Microbiological profile of peri-implantitis: Analyses of peri-implant microbiome

PURPOSE

To characterize the microbiome composition in peri-implant pocket of peri-implantitis and peri-implant sulcus controls using 16S rRNA gene sequencing.

MATERIALS AND METHODS

In this controlled clinical cross-sectional study, 23 subjects with control implants (n = 14) and diseased implants (peri-implantitis, n = 21) were included. The peri-implant pocket/sulcus was sampled and used to extract DNA and amplify the 16S rRNA gene using universal primers targeting the V3-V4 regions. The resulting 16S PCR amplicons were sequenced on Illumina MiSeq, and the sequences were processed using DADA2 and the Human Oral Microbiome Database (HOMD) as references. Alpha and Beta diversity, as well as core microbiome and differential abundance analyses, were performed using the MicrobiomeAnalyst workflow.

RESULTS

There were no significant differences in microbial diversity between control implants and implants with peri-implantitis (Shannon p = 0.82). Overall bacterial community structure assessed through beta diversity analysis was also not significantly different between the two groups (p = 0.18). However, high levels of Gram-negative bacteria were detected in peri-implant pockets compared to the control sulcus. Abundant species in peri-implantitis were Capnocytophaga leadbetteri, Treponema maltophilum, Peptostreptococcus, Neisseria, P. gingivalis, and Porphyromonas endodontali, Lactococcus lactis and Filifactor alocis (p < 0.05). Gram-positive bacteria such as Streptococcus salivaris, Prevotella melaninogenica, L. wadei, and Actinomyces spp. serve were more abundant in peri-implant control sulcus.

CONCLUSIONS

Peri-implant sulcus in control implants harbors predominantly Gram-positive bacteria, whereas pockets of implants with peri-implantitis harbor predominantly Gram-negative bacteria.

Microbiological, physicochemical and sensory changes throughout ripening of an experimental soft smear-ripened cheese in relation to salt concentrations

To evaluate the sodium chloride content effect on microbiological, biochemical, physicochemical and sensorial characteristics, Munster cheeses were prepared from pasteurized milk seeded with 3 yeasts (Kluyveromyces marxianus, Debaryomyces hansenii, Geotrichum candidum) and 5 ripening bacteria (Arthrobacter arilaitensis, Brevibacterium aurantiacum, Corynebacterium casei, Hafnia alvei, and Staphylococcus equorum). Experiments were performed under 1.0%, 1.7% and 2.4% NaCl levels in cheese in triplicate. Ripening (d2 - d27) was carried under 12°C and 96% RH. These kinetics were both reproducible and repeatable at 99% confidence level. For each microbial, biochemical and physicochemical parameter, 2 kinetic descriptors (maximal or minimal rate and its occurrence time) were defined. On d2 the physicochemical variables (water activity, dry matter, water content) were strongly dependent on the salting level. From d2 to d27 K. lactis was insensitive to salt while D. hansenii was stimulated. G. candidum growth appeared very sensitive to salt in cheese: at 1.0% NaCl G. candidum exhibited overgrowth, negatively impacting rind appearance, underrind consistency and thickness and off-flavor flaws. Salt concentration of 2.4% induced death of G. candidum. Four bacteria (A. arilaitensis, B. aurantiacum, C. casei, and H. alvei) were moderately sensitive to salt while S. equorum was insensitive to it. Salt level in cheese had a significant effect on carbon substrate consumption rates. Lactate consumption rate in 1.0% salted cheeses was approximately twice higher than under 2.4% NaCl. Data analysis of microorganism, biochemical, and physicochemical kinetics and sensory analysis showed that the best salt level in Munster-type cheeses to achieve an optimum balance between cheese characteristics, sensory qualities and marketability was 1.7% NaCl.

Microbiological Characteristics and Resistance Patterns in a Neonatal Intensive Care Unit: A Retrospective Surveillance Study

BACKGROUND AND OBJECTIVE

This study aims to assess the prevalence and antimicrobial susceptibility patterns of bacterial infections associated with both early-onset sepsis (EOS) and late-onset sepsis (LOS).

METHODOLOGY

This descriptive retrospective surveillance research was conducted on all neonates admitted to the neonatal ICU with bacterial sepsis, where positive cultures were isolated from sterile sites (either cerebrospinal fluid or blood) at Tawam Hospital, Al Ain, Emirate of Abu Dhabi, UAE, from January 2012 and December 2021. Antimicrobial susceptibility analysis was performed.

RESULTS

The incidence of LOS (94.43%) was higher compared to EOS (5.56%). The most prevalent isolates (59.2%) were gram-positive bacteria, with gram-negative bacteria accounting for 40.8%. The leading isolates included coagulase-negative Staphylococci (CONS, 40.98%), Klebsiella (16.04%), Staphylococcus aureus (8.46%), Escherichia coli (8.24%), Pseudomonas (7.57%), and Group B Streptococcus (GBS, 5.12%). CONS were predominant in LOS cases (42.9%), while GBS was the main pathogen in EOS cases (44%).

CONCLUSIONS

We observed reduced resistance levels of CONS against ampicillin, benzylpenicillin, clindamycin, erythromycin, fusidic acid, gentamicin, oxacillin, rifampicin, and trimethoprim/sulfa. S. aureus exhibited increased resistance to erythromycin, fusidic acid, gentamicin, and levofloxacin, while E. coli demonstrated decreased resistance against cephalothin, gentamicin, and trimethoprim/sulfa. The antibiotics currently employed empirically appear to provide adequate coverage against the most prevalent bacteria causing early- and late-onset neonatal infections.

