Rapid Detection of β-lactam Antibiotic Residue in Milk Using Biolayer Interferometry

[ Objective] This study aimed to establish a high-sensitivity method for rapid detection of^-lactam antibiotic residue in milk. [Method] Based on bio- layer interferometry technology, ampicillin-BSA conjugate was fixed on the bottom of APS fiber optic biosensor probe through hydrophobic interaction and bound to 40 mn colloidal gold-labeled/3-1actam antibiotic receptor, to detect β-lactam antibiotics in milk. [ Result] The sensitivity of colloidal gold-labeled BLI method was twice as high as that of immunechromatographic test strip in detection of β-1actam antibiotic residue in milk. Colloidal gold-labeled BLI method exhibited good speci- ficity and had no cross-reaction with 1 000 ng/ml aflatoxin M1, gentamicin, kanamycin, streptomycin, tylosin, chloromycetin and melamine. [Condusion] The colloidal gold-labeled BLI method is not suitable for quantitative detection in actual production due to its small quantitative range in detection of β-lactam antibiot- ics, but it is a simple and rapid qualitative detection method that can be used in rapid detection of β-1actam antibiotic residue in milk.

Optimal mode of capillary electrophoresis for the impurity analysis of β-lactam antibiotics

In order to determine the optimal mode of capillary electrophoresis for the impurity control of β-lactam antibiotics, different modes and various electrophoresis conditions for the separation of impurities were compared.The results showed that micellar electrokinetic capillary chromatography（MEKC） was the optimal separation mode for the impurity profiling of β-lactam antibiotics.In MEKC,not only the common R and S isomers,Δ-2 andΔ-3 isomers,and Z and E isomers,but also the impurities of β-lactam antibiotics could be well separated compared with the capillary zone electrophoresis.Therefore,MECK is the first choice for the separation of impurities of β-lactam antibiotics with capillary electrophoresis（CE）.The optimal separation could be achieved in MEKC by optimizing the pH and the concentrations of buffered saline,micelles and organic solvent（methanol） in running buffer.

Simultaneous determination of 14β-lactam antibiotics in cosmetic products by liquid chromatography tandem mass spectrometry method

In this study,a simple and rapid high-performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） method was established and validated to determine the 14β-lactam antibiotics in cosmetic products,including 1（ceftazidime）,2（cefaclor）, 3（cefdinir）,4（ampicillin）,5（cefalexin）,6（ceftezole）,7（cefotaxim）,8（cefradine）,9（cefuroxime）,10（cephazoline）,11 （cefathiamidine）,12（cefoperazone）,13（cafalotin）,14（piperacillin）.

Effectiveness of antibiotic prophylaxis for acute esophageal variceal bleeding in patients with band ligation: A large observational study

BACKGROUND Esophageal variceal bleeding is a severe complication associated with liver cirrhosis and typically necessitates endoscopic hemostasis.The current standard treatment is endoscopic variceal ligation(EVL),and Western guidelines recom-mend antibiotic prophylaxis following hemostasis.However,given the impro-vements in prognosis for variceal bleeding due to advancements in the management of bleeding and treatments of liver cirrhosis and the global concerns regarding the emergence of multidrug-resistant bacteria,there is a need to reassess the use of routine antibiotic prophylaxis after hemostasis.AIM To evaluate the effectiveness of antibiotic prophylaxis in patients treated for EVL.METHODS We conducted a 13-year observational study using the Tokushukai medical database across 46 hospitals.Patients were divided into the prophylaxis group(received antibiotics on admission or the next day)and the non-prophylaxis group(did not receive antibiotics within one day of admission).The primary outcome was composed of 6-wk mortality,4-wk rebleeding,and 4-wk spontaneous bacterial peritonitis(SBP).The secondary outcomes were each individual result and in-hospital mortality.A logistic regression with inverse probability of treatment weighting was used.A subgroup analysis was conducted based on the Child-Pugh classification to determine its influence on the primary outcome measures,while sensitivity analyses for antibiotic type and duration were also performed.RESULTS Among 980 patients,790 were included(prophylaxis:232,non-prophylaxis:558).Most patients were males under the age of 65 years with a median Child-Pugh score of 8.The composite primary outcomes occurred in 11.2%of patients in the prophylaxis group and 9.5%in the non-prophylaxis group.No significant differences in outcomes were observed between the groups(adjusted odds ratio,1.11;95%confidence interval,0.61-1.99;P=0.74).Individual outcomes such as 6-wk mortality,4-wk rebleeding,4-wk onset of SBP,and in-hospital mortality were not significantly different between the groups.The primary outcome did not differ between the Child-Pugh subgroups.Similar results were observed in the sensitivity analyses.CONCLUSION No significant benefit to antibiotic prophylaxis for esophageal variceal bleeding treated with EVL was detected in this study.Global reassessment of routine antibiotic prophylaxis is imperative.

