility patterns of isolates from inanimate objects used by healthcare professionals at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia.

Healthcare-associated infections occur in patients under medical care, which is a major public health issue in hospitals worldwide. The prevalence is two to three folds higher in developing countries compared to developed countries. Inanimate objects used by healthcare professionals such as gowns, mobile phones, and stethoscopes are highly prone to bacterial contamination from the healthcare setting. In Ethiopia, there is a paucity of published data on the bacterial profile and susceptibility patterns of an isolates. To determine the bacterial profile and antimicrobial susceptibility patterns from inanimate objects used by healthcare professionals and associated factors at Debre Markos Comprehensive Specialized Hospital, Northwest Ethiopia. A cross-sectional study was conducted at Debre Markos Comprehensive Specialized Hospital from inanimate objects from April 10, 2023 to June 30, 2023 using simple random sampling technique with lottery method. Socio-demographic data was collected using a structured questionnaire. A swab sample from healthcare professionals' gowns, mobile phones, and stethoscopes were collected and inoculated onto blood agar, chocolate and MacConkey agar. Isolates were identified and characterized by colony morphology, Gram staining and biochemical tests. Antimicrobial susceptibility testing was performed in all isolates by the disk diffusion technique on Muller Hinton agar according to CLSI, 2022 guidelines. Data was entered into EPI-Data and analyzed using SPSS version 25. Logistic regression model was used. Variables with p-value ≤ 0.25 in bivariable logistic regression was fitted to multivariate logistic regression analysis. A p-value of ≤ 0.05 with 95%CI was considered statistically significant. A total of 376 healthcare professionals' inanimate objects were included from 191 study participants. Overall, 60.1% (226/376) (95%CI: 55.1-65) inanimate objects were contaminated. The proportion of bacterial contamination was (65.1%; 82/126), (60.3%; 76/126) and (54.8%; 68/124) for mobile phones, gowns and stethoscopes, respectively. Staphylococcus aureus was the most frequent isolate accounting (22.1%; 83/376) followed by Staphylococcus epidermidis (17.0%; 64/376), Escherichia coli (8.8%; 33/376) and Pseudomonas aeruginosa (4.9%; 18/376). Working in gynecology/ obstetrics wards (AOR: 8.69; 95%CI: 1.09-69.41, P = 0.041), did not disinfect mobile phones (AOR: 2.69; 95%CI: 1.15-6.25; P = 0.021) and stethoscopes regularly (AOR: 3.06, 95%CI: 1.23-7.59; P = 0.016), carry mobile phones with patient care materials (AOR: 2.72; 95%CI: 1.18-6.29, P = 0.019) and not taken infection prevention training (AOR:3.91; 95%CI:1.71-8.93; P = 0.001) were significantly associated with bacterial contamination.Most Gram-negative bacteria were resistant to ampicillin, trimethoprim-sulfamethoxazole and amoxacilline-clavunic acid, while Gram-positive isolates showed high level of resistant to penicillin. On the other hand, meropenem, for Gram-negative and clindamycin for Gram-positive bacteria showed lower level of resistance. Multidrug resistance among Gram-positive and Gram-negative bacteria were (62.6%; 92/147) and (75.3%; 64/85), respectively with over all MDR (67.2%, 156/232). Inanimate objects commonly used by healthcare professionals are important sources of bacterial contamination. S. aureus, S. epidermidis and E. coli were the predominant isolates. Most Gram-negative bacteria were resistant to ampicillin while Gram-positive isolates showed high level of resistant to penicillin. All healthcare professionals should regularly disinfect their inanimate objects to prevent bacterial colonization and potential spread of infection.