A Review on Microbiological Source Attribution Methods of Human Salmonellosis: From Subtyping to Whole-Genome Sequencing

Salmonella is one of the main causes of human foodborne illness. It is endemic worldwide, with different animals and animal-based food products as reservoirs and vehicles of infection. Identifying animal reservoirs and potential transmission pathways of Salmonella is essential for prevention and control. There are many approaches for source attribution, each using different statistical models and data streams. Some aim to identify the animal reservoir, while others aim to determine the point at which exposure occurred. With the advance of whole-genome sequencing (WGS) technologies, new source attribution models will greatly benefit from the discriminating power gained with WGS. This review discusses some key source attribution methods and their mathematical and statistical tools. We also highlight recent studies utilizing WGS for source attribution and discuss open questions and challenges in developing new WGS methods. We aim to provide a better understanding of the current state of these methodologies with application to Salmonella and other foodborne pathogens that are common sources of illness in the poultry and human sectors.

Advances in machine learning-based bacteria analysis for forensic identification: identity, ethnicity, and site of occurrence

When faced with an unidentified body, identifying the victim can be challenging, particularly if physical characteristics are obscured or masked. In recent years, microbiological analysis in forensic science has emerged as a cutting-edge technology. It not only exhibits individual specificity, distinguishing different human biotraces from various sites of occurrence (e.g., gastrointestinal, oral, skin, respiratory, and genitourinary tracts), each hosting distinct bacterial species, but also offers insights into the accident's location and the surrounding environment. The integration of machine learning with microbiomics provides a substantial improvement in classifying bacterial species compares to traditional sequencing techniques. This review discusses the use of machine learning algorithms such as RF, SVM, ANN, DNN, regression, and BN for the detection and identification of various bacteria, including Bacillus anthracis, Acetobacter aceti, Staphylococcus aureus, and Streptococcus, among others. Deep leaning techniques, such as Convolutional Neural Networks (CNN) models and derivatives, are also employed to predict the victim's age, gender, lifestyle, and racial characteristics. It is anticipated that big data analytics and artificial intelligence will play a pivotal role in advancing forensic microbiology in the future.

Analysis of the Degradation of OCPs Contaminated Soil by the BC/nZVI Combined with Indigenous Microorganisms

Organochlorine pesticides (OCPs) were typical persistent organic pollutants that posed great hazards and high risks in soil. In this study, a peanut shell biochar-loaded nano zero-valent iron (BC/nZVI) material was prepared in combination with soil indigenous microorganisms to enhance the degradation of α-hexachlorocyclohexane(α-HCH) and γ-hexachlorocyclohexane(γ-HCH) in water and soil. The effects of BC/nZVI on indigenous microorganisms in soil were investigated based on the changes in redox potential and dehydrogenase activity in the soil. The results showed as follows: (1) The specific surface area of peanut shell biochar loaded with nano-zero-valent iron was large, and the nano-zero-valent iron particles were evenly distributed on the peanut shell biochar; (2) peanut shell BC/nZVI had a good degradation effect on α-HCH and γ-HCH in water, with degradation rates of 64.18% for α-HCH and 91.87% for γ-HCH in 24 h; (3) peanut shell BC/nZVI also had a good degradation effect on α-HCH and γ-HCH in soil, and the degradation rates of α-HCH and γ-HCH in the 1% BC/nZVI reached 55.2% and 85.4%, second only to 1% zero-valent iron. The degradation rate was the fastest from 0 to 7 days, while the soil oxidation-reduction potential (ORP) increased sharply. (4) The addition of BC/nZVI to the soil resulted in a significant increase in dehydrogenase activity, which further promoted the degradation of HCHs; the amount of HCHs degradation was significantly negatively correlated with dehydrogenase activity. This study provides a remediation strategy for HCH-contaminated sites, reducing the human health risk of HCHs in the soil while helping to improve the soil and increase the activity of soil microorganisms.

The clinical characteristics and microbiological investigation of pediatric burn patients with wound infections in a tertiary hospital in Ningbo, China: A ten-year retrospective study

Burn is one of the leading causes of death and disability in children worldwide, and wound infection is an excellent challenge in burn treatment. We performed a retrospective review of pediatric burn patients with wound infections to reveal their clinical data and investigate pathogens' distribution and drug resistance patterns to provide references for treatment. As a result, 330 pediatric burn patients with wound infections were identified; 65.8% (217/330) were < 2 years old. Most of the injuries were scalded and involved <10% total body surface area in size (TBSA), mainly causing II-degree burn and II + III-degree burn. Three hundred and fifty nine strains of pathogens were isolated, the primary pathogens were Staphylococcus aureus (45.4%) and Pseudomonas aeruginosa (18.7%). Both S. aureus and P. aeruginosa isolated from 2012 to 2016 were more likely to be multi-resistant than those isolated from 2017 to 2021, as they were significantly associated with resistance to ≥4 Clinical and Laboratory Standard Institute (CLSI) classes (p = 0.040 and 0.006, respectively). In conclusion, children aged <2 years old were the main pediatric burn patients with wound infections. The primary bacteria isolated from the wound were S. aureus and P. aeruginosa, with a decreasing tendency of multi-resistance.