Assessment of the effectiveness of weight-adjusted antibiotic administration,for reduced duration,in surgical prophylaxis of primary hip and knee arthroplasty

BACKGROUND Prophylactic antibiotics have significantly led to a reduction in the risk of postoperative surgical site infections(SSI)in orthopaedic surgery.The aim of using antibiotics for this purpose is to achieve serum and tissue drug levels that exceed,for the duration of the operation,the minimum inhibitory concentration of the likely organisms that are encountered.Prophylactic antibiotics reduce the rate of SSIs in lower limb arthroplasty from between 4%and 8%to between 1%and 3%.Controversy,however,still surrounds the optimal frequency and dosing of antibiotic administration.AIM To evaluate the impact of introduction of a weight-adjusted antibiotic prophylaxis regime,combined with a reduction in the duration of administration of post-operative antibiotics on SSI incidence during the 2 years following primary elective total hip and knee arthroplasty METHODS Following ethical approval,patients undergoing primary total hip arthroplasty(THA)/total knee arthroplasty(TKA)with the old regime(OR)of a preoperative dose[cefazolin 2 g intravenously(IV)],and two subsequent doses(2 h and 8 h),were compared to those after a change to a new regime(NR)of a weight-adjusted preoperative dose(cefazolin 2 g IV for patients<120 kg;cefazolin 3g IV for patients>120 kg)and a post-operative dose at 2 h.The primary outcome in both groups was SSI rates during the 2 years post-operatively.RESULTS A total of n=1273 operations(THA n=534,TKA n=739)were performed in n=1264 patients.There was no statistically significant difference in the rate of deep(OR 0.74%(5/675)vs NR 0.50%(3/598);fishers exact test P=0.72),nor superficial SSIs(OR 2.07%(14/675)vs NR 1.50%(9/598);chi-squared test P=0.44)at 2 years postoperatively.With propensity score weighting and an interrupted time series analysis,there was also no difference in SSI rates between both groups[RR 0.88(95%CI 0.61 to 1.30)P=0.46].CONCLUSION A weight-adjusted regime,with a reduction in number of post-operative doses had no adverse impact on SSI incidence in this population.

Hypericin enhances β-lactam antibiotics activity by inhibiting sarA expression in methicillinresistant Staphylococcus aureus

Bacteremia is a life-threating syndrome often caused by methicillin-resistant Staphylococcus aureus(MRSA).Thus,there is an urgent need to develop novel approaches to successfully treat this infection.Staphylococcal accessory regulator A(SarA),a global virulence regulator,plays a critical role in pathogenesis andβ-lactam antibiotic resistance in Staphylococcus aureus.Hypericin is believed to act as an antibiotic,antidepressant,antiviral and non-specific kinase inhibitor.In the current study,we investigated the impact of hypericin onβ-lactam antibiotics susceptibility and mechanism(s)of its activity.We demonstrated that hypericin significantly decreased the minimum inhibitory concentrations ofβ-lactam antibiotics(e.g.,oxacillin,cefazolin and nafcillin),biofilm formation and fibronectin binding in MRSA strain JE2.In addition,hypericin significantly reduced sarA expression,and subsequently decreased mecAy and virulence-related regulators(e.g.,agr RNAIII)and genes(e.g.,fnbA and hla)expression in the studied MRSA strain.Importantly,the in vitro synergistic effect of hypericin withβ-lactam antibiotic(e.g.,oxacillin)translated into in vivo therapeutic outcome in a murine MRSA bacteremia model.These findings suggest that hypericin plays an important role in abrogation ofβ-lactam resistance againstMRSA through sarA inhibition,and may allow us to repurpose the use ofβ-lactam antibiotics,which are normally ineffective in the treatment of MRSA infections(e.g.,oxacillin).