Prevalence and identification of Bacillus species in cellophane, foil, and disposable plastic containers used for food packaging

Background: Foil, cellophane, and disposable plastic containers are commonly employed in food packaging, namely as coatings on food items. Nevertheless, the existence of microbes on the surface and inside the internal composition of these materials gives rise to concerns, as they have the capacity to multiply under ideal circumstances and spread to food items, thereby jeopardizing the safety and quality of the food. Objective: This study aimed at examining the number of microorganisms and identifying specific bacterial species within frequently used food packaging materials like foil, cellophane, and disposable plastic containers. Methods: samples of foil, cellophane, and disposable plastic containers were collected from various popular brands in Iran. The overall bacterial count wضas determined using defibering, flooding, and smear techniques followed by culturing on Tryptone Glucose Extract Agar (TGEA) medium. To identify the bacterial species, various biochemical tests were performed, including fermentation, motility testing, catalase test, oxidase test, and methyl red-Voges Proskauer (MR-VP) test. Results: Bacterial quantity ranged from 0 CFU/g to 8.3 × 103 CFU/g in analyzed samples. All the samples had primary contaminants mainly Bacillaceae family bacteria that could produce spores. Disposable plastic containers had the lowest bacterial count whereas cellophane showed the highest bacterial contamination level. Among Bacillaceae family members Bacillus licheniformis was dominant. Conclusion: The study's findings emphasize the possibility of microbial contamination in food packaging materials, including cellophane. These results indicate that the food packaging industry should adopt a rigorous approach to hazard evaluation and Important Control Points (HACCP) in order to guarantee the microbiological safety and efficacy of packaging materials.

The incidence and risk factors of intraoperative bacterial contamination in primary total knee arthroplasty

BackgroundInfection is a devasting complication after arthroplasty. Identifying potential sources contributing to intraoperative bacterial transmission can help to reduce surgical-site infections.ObjectiveThe aim of this study was to identify the incidence and risk factors of intraoperative bacterial contamination (IBC) in primary total knee arthroplasty (TKA) procedures.MethodsActive surveillance cultures were used to detect IBC from 125 consecutive unilateral primary TKAs. The cultures were taken from different sites (surgical instruments, gloves of surgeons and surgical incisions) at different time points (before surgery, 30 min and at the end of the surgery) during arthroplasty procedures. Patient characteristics, including age, height, body weight, body mass index, comorbidity of diabetes mellitus, operative duration, intraoperative blood loss, types of prophylactic antibiotics were recorded. The white blood cell level before, the 3rd and 7th day after surgery were measured and recorded. In addition, patients were also followed for fever and surgical-site infections within 14 days after surgery.ResultsIn total, 1,000 cultures were taken. 91 (9.1%) of them showed an IBC. None of bacterial cultures of gloves and instruments before surgery were positive. At 30 min from the beginning of the procedure, 29 cultures (7.7%) from 16 patients (12.8%) showed a contamination. At the end of the surgery, 62 cultures (16.5%) from 32 patients (25.6%) showed a contamination. There were 15 cases (12.0%) of fever within 14 days after surgery, of which 11 cases with IBC, and 4 cases without IBC. No postoperative surgical-site infection occurred in all consecutive unilateral primary TKAs. The binomial logistic regression analyses confirmed that operative duration was the risk factor of IBC [OR 1.137 (95% CI 1.023 to 1.322), p = 0.014]. Moreover, compared to control group, the patients with IBC had a greater change of white blood cell level in the 3rd day after surgery (p = 0.022), and a higher risk of fever within 14 days after surgery (p &amp;lt; 0.001).ConclusionThe bacterial contamination rate during primary TKA is relatively high, despite the practice of standard preventive measures. Intraoperative bacterial contamination increases with long operating time, which may be one of the factors contributing to fever and leukocytosis after surgery.

Validation of the technological process for the production of riamilovir-based solution for aerodispersible administration

BACKGROUND: An important step in the production of riamilovir-based solution for inhalation administration is the validation of critical stages of the technological process. First, a detailed study of all production steps, from the preparation of the initial ingredients to the final packaging, is carried out. Control tests are then conducted, including measuring key process parameters and analyzing the physical and chemical properties of the solution. One of the important aspects of process validation is also the training of production personnel. Proper understanding and adherence to all process instructions and requirements ensures that the process is followed correctly. AIM: Carry out validation activities throughout the stages of the technological process for the production of a solution for inhalation administration based on the active substance “riamilovir”. MATERIALS AND METHODS: The study was carried out using the developed Pilot Industrial Regulations for the production of the medicina. The quality assessment of pharmaceutical substances, excipients and pilot samples was carried out in accordance with the requirements of the State Pharmacopoeia of the Russian Federation and GMP rules. RESULTS: It has been established that the technological scheme for the production of a solution based on the active substance “riamilovir” contains 6 main stages. The greatest risk is observed at the following stages: Auxiliary work 3. Obtaining water — risk of bacterial contamination. Тechnological process 4. Preparation and sterilizing filtration of the solution — risks of insufficient concentration and unsterility of the solution. Тechnological process 5. Dosing the solution into vials is a risk due to underfilling, as well as violation of sterility. CONCLUSION: Validation of the technological process of production of solution for inhalation administration based on the active substance “riamilovir” has been carried out. Critical stages in the technological production process have been identified. The optimal parameters of the technological process have been determined and documented, leading to a predictable result — the release of a high-quality and safe drug.