Sign of the Times: Updating Infective Endocarditis Diagnostic Criteria to Recognize Enterococcus faecalis as a Typical Endocarditis Bacterium

The modified Duke criteria requires that Enterococcus faecalis bacteremia must be both community-acquired and without known focus in order to be considered a microbiological "Major" diagnostic criterion in the diagnosis of infective endocarditis. We believe that the microbiological diagnostic criteria should be updated to regard E. faecalis as a "typical" endocarditis bacterium as is currently the case, for example, viridans group streptococci and Staphylococcus aureus. Using data from a prospective study of 344 patients with E. faecalis bacteremia evaluated with echocardiography, we demonstrate that designating E. faecalis as a "typical" endocarditis pathogen, regardless the place of acquisition or the portal of entry, improved the sensitivity to correctly identify definite endocarditis from 70% (modified Duke criteria) to 96% (enterococcal adjusted Duke criteria).

Effects of High-Voltage Atmospheric Cold Plasma Treatment on Microbiological and Quality Characters of Tilapia Fillets

Cold plasma (CP) has become an alternative to conventional thermal processing of food products. In this study, the effect of cold plasma treatment time on the inactivation and quality of tilapia fillets was investigated. The surfaces of tilapia fillets were inoculated with Salmonella enteritis (S. enteritis), Listeria monocytogenes (L. monocytogenes), and a mixture of both before being treated with cold plasma at 70 kV for 0, 60, 120, 180, 240, and 300 s. With the extension of treatment time, the number of colonies on the surface of the fillets decreased gradually; after 300 s of cold plasma treatment, S. enteritis and L. monocytogenes populations were reduced by 2.34 log CFU/g and 1.69 log CFU/g, respectively, and the a* value and immobile water content decreased significantly (p < 0.05), while the free water content increased significantly (p < 0.05). TBARS value increased significantly (p < 0.05) to 1.83 mg MDA/kg for 300 s treatment. The carbonyl value and sulfhydryl value of sarcoplasmic protein significantly (p < 0.05) increased and decreased, respectively, as treatment time extension, while no significant changes were found in myofibrillar protein. No significant differences were observed in pH, b* value, elasticity, chewiness, thiol value, and TVB-N value. The results showed that cold plasma had an inactivation effect on tilapia fillets and could preserve their original safety indicators. It was concluded that CP treatment could be used as an effective non-thermal method to maintain the quality of tilapia fillets and extend their shelf-life.

Using a stacker crane for sterile storage in the operating theatre: initial environmental microbiological qualification

BACKGROUND

Adequate storage of sterile surgical devices must prevent contamination and the introduction of microbial contaminants inside the operating rooms. For functional and economic purposes, stacker cranes (STCs) could replace the traditional sterile storage room (TSSR). STCs are large multistage computer-assisted systems used to automatically store and retrieve loads from defined locations. However, their microbiological performance has not been evaluated AIM: As part of the opening of a new building that included an operating theatre, we qualified a new STC and compared its microbiological control performance to that of the previous TSSR.

METHODS

From December 2020 to March 2021, 590 environmental specimens (air, n=56; surfaces, n=534) were collected and interpreted according to the NF S90-351 French Association for Standardization standards.

FINDINGS

Thorough surface disinfection was not sufficient for controlling microbial contamination in the STC. Thus, the initial qualification testing was conducted following an aggressive aerial chemical decontamination of the STC. Despite the lack of a HEPA filtered air system, the overall non-conformity rates were lower in the STC than in TSSR (8.3% vs. 21.4%, p=0.33 for air, respectively, and 9.7% vs. 41.7% p<0.001 for surfaces). The air-controlled barrier in front of the loading zone appeared to be sufficient to prevent bacterial contamination. The presence of fungi must be carefully monitored.

CONCLUSION

This is the first study supporting the contribution of STCs in saving space and improving the maintenance of sterile surgical device storage and availability under acceptable environmental conditions. Further studies are needed to assess the long-term microbiological contamination inside the STC.

Changes in the microbiological, physicochemical properties of Chinese traditional fermented Suan rou at ripening fermentation

This study characterized the changes in the microbiological, physicochemical properties of Suan rou during fermentation via three different techniques (Technique A is a traditional production process. Based on technique A, technique B adds a total of 200 g of sucrose to the thinly sliced meat, and technique C changes the amount of salt in the thinly sliced meat to 200 grams.). Compared to batch A, the samples from batches B and C featured more rapid reduction in pH and generated more TA. Myofibrillar proteins in batches B and C showed higher degradation rate, and several low-molecular-weight metabolites were determined on the basis of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) gel lanes. The contents of thiobarbituric acid (TBARS) and total volatile base nitrogen (TVB-N) and the growth of spoilage bacteria and pathogens were suppressed in the three batches. A relatively compatible acid-salinity proportion was presented in the Suan rou of batches A and B compared with that of batch C. The results show that the Suan rou made by B technology was more palatable acid flavor and abundant nutrition.

BIKE: Dietary Exposure Model for Foodborne Microbiological and Chemical Hazards

BIKE is a Bayesian dietary exposure assessment model for microbiological and chemical hazards. A graphical user interface was developed for running the model and inspecting the results. It is based on connected Bayesian hierarchical models, utilizing OpenBUGS and R in tandem. According to occurrence and consumption data given as inputs, a specific BUGS code is automatically written for running the Bayesian model in the background. The user interface is based on shiny app. Chronic and acute exposures are estimated for chemical and microbiological hazards, respectively. Uncertainty and variability in exposures are visualized, and a few optional model structures can be used. Simulated synthetic data are provided with BIKE for an example, resembling real occurrence and consumption data. BIKE is open source and available from github.