In vitro and in vivo activity of D-serine in combination with β-lactam antibiotics against methicillin-resistant Staphylococcus aureus

As D-amino acids play important roles in the physiological metabolism of bacteria,combination of D-amino acids with antibiotics may provide synergistic antibacterial activity. The aim of the study was to evaluate in vitro and in vivo activity of D-serine alone and in combination withβ-lactams against methicillin-resistant Staphylococcus aureus(MRSA) strains, and to explore the possible sensitization mechanisms. The activity of D-serine, β-lactams alone and in combinations was evaluated both in vitro by standard MICs, time–kill curves and checkerboard assays, and in vivo by murine systemic infection model as well as neutropenic thigh infection model. An in vitro synergistic effect was demonstrated with the combination of D-serine and β-lactams against MRSA standard and clinical strains.Importantly, the combinations enhanced the therapeutic efficacy in the animal models as compared toβ-lactam alone groups. Initial mechanism study suggested possible revision of D-alanine-D-alanine residue to D-alanine-D-serine in peptidoglycan by adding of D-alanine in the medium, which may cause decreased affinity to PBPs during transpeptidation. In conclusion, D-serine had synergistic activity in combination with β-lactams against MRSA strains both in vitro and in vivo. Considering the relatively good safety of D-serine alone or in combination with β-lactams, D-serine is worth following up as new anti-MRSA infection strategies.

The Mechanism of Resistance of Pseudomonas Aeruginosa toβ-lactam Antibiotics and Clinical Significance

To study the resistant mechanism and clinical significance of pseudomonas aeruginosa toβ- lactam antibiotics,the outer mem brane permeability rate of30 P.aeruginosa strains to5 β- lactam antibiotics was m easured and their production ofβ- lactamase and theβ- lactam ase genes they carried detected. Furthermore,the relationship between the perm eability,β- lactam ase and the clinical effects ofβ- lactam antibiotics was observed. By using 1 4C- penicillin and liquid- scintillant isotope assay,the affinity of penicillin binding proteins(PBPs) was m easured and their roles in the resistant m echanism studied.Itwas revealed thatthe perm eability rate was higher in sensitive strains than in resistantones(P<0 .0 5 ) .All strains harbored1- 4 β- lactamase genes and produced β- lactam ase.Higher permeability rate and higher degree of stability toβ- lactamase indicated better clinical therapeutic effects. The affinity of PBPs changed little without regard to the perm eability andβ- lactam ase. These results suggested that the permeability of outer mem brane andβ- lacta- mase,but not PBPs,played im portant roles in the resistant mechanism of P. aeruginosa toβ- lac- tam antibiotics and affected the clinical therapeutic effectiveness of som e patients.

Antibiotic Resistance Profile of Salmonella Strains Isolated at the National Clinical Biology and Public Health Laboratory in Bangui, Central African Republic