Isolasi Staphylococcus aureus dari swab tangan penjamah makanan di kantin Universitas Mataram

One of the main qualities of food is seen from the biological safety aspect, such as being free from Pathogenic microorganisms. Staphylococcus aureus is a pathogenic bacterium that can contaminate food ingredients come from the skin of food handlers. S. aureus produces enterotoxins that have a poisoning in consumers.The preliminary observationstated that there were still many food handlers in the Mataram University canteen who did not pay attention to hand hygiene and personal sanitation. This study aims to determine the bacterial contamination of S. aureus swabbed from the hands of food handlers in the Mataram University cafetaria. The method was used in this research is descriptive observational. The research consisted of two stages, namely isolation and biochemical identification. The isolation stage resulted 10 culturable bacterial isolates. All bacteria were able to ferment mannitol on Mannitol Salt Then, the biochemical test identification resulted that all isolates had a positive catalase test, a positive slide coagulase test, Gram-positive, and staphylococci cell. The TSIA test resulted A/A or (acid)/(acid) which indicated that all isolates were able to use diverse carbon sources from sucrose, lactose, glucose. Moreover, other test as sulfur, indole and motility tests were negative. Therefore, all isolates in this study are classified as S. aureus. This research is also a promotive and preventive effort for the campus in implementing hygiene and sanitation for food handlers in the cafetaria.

Antibacterial double-layer calcium phosphate/chitosan composite coating on metal implants for tissue engineering

In this study, four different promising two-layer composite coatings on titanium substrates with antibacterial properties were investigated. Two different types of antibacterial agents were used to impart antibacterial properties to the coatings: antibiotic amikacin (in three different concentrations) and zinc. Chitosan, which also has antibacterial properties, was used as a carrier layer for amikacin on a calcium phosphate coating incorporating zinc. This combination should enable long-term antibacterial properties of a bone implant and thus prevent potential complications during wound healing due to bacterial contamination. To examine the physico-chemical properties of the samples, the elemental, chemical and phase compositions, the thickness and the wettability of the coatings were investigated. The release of amikacin from the chitosan coatings was investigated using high-performance liquid chromatography. Antibacterial activity of the prepared coatings was evaluated against five hospital bacteria strains (Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus faecalis, Klebsiella pneumoniae) and one strain from the microbial strain collection (methicillin-resistant Staphylococcus aureus, ATCC 43300). To investigate the cell toxicity of the composite coating, cell adhesion, proliferation and osteogenic differentiation were tested with mesenchymal stem cells. According to the results, the composite coatings with an amikacin concentration of 5.0 and 7.5 percent by weight have the best biological and antibacterial properties.

Control of bacterial contamination in three types of fish selected from the coastal and inland regions of Tipaza (Algeria)

This study addresses the problem of microbiological contamination in fish sold in the region of Tipaza, where food safety is a growing concern. It aims to assess the contamination levels in three fish species: sardine, mackerel saurale, and bogue. To achieve this, samples were collected and analyzed for total aerobic mesophilic bacteria, thermotolerant coliforms, coagulase-positive Staphylococcus aureus, and Salmonella. The results revealed that all samples contained total aerobic mesophilic bacteria and thermotolerant coliforms within acceptable limits. However, high levels of coagulase-positive Staphylococcus aureus were detected in bogue and saurale samples, indicating unsatisfactory bacteriological quality, particularly in samples from the city of Tipaza. No Salmonella contamination was observed. These findings highlight significant hygiene issues during fish transport and sale, contributing to microbial contamination. The study concludes that improving handling practices is crucial to ensuring fish safety and reducing health risks to consumers.