V.I.T.A.M. in COVID 19: A Systematic Approach to a Global Pandemic

Introduction

In the unprecedented era of COVID-19, ongoing research and evolution of evidence has led to ever-changing guidelines for clinical monitoring and therapeutic options. Formulating treatment protocols requires the understanding and application of the evolving research.

Objective

The primary objective of this study is to present a systematic evidence-based approach to synthesize the necessary data in order to optimize the management of COVID-19.

Methods

At Mayo Clinic Florida, we developed a multidisciplinary centralized COVID Treatment Review Panel (TRP) of expert pulmonologists, intensivists, infectious disease specialists, anesthesiologists, hematologists, rheumatologists, and hospitalists that in real-time reviews the latest evidence in peer-reviewed journals, the available clinical trials, and help guide the rapid application of therapeutics or interventions to the patient and the bedside provider.

Results/Conclusions

The multi-disciplinary team approach of synthesizing clinical data and coordinating care is effective in responding to rapidly evolving and changing evidence. Systematic data collection and evidence-based treatment algorithms enable physicians to rapidly translate the current literature to clinical practice, and improve care and outcomes of patients.

Comparison of clinical and laboratory profile of pulmonary and extrapulmonary tuberculosis in children: A single-center experience from India

BACKGROUND

Pediatric tuberculosis (TB) is an indicator of the recent transmission of TB in the community. However, the diagnosis of pediatric TB poses a challenge to clinicians.

AIMS

We aimed to evaluate and compare the clinical and laboratory profile of pulmonary TB (PTB) and extra PTB (EPTB) in children and adolescents.

METHODS

In this retrospective observational study, children attending the pediatric TB clinic of All India Institute of Medical Sciences, Rishikesh, from August 2015 to July 2017 were included in the study. The medical case records of patients were reviewed for demography, clinical findings, investigations, and diagnosis. The clinical and laboratory characteristics of patients with PTB and EPTB were compared.

RESULTS

A total of 58 children included. Out of which, 33 (56.9%) had PTB, and 25 (43.1%) had EPTB. The EPTB cases included 15 (60%) pleural TB, 9 (36%) lymph node TB, and 1 (4%) TB meningitis patient. Fever, cough, and weight loss were the most common symptoms. Hilar lymphadenopathy was the most common radiological abnormality. Microbiological confirmation was possible in 54.5% of patients with PTB. Cough (aOR 70.326; 95% CI: 5.370-921.032) and microbiological confirmation (aOR 46.011; 95% CI: 2.073-1021.201) were more in PTB as compared to EPTB.

CONCLUSIONS

PTB and EPTB are common in children and adolescents. The typical clinical manifestations and positive microbiological confirmation are less common in EPTB than PTB.

RELEVANCE FOR PATIENTS

TB is one of the common communicable diseases in the developing world. Diagnosis of TB in children is often challenging. Our study results help in better understanding childhood TB and EPTB clinical features and have potential to increase diagnostic yield.

Morbidity and Mortality Associated with Typhoid Fever Among Hospitalized Patients in Hyderabad District, Pakistan, 2017-2018: Retrospective Record Review

BACKGROUND

Hyderabad, Pakistan, was the first city to witness an outbreak of extensively drug resistant (XDR) typhoid fever. The outbreak strain is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin, thus greatly limiting treatment options. However, despite over 5000 documented cases, information on mortality and morbidity has been limited.

OBJECTIVE

To address the existing knowledge gap, this study aimed to assess the morbidity and mortality associated with XDR and non-XDR Salmonella serovar Typhi infections in Pakistan.

METHODS

We reviewed the medical records of culture-confirmed typhoid cases in 5 hospitals in Hyderabad from October 1, 2016, to September 30, 2018. We recorded data on age, gender, onset of fever, physical examination, serological and microbiological test results, treatment before and during hospitalization, duration of hospitalization, complications, and deaths.

RESULTS

A total of 1452 culture-confirmed typhoid cases, including 947 (66%) XDR typhoid cases and 505 (34%) non-XDR typhoid cases, were identified. Overall, ≥1 complications were reported in 360 (38%) patients with XDR typhoid and 89 (18%) patients with non-XDR typhoid (P<.001). Ileal perforation was the most commonly reported complication in both patients with XDR typhoid (n=210, 23%) and patients with non-XDR typhoid (n=71, 14%) (P<.001). Overall, mortality was documented among 17 (1.8%) patients with XDR S Typhi infections and 3 (0.6%) patients with non-XDR S Typhi infections (P=.06).

CONCLUSIONS

As this first XDR typhoid outbreak continues to spread, the increased duration of illness before hospitalization and increased rate of complications have important implications for clinical care and medical costs and heighten the importance of prevention and control measures.

Characterization of Artisanal Spontaneous Sourdough Wheat Bread from Central Greece: Evaluation of Physico-Chemical, Microbiological, and Sensory Properties in Relation to Conventional Yeast Leavened Wheat Bread

In the present study, both yeast leavened bread (YLB) and artisanal sourdough wheat bread (SDB) were prepared. The physico-chemical, microbiological, and sensory properties of breads were monitored as a function of storage time (T = 25 °C). As expected, the titratable acidity (TA) values of SDB were higher than those of YLB. The aroma profile of SDB was similar to that of YLB, including classes of compounds such as alcohols, aldehydes, ketones, esters, organic acids, terpenes, and sulfur compounds; however, the concentrations between the two were different. Aroma deterioration of bread during storage was partly related to the loss of several volatiles. Texture and sensory analysis showed that SDB was harder, less elastic, but richer in aroma and light sour taste than YLB. Mold growth was apparent when the population of yeasts/molds reached approximately 4 log cfu/g. This yeast/mold count was reached on days 4–5 for YLB and day 18 + for SDB. A 16S amplicon meta-barcoding analysis showed that the bacterial profile of SDB was dominated by a single genus, (Lactobacillus). Analysis of the eukaryotic load showed that at the genus level, Saccharomyces and Alternaria were the most abundant genera, independently of the gene sequenced (18S or ITS). Based primarily on mold growth and texture data, which proved to be the most sensitive quality parameters, the shelf life was ca. 4–5 days for YLB and 10 days for SDB.