In Africa, each year, there are estimated to be more than 91 million cases of salmonellosis and 137,000 cases of death. The problem of antibiotic resistance in Salmonella strains is a threat to public health. The objective of this study is to evaluate the antibiotic resistance profile of Salmonella strains isolated in biological products analyzed at the National Laboratory of Clinical Biology and Public Health (NLCBPH) in Bangui. This is, therefore, a cross-sectional study with a descriptive aim, running from January to December 2022. It focused on the strains of Salmonella isolated and identified in stools, urines, and blood samples. For each strain of Salmonella isolated, an antibiogram was carried out following the recommendations of the French Society of Microbiology (CASFM, 2022). A total of 93 strains of Salmonella have been recorded. The age group 0 - 9 years was 29% and that of >50 years was 11%. The median age of patients was 30 years with a minimum of 1 and a maximum of 78 years. The female gender was more represented at 52.69% than the male gender at 47.31%, i.e. a sex ratio of 0.89 (M/F). Salmonella strains were much more isolated in stools at 62% followed by urines at 29% and blood at 6%. Salmonella arizonae strains were more represented with 52%. Salmonella strains have a resistance rate to Tetracycline of 62.37% followed by Penicillins of 50%. The rate of multi-antibiotic resistance of the Salmonella strains isolated represented 48.38%. Salmonella spp. strains were multi-resistant at 58.69% followed by Salmonella arizonae strains at 47.91%. There is a significant association between the different families of antibiotics and Salmonella strains (p < 0.05). According to the results obtained, Penicillins, Phenicoles, and Cyclins had a high rate of resistance on Salmonella strains. No strain-producing Broad Spectrum Beta-lactamase has been isolated. Salmonella strains represent a zoonotic health danger, constitute a public health problem and remain a current subject. This germ is resistant to the antibiotics used. It is, therefore, essential to emphasize monitoring the resistance of these germs in the Central African Republic (CAR) to improve the health of the population.

Integration of antibody-antigen and receptor-ligand reactions to establish a gold strip biosensor for detection of 33 β-lactam antibiotics

A novel lateral flow immunoassay biosensor,combining the receptor-ligand reaction and antigen-antibody reaction was developed for the detection of β-lactam antibiotics in milk. The receptor protein, the carboxy-terminal domain of β-lactam sensor-transducer mutant from Bacillus.licheniformis, served as the recognition element. Colloidal gold(CG)-labelled receptor antibody-receptor ternary complex was applied as a signal transducer probe. The presence ofβ-lactams was identified through a color change in the test zone, where the reaction between the complex of CG/antireceptor antibody/receptor and β-lactam antigen on the test line could be inhibited by β-lactam residues in the sample,thus leading to a reduction in color signal. Based on the indirect labeling of the receptor with an antibody as a linker, the ability to detect 33 β-lactams was below or near the corresponding maximum residue limit. The proposed lateral flow immunoassay biosensor appears to be an excellent field-based screening tool for the qualitative screening of β-lactams in milk.

UV-Based Advanced Oxidation Processes for Antibiotic Resistance Control: Efficiency, Influencing Factors, and Energy Consumption

Antibiotic resistant bacteria(ARB)with antibiotic resistance genes(ARGs)can reduce or eliminate the effectiveness of antibiotics and thus threaten human health.The United Nations Environment Programme considers antibiotic resistance the first of six emerging issues of concern.Advanced oxidation processes(AOPs)that combine ultraviolet(UV)irradiation and chemical oxidation(primarily chlorine,hydrogen peroxide,and persulfate)have attracted increasing interest as advanced water and wastewater treatment technologies.These integrated technologies have been reported to significantly elevate the efficiencies of ARB inactivation and ARG degradation compared with direct UV irradiation or chemical oxidation alone due to the generation of multiple reactive species.In this study,the performance and underlying mechanisms of UV/chlorine,UV/hydrogen peroxide,and UV/persulfate processes for controlling ARB and ARGs were reviewed based on recent studies.Factors affecting the process-specific efficiency in controlling ARB and ARGs were discussed,including biotic factors,oxidant dose,UV fluence,pH,and water matrix properties.In addition,the cost-effectiveness of the UV-based AOPs was evaluated using the concept of electrical energy per order.The UV/chlorine process exhibited a higher efficiency with lower energy consumption than other UV-based AOPs in the wastewater matrix,indicating its potential for ARB inactivation and ARG degradation in wastewater treatment.Further studies are required to address the trade-off between toxic byproduct formation and the energy efficiency of the UV/chlorine process in real wastewater to facilitate its optimization and application in the control of ARB and ARGs.