An Etiology of Sputum Culture Contamination and their Drugs Susceptibility Patterns among TB-suspected Patients at Epicentre Mbarara Research Centre, Uganda

Aims: Contamination in TB cultures is problematic as it allows the growth of non-target bacterial or fungal species in sputum samples, potentially concealing M. tuberculosis. This study aimed to determine the prevalence, characterization, and drug susceptibility patterns of contaminants in sputum cultures from TB-suspected patients. Methods: A laboratory-based cross-sectional study was conducted from October 2023 to June 2024 at the Epicentre Mbarara Research Centre, involving 81 sputum samples from TB-suspected patients. Conventional decontamination procedures were used, and both solid Lowenstein Jensen (LJ) and liquid Mycobacterium Growth Indicator Tube (MGIT) culture methods were applied. Standard culture techniques and physicochemical analyses were employed. Bacteria were incubated at 37°C in O2 and Co2 incubators, with growth observed within 24 to 48 hours and up to three days for yeast contaminants. Sabouraud Dextrose Agar cultures were monitored for two weeks for filamentous fungi. Antibiograms for bacterial isolates were determined using the Kirby-Bauer, while broth microdilution was used for fungal isolates. Results: Of 81 samples, 14(17.28%) were contaminated. The most common bacterial contaminants were Staphylococcus aureus, Bacillus subtilis, Streptococcus viridans, Staphylococcus epidermidis, and Escherichia coli. Fungal contaminants included Aspergillus flavus, Penicillium species, Candida albicans, Cryptococcus neoformans, and non-albican Candida species. High resistance to erythromycin (73%) and tetracycline (50%) was noted among bacterial isolates, with sensitivity to vancomycin (67%), gentamycin (60%), and chloramphenicol (58%). Yeast isolates showed (87.5%) susceptibility to itraconazole and (75%) to amphotericin B but (50%) resistance to 5-flucytosine. Mold isolates exhibited (100%) susceptibility to itraconazole, amphotericin B, and 5-flucytosine but complete resistance to caspofungin. Conclusion: The level of contamination in TB cultures was noted, and Staphylococcus aureus and Candida albicans were observed as the most common contaminants. Bacterial isolates resisted erythromycin and tetracycline, while fungal isolates were generally susceptible to itraconazole and amphotericin B. We recommend Strengthening decontamination and monitoring common resistant contaminants.

Bacterial contamination of autologous blood salvaged during deceased donor liver transplantation: a prospective observational study.

Decompensated cirrhotic patients experience severely increased intestinal permeability and bacterial translocation. Thus, autologous blood salvaged during deceased donor liver transplantation (DDLT) may be contaminated with enteric bacteria. We aimed to evaluate bacterial contamination of autologous blood salvaged during DDLT and its association with post-transplant bacteremia. In 30 patients undergoing DDLT, bacterial culture was performed in salvaged autologous blood samples: one before graft reperfusion (non-leukoreduced) and two after graft reperfusion (non-leukoreduced and leukoreduced). The primary outcome was bacterial contamination of salvaged autologous blood. Seven of 30 patients (23.3%) were positive for bacteria (3 enteric/4 non-enteric) before graft reperfusion while 11 patients (36.7%) were positive (5 enteric/6 non-enteric) after graft reperfusion. Six of 7 patients who were positive for bacteria before graft reperfusion were positive after graft reperfusion with the same bacteria. Only 4 of 11 contaminated blood samples were converted to negative after leukoreduction. Post-transplant bacteremia risk was insignificantly greater in patients who received autologous blood with bacteria than in patients without bacteria (30.0% vs. 5.0%, P = 0.06). We found contamination of salvaged autologous blood with enteric bacteria throughout DDLT and incomplete performance of leukoreduction, indicating high bacterial load. The potential association between contaminated autotransfusion and post-transplant bacteremia warrants further validation in a larger prospective study.Clinical trial notation: This study was registered at the Clinical Research Information Service (CRiS; https://cris.nih.go.kr ; No. KCT0007223; principal registration investigator: Sangbin Han, date of registration: April 25, 2022).