Effect of adding Aloe vera jell on the quality and sensory properties of yogurt

This study was planned to investigate the effect of replacing milk fat with aloe vera gel addition on yogurt quality. Purposely, yogurt was prepared with different concentration of aloe vera gel and coded as AGY0, = Control (3.5% fat and no AG), AGY1 = (1% fat and 1% AG), AGY2 = (1% fat and 2% AG), AGY3 = (1% fat and 3% AG), AGY4 = (2% fat and 1% AG), AGY5 = (2% fat and 2% AG), and AGY6 = (2% fat and 3% AG). Aloe vera gel yogurt was analyzed for physicochemical, microbial, and sensory characteristics with defined interval (0, 7th, 14th, and 21st) days. All attributes of the yogurt were significantly (0.05) affected by the addition of aloe vera gel. Results showed that the pH (4.6-4.05), viscosity (46.4-4.3), WHC (32.8%-26.1%), fat (0.9%-3.48%), protein (3.14%-3.36%), lactose (4.07%-4.23%), ash (0.48%-0.63%), total solids (11.08%-17.18%), SNF (7.69-l5.21%), and TPC (2.36 × 107 to 1.02 × 107 CFU/ml) values of yogurt samples decreased with storage time. However, acidity and syneresis of yogurt increased with the passage of time ranging from 1.12%-1.67% and 0.9-5 ml, respectively. In conclusion, aloe vera improved the texture of the yogurt which leads to higher consumer acceptability. Addition of 3% aloe vera to 1% fat (AGY3) containing buffalo milk yogurt was found to best for physicochemical as well as organoleptic characteristics as well as organoleptic characteristics.

Quality Assessment of Three Types of Drinking Water Sources in Guinea-Bissau

The lack of access to safe drinking water causes important health problems, mainly in developing countries. In the West African country Guinea-Bissau, waterborne diseases are recognised by WHO as major infectious diseases. This study analysed the microbiological and physicochemical parameters of drinking water in the capital Bissau and its surroundings. Twenty-two sites belonging to different water sources (piped water, tubewells and shallow wells) were surveyed twice a day for three weeks, in both dry and wet seasons. Most of the microbiological parameters were out of the acceptable ranges in all types of water and both seasons and tended to worsen in the wet season. Moreover, in Bissau, the levels of faecal contamination in piped water increased from the holes to the consumer (tap/fountain). Several physicochemical variables showed values out of the internationally accepted ranges. Both well sources showed low-pH water (4.87–5.59), with high nitrite and iron levels in the wet season and high hexavalent chromium concentration in the dry season. The residual chlorine never reached the minimum recommended level in any of the water sources or seasons, suggesting a high risk of contamination. Results reveal a lack of quality in the three water sources analysed, coherent with the high number of diarrheal cases in the country. There is an urgent need to improve sanitarian conditions to reduce the disease burden caused by these waterborne illnesses.

Effects of chitosan grafted phenolic acid coating on microbiological, physicochemical and protein changes of sea bass (Lateolabrax japonicus) during refrigerated storage

This project aimed to evaluate the effects of gallic acid (GA) and protocatechuic acid (PA) grafted onto chitosan (CS) on the improved quality of sea bass (Lateolabrax japonicus) during refrigerated storage. The incorporation of GA and PA onto CS (CS-g-GA and CS-g-PA) were achieved by the carbodiimide-mediated grafting procedure. Samples were treated with different solutions (deionized water [CK], 1% CS [m/v], 1% CS-g-GA [m/v], and 1% CS-g-PA [m/v]) for 10 min, which were then stored at 4 °C. Microbiological quality, including total viable counts (TVC), psychrophilic bacterial counts (PBC), Pseudomonas bacterial counts, and H₂ S-producing bacterial counts were measured. Physicochemical parameters, including pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) value, water holding capacity (WHC), and K value, were measured. The changes in protein characteristics, including sulfhydryl groups (SH), Ca²⁺ -ATPase activity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and tertiary structure of protein were analyzed periodically, along with texture profile analysis (TPA). The results demonstrated that the CS copolymers treatment exhibited better preservation effects. The CS-g-GA and CS-g-PA treatments could significantly inhibit the growth of microorganisms and retard the increase of pH, TVB-N, TBA, WHC, and K-value during refrigerated storage compared with the CK and CS groups. Additionally, the CS-g-GA and CS-g-PA treatments could delay the protein oxidation by keeping a higher SH level and Ca²⁺ -ATPase activity. The CS copolymers treatment could also extend the shelf life for another 6 days compared with that of CK. As a result, CS copolymers can be employed in a promising method for the preservation of sea bass. PRACTICAL APPLICATION: The incorporation of gallic acid and protocatechuic acid onto chitosan (CS-g-GA and CS-g-PA) showed superior antioxidant and antimicrobial activities when applied on sea bass. The CS-g-GA and CS-g-PA coatings could maintain the quality and freshness of refrigerated sea bass. Additionally, this research could provide a theoretical basis for the application of graft copolymers on the preservation of aquatic products.