Nature’s Pharmacy under Siege: Investigating Antibiotic Resistance Pattern in Endophytic Bacteria of Medicinal Plants

Antibiotic resistance poses a significant global health threat, necessitating a thorough understanding of its prevalence in various ecological contexts. Medicinal plants, renowned for their therapeutic properties, host endophytic bacteria that produce bioactive compounds. Understanding antibiotic resistance dynamics in these bacteria is vital for human health and antibiotic efficacy preservation. In this study, we investigated antibiotic resistance profiles in endophytic bacteria from five medicinal plants: Thankuni, Neem, Aparajita, Joba, and Snake plant. We isolated and characterized 113 endophytic bacteria, with varying resistance patterns observed against multiple antibiotics. Notably, 53 strains were multidrug-resistant (MDR), with 14 exhibiting extensive drug resistance (XDR). Thankuni-associated bacteria displayed 44% MDR and 11% XDR, while Neem-associated bacteria showed higher resistance (60% MDR, 13% XDR). Aparajita-associated bacteria had lower resistance (22% MDR, 6% XDR), whereas Joba-associated bacteria exhibited substantial resistance (54% MDR, 14% XDR). Snake plant-associated bacteria showed 7% MDR and 4% XDR. Genus-specific distribution revealed Bacillus (47%), Staphylococcus (21%), and Klebsiella (11%) as major contributors to MDR. Our findings highlight diverse drug resistance patterns among plant-associated bacteria and underscore the complexity of antibiotic resistance dynamics in diverse plant environments. Identification of XDR strains emphasizes the severity of the antibiotic resistance problem, warranting further investigation into contributing factors.

Detection of Beta-Lactamase and Extended-Spectrum Beta-Lactamase of Pathogens Isolated from Pig and Chicken and Their Antibiotic Susceptibility Test

The antibacterial activity of beta-lactam antibiotics or their combinations with inhibitor sulbactum against non-lactamase- producing strains, lactamase-producing and ESBLs-producing isolates was evaluated with twofold dilution method after pathogens isolated from pigs and chickens were detected, respectively, for beta-lactamase and extended-spectrum beta- lactamases （ESBLs）, The results revealed that most of 43 clinically isolated strains could produce beta-lactamase and 3 strains of shigella isolated from chicken samples produced ESBLs. All of 30 lactamase-producing strains isolated and only one of 16 non-lactamase-producing strains were resistant to amoxicillin and ampicillin. MICs of ampicillin against lactamaseproducing isolates decreased 10-40 and 10-20 times respectively, when it was conbined with sulbactam at ration of 1：2 and 1：4. All clinical isolates were susceptible to third-generation cephalosporins. The MICs of third-generation cephalosporins against lactamase-producing isolates did not change when they were conbined with sulbactam. MICs of ceftiofur and ceftriaxone against ESBLs-producing isolates decreased 2-4 times when they were conbined with sulbactam.

In Situ Raman Monitoring of Trace Antibiotics in Different Harsh Water Environments

In situ surface-enhanced Raman scattering(SERS)is a widely used operando analytical technique,while facing numerous complex factors in applications under aqueous environment,such as low detection sensitivity,poor anti-interference capability,etc.,resulting in unreliable detectability.To address these issues,herein a new hydrophobic SERS strategy has been attempted.By comprehensively designing and researching a SERS-active structure of superhydrophobic ZnO/Ag nanowires,we demonstrate that hydrophobicity can not only draw analytes from water onto substrate,but also adjust"hottest spot"from the bottom of the nanowires to the top.As a result,the structure can simultaneously concentrate the dispersed molecules in water and the enhanced electric field in structure into a same zone,while perfecting its own anti-interference ability.The underwater in situ analytical enhancement factor of this platform is as high as 1.67×10^(11),and the operando limited of detection for metronidazole(MNZ)reaches to 10^(-9)M.Most importantly,we also successfully generalized this structure to various real in situ detection scenarios,including on-site detection of MNZ in corrosive urine,real-time warning of wrong dose of MNZ during intravenous therapy,in situ monitoring of MNZ in flowing wastewater with particulate interference,etc.,demonstrating the great application potential of this hydrophobic platform.This work realizes a synergistic promotion for in situ SERS performance under aqueous environment,and also provides a novel view for improving other in situ analytical techniques.