Circadian rhythm and daytime variation do not affect intraoperative bacterial sternal contamination and postoperative wound infections following cardiac surgery

Studies have documented various effects of circadian rhythm and daytime variations on the cardiovascular and immune system as well as wound healing. From June to December 2016, n = 367 cardiac surgery patients were enrolled. Microbiological swabs from the mediastinum and subcutaneous wound were taken before sternal closure. Patients were assigned to groups based on operation start: morning (n = 219) or afternoon (n = 135). Bacterial contamination and wound infections were studied in relation to circadian rhythm and daytime variation. We did not observe any difference in mortality (morning: 3.7%, afternoon: 3.0%, p > 0.99) and major adverse events (morning: 8.2%, afternoon: 5.9%, p = 0.53). In 27.7% of the morning group, at least one positive intraoperative swab was observed, similar to the afternoon group (25.6%, p = 0.71). The incidence of positive presternal swabs was 15.6% in the morning compared to 9.1% in the afternoon (p = 0.18). About 90% of the germs detected were part of the natural skin flora (e.g., Cutibacterium acnes and Staphylococcus epidermidis). The incidence of sternal wound infections was 7.3% (morning) and 3.0% (afternoon) (p = 0.18). We did not find differences in the incidence of intraoperative bacterial sternal contamination, nor postoperative infections, between patients who underwent cardiac surgery in the morning or afternoon.

Fractional-Order Mathematical Modeling of Methicillin- Resistant Staphylococcus aureus Transmission in Hospitals

This article investigates the environmental contamination and antibiotic exposure effect on the transmission dynamics of the Methicillin-Resistant Staphylococcus aureus (MRSA) model in hospitals using the fractional Adams–Bashforth–Moulton Method (ABMM). This epidemic model simulates the dynamics of patient populations, bacterial contamination, and healthcare worker safety under varying conditions. This model provides critical insights into the interactions between hospital practices, environmental factors, and infection dynamics, demonstrating the importance of symmetry in balancing hospital admission and discharge rates to manage infection spread effectively. The analysis extends to the impact of environmental bacterial density and hospital admission rates on patient colonization. Increasing admission rates introduce more susceptible patients, exacerbating infection spread when bacterial density is high. Conversely, lower admission rates and bacterial density result in a more controlled infection environment. The model further investigates how varying discharge rates influence colonization dynamics, highlighting that effective discharge practices can mitigate infection spread, especially in high-bacterial density scenarios. It must be noted that this model is studied fractionally for the first time. Overall, this model provides critical insights into the interactions between hospital practices, environmental factors, and infection dynamics, offering valuable guidance for infection control strategies and hospital policy formulation. By adjusting fractional order constant (σ) values and analyzing different scenarios, this research aids in understanding and managing bacterial infections in healthcare settings. The proposed method is able to provide the results presented in the figures within this study considering the influence of many factors.

Urine Contamination Prevalence Using a Midstream Collection Device Compared with Clean Voided Collections in Dogs.

Collecting clean-caught voided urine samples is minimally invasive, but contamination occurs when urine passes through the nonsterile urethra and external genitalia. Discarding the initial urine stream may reduce these contaminants. This study hypothesized that using a midstream urine collection device would decrease bacterial and cellular contamination as compared with cleanly caught voided urine. This descriptive cross-sectional study collected urine from dogs using standard clean-caught (SCC), midstream collection device (MCD), and cystocentesis (CYS) techniques. Urinalysis and aerobic urine culture characteristics were recorded with each characteristic's prevalence described using percentages and 95% confidence intervals for each mode of collection. Positive urine culture prevalence did not differ between SCC and MCD (adjusted P value = .099); however, CYS had a lower prevalence compared with SCC and MCD (adjusted P values of <.001 [CYS versus SCC] and 0.009 [CYS versus MCD]). For other variables, there was no difference in prevalence when comparing SCC with MCD. There was no identified advantage to collecting urine using an MCD as compared with the SCC technique. Either option is a suitable alternative when CYS is not practical; however, clinicians need to interpret results cautiously because bacterial contamination is more common as compared with CYS.