Immediate clinical and microbiological evaluation of the effectiveness of 0.5% versus 3% sodium hypochlorite in root canal treatment: A quasi-randomized controlled trial

AIM

To test the hypothesis that in the daily routine of a specialist clinic in endodontics that irrigation during root canal preparation with 3.0% NaOCl will result in fewer postoperative samples with cultivable bacteria than irrigation with 0.5% buffered NaOCl but, at the same time, will not result in a higher frequency of postoperative pain nor swelling.

METHODOLOGY

Two hundred ninety-eight patients were enrolled in the study and were randomly assigned into two groups - 0.5% NaOCl and 3% NaOCl. All endodontic diagnoses were included. Root canal treatment was performed, and bacterial sampling was carried out prior to root filling. The patients were requested to complete a form regarding pain and swelling seven days postoperatively. Fisher's exact test, Mann-Whitney U-test, Mantel-Haenszel chi-squared and the chi-squared test with a significance level of P < 0.05 were used for statistical analysis. Multivariable logistic regression was used to adjust for confounders.

RESULTS

In the 0.5% NaOCl group, 18 (13.4%) of the root canal samples were positive; in the 3% NaOCl group, the corresponding number was 24 (18.6%). The mean difference of -5.2% (95% CI: -14.8 to 4.4) was not significant (P = 0.33). In the 0.5% NaOCl group, 57 (53.8%) patients reported some pain; in the 3% group, the corresponding number was 56 (53.3%). The mean difference of 0.4 (95% CI: -14.0 to 14.8) was not significant (P = 1.0). In the 0.5% NaOCl group, 5 (5.1%) patients reported swelling; in the 3% NaOCl group, the corresponding number was 18 (17.8%). The mean difference was 12.7 (95% CI: 3.1-22.4), which was significant (P = 0.0084).

CONCLUSIONS

The difference in the concentration of NaOCl (0.5% vs 3%) had no significant impact on the number of positive cultures and did not influence either the frequency or the magnitude of postoperative pain. A significantly higher incidence of postoperative swelling was recorded for patients who received a greater concentration of NaOCl (3%).

Clinical Spectrum of Pediatric Tuberculosis: A Microbiological Correlation from a Tertiary Care Center

AIM AND OBJECTIVES

The paucibacillary nature of pediatric tuberculosis (TB) makes diagnosis difficult. The aim of the study was to correlate the clinical spectrum of pediatric TB with microbiological diagnosis.

MATERIALS AND METHODS

Specimens from clinically suspected pediatric TB cases were subjected to Ziehl-Neelsen staining, culture on Lowenstein-Jensen medium and cartridge-based nucleic acid amplification test (CB-NAAT) for TB.

RESULTS

Pulmonary TB was the predominant form affecting 36 of 62 (58%) patients. Tubercular meningitis was the commonest form of extrapulmonary type and affected 13 of 26 (50%) children. Microbiological diagnosis by any of the above methods could be established in 35 (56.45%) cases. While 33 of 36 (92%) patients diagnosed with pulmonary TB had radiological findings, of which only 25 (76%) could be microbiologically confirmed, only 24 of 31 (77%) patients with extrapulmonary symptoms had radiological evidence and microbiological confirmation could be achieved in 4 (17%) of these.

CONCLUSION

An integrated approach of diagnosis, including clinical-radiological, microbiological and immunological evidence should be stressed on.

Standards Compliance and Health Implications of Bottled Water in Malawi

Many people around the globe prefer bottled water especially in developing countries, where tap water is not drinkable. This study investigated the quality of bottled drinking water sold in Lilongwe city, Malawi. Compliance with Malawi Standards (MS) 560 (2004) for natural mineral water, MS 699 (2004) for bottled water and the World Health Organisation guidelines for drinking water were examined. Bottled water from different 12 brands was purchased from local stores and analysed for its pH, total dissolved solids (TDS), EC, turbidity, Ca, Mg, Na, K, Fe, NO₃⁻, Cl⁻, F⁻, SO₄²⁻, hardness, alkalinity, and Escherichia coli. A Hierarchical Cluster Analysis (HCA) resulted in two clusters in which most of the brands (92%, n = 12) belonged to one group. The two clusters and significant differences (ANOVA p < 0.05) in chemical compositions among the brands were attributed to the variations in the water source and the treatment processes. The results showed that 10 brands did not comply with the MS 699 (2004) turbidity standard (1 NTU) and the pH of one of the brands was below the minimum MS 699 (2004) standard of 6.50. This research showed that 12 brands had bottle labelling errors and discrepancies in chemical composition. The article highlighted the need for a strict inspection from the responsible governmental ministry to improve water quality and to adjust water bottles’ labels according to water characteristics.