Urinary Tract Infection in Pediatric Emergency Department of Mohamed VI Hospital in Marrakech: Epidemiological Profile and Antibiotic Resistance

Background: Urinary tract infection (UTI) is one of the most frequent bacterial infections in pediatrics. The aim of our work was to establish the epidemiological and bacteriological profile of UTIs in children and then to study the sensitivity of the bacterial strains isolated to antibiotics. Materials and methods: This is a retrospective descriptive study over 3 years (2019-2022), including all cytobacteriological examination of urine (CBEU), performed in children aged 3 months to 14 years, admitted and treated for UTI, in the pediatric emergency department of Mohamed VI University Hospital. Results: A total of 239 children were included in our study. The mean age was 26 months. The sex ratio was 1.08. Escherichia coli was the most isolated bacterial strain in 79% of samples. The tested strains showed a high level of sensitivity to susceptibility rate toward amikacin (91%) and ciprofloxacin (100%) and whereas the level of resistance was high to the most current recommended antibiotics, mainly beta-lactams. Management was based, in severe forms of pyelonephritis, dual antibiotic therapy based on Third-generation cephalosporins combined with gentamycin. Favorable outcome was noted in 94% of children. Conclusion: Awareness-raising on the proper use of antibiotics, issuing national recommendations for the treatment of urinary tract infections in order to standardize therapeutic regimens is strongly recommended. Effective control of these infections requires a global prevention strategy that implies close collaboration between epidemiologists, clinicians, bacteriologists, hygienists and the health care team.

Evaluation of Antibiotic Prescribing in the Pediatric Department of Gabriel TouréTeaching Hospital, Bamako, Mali

Objectives: The main objective was to evaluate antibiotic prescribing in the Department of Pediatrics at Gabriel Touré teaching hospital. Methods: This was a prospective descriptive study conducted from September 1 to November 31, 2018, in the Department of Pediatrics at Gabriel Touré teaching hospital. All children aged 0 to 15 years hospitalized for any pathology during the study period and having received at least one antibiotic had been included. Results: We collected 445 children’s records out of 1032 admissions during the study period, representing a hospital frequency of 43.1%. The sex ratio was 1.3%. The 2 - 5 age group accounted for 48.1%. Fever was the reason for consultation in 45.6% of cases. Patients’ general condition was altered in 60% of cases. The fathers were blue-collar workers in 65.4% and the mothers housewives in 85%, and had no education in 42.9% and 64.5% respectively. Hepatomegaly was present in 18.2%, splenomegaly in 9.6% and peripheral adenopathy in 3.1%. The site of infection was pulmonary in 37.6% and ENT in 9.2%. Bacterial infection was assumed on admission in 54% of cases, and meningitis in 57.7%. The discharge diagnosis was malaria in 54.6%, severe acute malnutrition in 18.6% and meningitis in 6.7%. The death rate was 3.8%. Neutrophilic leukocytosis was present in 47.3% of patients. CRP was positive in 85% of patients. Blood cultures taken in 27.6% of patients were positive in 5. CSF analysis in 30% of patients showed elevated leukocytes in 6.5%. No cultures were positive. Antibiotic prescription was justified by infectious hypotheses in 43.1% of patients. β-lactam antibiotics were prescribed in 98.6%. Antibiotic therapy was not adapted to national/international recommendations in 68.3% of cases, and was not justified in 16.3% of cases on D5 of hospitalization. Conclusion: Antibiotic use was justified in more than half of patients, but remained inadequate in almost two-thirds of cases, in line with national and international recommendations.

Five-year analysis of isolated pathogens and antibiotic resistance of ocular infections from two large tertiary comprehensive hospitals in east China