Strategies for the screening of antibiotic residues in eggs: comparison of the validation of the classical microbiological method with an immunobiosensor method

Efficient screening methods are needed to control antibiotic residues in eggs. A microbiological kit (Explorer® 2.0 test (Zeu Inmunotech, Spain)) and an immunobiosensor kit (Microarray II (AM® II) on Evidence Investigator™ system (Randox, UK)) have been evaluated and validated for screening of antibiotic residues in eggs, according to the European decision EC/2002/657 and to the European guideline for the validation of screening methods. The e-reader™ system, a new automatic incubator/reading system, was coupled to the Explorer 2.0 test. The AM II kit can detect residues of six different families of antibiotics in different matrices including eggs. For both tests, a different liquid/liquid extraction of eggs had to be developed. Specificities of the Explorer 2.0 and AM II kit were equal to 8% and 0% respectively. The detection capabilities were determined for 19 antibiotics, with representatives from different families, for Explorer 2.0 and 12 antibiotics for the AM II kit. For the nine antibiotics having a maximum residue limit (MRL) in eggs, the detection capabilities CCβ of Explorer 2.0 were below the MRL for four antibiotics, equal to the MRL for two antibiotics and between 1 and 1.5 MRLs for the three remaining antibiotics (tetracyclines). For the antibiotics from other families, the detection capabilities were low for beta-lactams and sulfonamides and satisfactory for dihydrostreptomycin (DHS) and fluoroquinolones, which are usually difficult to detect with microbiological tests. The CCβ values of the AM II kit were much lower than the respective MRLs for three detected antibiotics (tetracycline, oxytetracycline, tylosin). Concerning the nine other antibiotics, the detection capabilities determined were low. The highest CCβ was obtained for streptomycin (100 µg kg^-1).

Microbiological Zoonotic Emerging Risks, Transmitted Between Livestock Animals and Humans (2007-2015)

As part of the Emerging Risk Identification (ERI) activities of the European Food Safety Authority (EFSA), a literature search was conducted to identify the microbiological agents transmitted between livestock animals and humans that have been suggested as having emerged between 2007 and 2015 in peer-reviewed scientific literature published during the same period (2007-2015). According to the criteria set, the search identified seven such zoonotic agents, namely West Nile Fever virus, Rift Valley Fever virus, Crimean-Congo Haemorrhagic Fever virus, Influenza A H1N1 virus, Coxiella burnetii, Streptococcus suis and livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398. An explanation of the agents' consideration as emerging risks is provided. The experience gained from these emergences has shown that the detection of and response to such risks can be achieved faster and more successfully within a multidisciplinary, collaborative context at the field, local, national and international levels.

Storage Stability of Slightly Acidic Electrolyzed Water and Circulating Electrolyzed Water and Their Property Changes after Application

Slightly acidic electrolyzed water (SAEW) has been recognized as an effective bactericidal agent with free chlorine, but its limitations include its instability and its great dependence on equipment. Newly developed circulating electrolyzed water (CEW) with a higher available chlorine concentration (ACC) could successfully overcome these limitations. In this study, SAEW (ACC of 20 mg/L), CEW1 (ACC of 200 mg/L), and CEW2 (ACC of 20 mg/L) were evaluated for changes in properties (pH, oxidization reduction potential [ORP], and ACC) during storage in open or closed glass bottles under light or dark conditions at room temperature (approximately 20 °C) and after washing pork and lettuce. Additionally, the washed pork and lettuce were evaluated for total viable counts, pH and general appearance. The results showed that CEW1 with a higher ACC has better stability than SAEW with a lower ACC for the storage and washing experiments, and CEW still remained stable after dilution with distilled water. The property indices of EW were greatly affected for the pork-washing experiments compared with the lettuce-washing experiments, probably due to the existence of alkaline and organic materials on the surface of pork. Furthermore, EWs were more effective for inactivating microbes in lettuce than in pork, while there was no significant difference in tissue pH and the general appearance of pork and lettuce. These findings indicated that CEW with a higher ACC shows potential for reducing foodborne pathogens on pork and lettuce without effects on their physicochemical characteristics, and it can be applied in a diluted form.

Physico-chemical, sensory, and microbiological assessments of wheat-based biscuit improved with beniseed and unripe plantain

The consumption of cereal foods such as biscuit has become very popular globally. Partial replacement of wheat flour with beniseed and unripe plantain flours rich in protein, vitamins, and minerals will increase nutrient, diversify utilization of beniseed and unripe plantain, and increase biscuit variety. Wheat composite biscuit was produced from wheat, beniseed, and unripe plantain flours. The composite flour was mixed in the proportion of 100:0:0, 80:10:10, 70:20:10, 60:30:10, and 50:40:10% of wheat, beniseed, and unripe plantain, respectively. The physical, sensory, chemical, and microbial properties of the biscuits were determined. The physical properties ranged from 6.80 g to 8.30 g for weight, spread ratio 6.93–7.38, and break strength 500–690 g. There was no significant difference (P < 0.05) in taste, crispness, flavor and texture of the biscuits while significant differences (P < 0.05) existed in color and overall acceptability. The proximate composition of the biscuits ranged from 1.84% to 2.55% for moisture, protein 8.03–9.26%, fat 30.07–35.81%, ash 2.94–3.68%, crude fiber 0.47–0.80%, carbohydrate 48.74–55.96%, and energy 526.53–554.21 kcal/100 g. The microbial count of the best biscuit after 20 days of storage was 4.0 × 10³ cfu/g for bacteria and mould contained 5.0 × 10⁴ cfu/g. This study forms a basis for new product development for the biscuit food industry.

Computational fluid dynamics approaches in quality and hygienic production of semisolid low-moisture foods: a review of critical factors

Low-moisture foods have been responsible for a number of salmonellosis outbreaks worldwide over the last few decades, with cross contamination from contaminated equipment being the most predominant source. To date, actions have been focused on stringent hygienic practices prior to production, namely periodical sanitization of the processing equipment and lines. Not only does optimum sanitization require in-depth knowledge on the type and source of contaminants, but also the heat resistance of microorganisms is unique and often dependent on the heat transfer characteristics of the low-moisture foods. Rheological properties, including viscosity, degree of turbulence, and flow characteristics (for example, Newtonian or non-Newtonian) of both liquid and semisolid foods are critical factors impacting the flow behavior that consequently interferes heat transfer and related control elements. The demand for progressively more accurate prediction of complex fluid phenomena has called for the employment of computational fluid dynamics (CFD) to model mass and heat transfer during processing of various food products, ranging from drying to baking. With the aim of improving the quality and safety of low-moisture foods, this article critically reviewed the published literature concerning microbial survival in semisolid low-moisture foods, including chocolate, honey, and peanut butter. Critical rheological properties and state-of-the-art CFD application relevant to quality production of those products were also addressed. It is anticipated that adequate prediction of specific transport properties during optimum sanitization through CFD could be used to solve current and future food safety challenges.

Validation of the Explorer® 2.0 test coupled to e-Reader® for the screening of antimicrobials in muscle from different animal species

The Explorer(®) 2.0 tube test is a microbial inhibition test for the screening of antimicrobial residues in food samples. The new e-Reader(®) device coupled to Explorer(®) 2.0 operates by incubation at a selected temperature, determination of the endpoint of the assay and interpretation to generate results. This system was validated for muscle samples according to the European Commission Decision 2002/657/EC. Sensitivity towards 25 substances from several groups of antimicrobials was investigated in a first step. Detection capabilities for six substances representing the six major antimicrobial groups were also determined in bovine muscle. The detection capabilities for amoxicillin (10 µg l(-1)), cefalexin (200 µg l(-1)), doxycyclin (100 µg l(-1)), sulfamethazine (100 µg l(-1)), tylosin (100 µg l(-1)) and neomycin (200 µg l(-1)) were in all cases at or below the maximum residue limit (MRL). Specificity and applicability of the test were demonstrated with muscle samples from four animal species (bovine, porcine, ovine and poultry) and results were found to be satisfactory. Ruggedness was evaluated on negative and spiked samples with sulfamethazine as a representative antimicrobial. Neither false-positives nor false-negatives were detected when varying the sample volume, the time of pre-incubation, the temperature of incubation and the batch of the test. These results prove that Explorer(®) 2.0 coupled to e-Reader(®) is a valuable tool for the screening of a broad range of antimicrobials in muscle. This new methodology simplifies the analysis and increases the accuracy of interpretation of the test results since the endpoint of the assay is automatically determined and results are interpreted objectively.

Simultaneous detection of gastrointestinal pathogens with a multiplex Luminex-based molecular assay in stool samples from diarrhoeic patients

We have evaluated the multiplex molecular method xTAG(®) Gastrointestinal Panel (GPP) for detecting pathogens in stool samples of diarrhoeic patients. We collected 440 samples from 329 patients (male:female ratio of 1.2:1), including 102 immunosuppressed adults, 50 immunosuppressed children, 56 children attending the neonatal unit and 121 children attending the emergency unit. Of these, 176 samples from 162 patients were xTAG(®) GPP positive (102 viruses, 61 bacteria and 13 parasites) and the assay was more sensitive than the conventional test for detecting rotavirus (p <0.01), noroviruses (p <0.0001), Salmonella spp. (p <0.001), Campylobacter spp. (p <0.001) and toxigenic Clostridium difficile (p 0.005). The predominant pathogens were viruses (23.2%), with rotavirus (15.9%) being the most common. Bacterial agents were detected in 13.9%; the most common was Salmonella spp. (4.8%). Parasites were detected in 2.9%; Cryptosporidium spp. (2%) was the most common. There were 31 co-infections (7% of samples), involving two pathogens in 23 (5.2%) and three pathogens in eight (1.8%) samples. There were 113 (92.6%) positive samples from the children attending the emergency unit, 25 (17%) positive samples from immunosuppressed adults, 22 (25.3%) positive samples from immunosuppressed children and 16 (19%) positive samples from children attending the neonatal unit. The low turnaround time and technical hands-on time make this multiplex technique convenient for routine use. Nevertheless, conventional bacterial culture and parasitological stool examination are still required to detect other pathogens in specific cases and to determine susceptibility to antibiotics.

Microbiological and histopathological aspects of canine pyometra

As pyometra is recognized as one of the main causes of disease and death in the bitch the purposes of this study were to evaluate microbiological and histopathological aspects of canine pyometra and to research the virulence factors of the E. coli isolates identifying possible risks to human health. The microbiological isolation from the intrauterine contents of 100 dogs with pyometra was carried out and the virulence factors in the E. coli strains were identified using PCR method. This study also consisted of the counting of microorganisms colonies forming units in samples of intrauterine content, tests of antimicrobial susceptibility of the E. coli isolates and the histological examination of the uterus. E. coli was the most prevalent microorganism isolated (76.6%) and 120 strains (79.5%) were positive for sfa, 86 (56.9%) were positive for cnf, 87 (57.6%) were positive for pap, 52 (34.4%) were positive for hly, 51 (33.8%) were positive for iuc and 5 (3.3%) were positive for afa genes. One observed more sensitivity of E. coli to norfloxacin, polimixin B, sulphazotrin, chloranfenicol and enrofloxacin. In 42% of the samples of uterine walls where microorganisms were isolated, the sizes of the areas of the inflammatory responses corresponded to 39–56%. Virulence factors were identified in 98.0% of the strains evaluated, demonstrating a high frequency of potentially pathogenic E. coli. It must be considered that dogs are animals that are living in close proximity to man for thousands of years and have an important role in the transmission of E. coli to other animals and to man.