AIM:To analyze the spectrum of isolated pathogens and antibiotic resistance for ocular infections within 5y at two tertiary hospitals in east China.METHODS:Ocular specimen data were collected from January 2019 to October 2023.The pathogen spectrum and positive culture rate for different infection location,such as keratitis,endophthalmitis,and periocular infections,along with antibiotic resistance were analyzed.RESULTS:We included 2727 specimens,including 827(30.33%)positive cultures.A total of 871 strains were isolated,530(60.85%)bacterial and 341(39.15%)fungal strains were isolated.Gram-positive cocci(GPC)were the most common ocular pathogens.The most common bacterial isolates were Staphylococcus epidermidis(25.03%),Staphylococcus aureus(7.46%),Streptococcus pneumoniae(4.59%),Corynebacterium macginleyi(3.44%),and Pseudomonas aeruginosa(3.33%).The most common fungal genera were Fusarium spp.(12.74%),Aspergillus spp.(6.54%),and Scedosporium spp.(5.74%).Staphylococcus epidermidis strains showed more than 50%resistance to fluoroquinolones.Streptococcus pneumoniae and Corynebacterium macginleyi showed more than 90%resistance to erythromycin.The percentage of bacteria showing multidrug resistance(MDR)significantly decreased(χ^(2)=17.44,P=0.002).CONCLUSION:GPC are the most common ocular pathogens.Corynebacterium macginleyi,as the fourth common bacterium,may currently be the local microbiological feature of east China.Fusarium spp.is the most common fungus.More than 50%of the GPC are resistant to fluoroquinolones,penicillins,and macrolides.However,the proportion of MDR strains has been reduced over time.

Prescription of Antibiotics in Oral-Dental Practice: Case of the Dental Practice at the Coyah Prefectoral Hospital in the Republic of Guinea 2019-2020

Introduction: Antibiotics are medications that have the property of destroying bacteria or preventing their proliferation. The aim of this study is to evaluate antibiotic prescriptions in oral practice: case of the dental office of the Coyah prefectural hospital. Methods: This is a descriptive cross-sectional study which took place from August 2019 to January 2020 inclusive, i.e. a duration of six (6) months, during which 400 patients were identified. Results: Our results revealed a frequency of 70% of antibiotic prescriptions. The 16 - 25-year-old age group was the most dismayed, at 47.25% and with an average age of 27.78 years. Men represent 55% compared to 45% of women, i.e. sex ratio of 1.22. Pulp gangrene was the most common pathology in 55% of cases. The most prescribed family was Betalactamine or 61.71% and the most represented molecules were Amoxicillin with 56.10% followed by Metronidazole or 34.16%. And the favorable prognosis was observed in 99% of cases. Conclusion: Prescription should always be based on the benefit-risk ratio. This prescription by practitioners aims to prevent or eradicate infections and pain in order to obtain a good therapeutic result.

Antibiotic Resistance Profile of Serotypes of Streptococcus pneumoniae Strains in Bangui, from 2017 to 2022: Case of Serotype 1

Goals: The aim of this study was to determine the antibiotic resistance profile of serotypes of Streptococcus pneumoniae strains circulating in Bangui. Methodology: A prospective and analytical analysis was carried out at the National Laboratory of Clinical Biology and Public Health from 2017 to 2022. The strains came from our study on the contribution to the study of antibiotic sensitivity of Streptococcus pneumoniae strains. The multiplex PCR test was used for its cost-effectiveness in terms of amplifiers which can be purified in order to be sequenced. It also makes it possible to detect several germs as well as their serotypes. For a PCR reaction, several elements are involved in the reaction medium or Master Mix. These are the desoxyribonucleotides (dNTPs), the magnesium ions (MgCl2) and the primers. A set of 14 primers divided into 3 classes were used. Class 1 primers served as an internal control by targeting the cpsA gene. It is a highly conserved gene found in capsular loci characterized to date. The primers of the second class were used to target specific serotypes by specific reactions (out of six possibilities). The group reaction was carried out using the primers of the third class in order to carry out an initial screening of the samples and to classify the pneumococcal isolates. Related serotypes were grouped based on the amplification of common genes. Using the technique of electrophoresis on agarose gel and an ultraviolet radiation device, the migration bands are then visualized and analyzed. The data collected had been entered into Excel 2010 and analyzed with Epi info 7. The exact Fischer chi2 test at the 5% threshold, the relative risk and its 95% confidence interval were used to compare the proportions and determine the associations. Results: 187 antibiotic-resistant strains of Streptococcus pneumoniae were collected. The average frequency of serotypes 1, 9A, 4 and untypeable identified were 43.59%, 18.18%, 18.27% and 39.57% respectively. The frequency of serotype 1 was predominant for the age group over five years old with 56.88%. The male sex was predominant with 55.08% for serotype 1. Resistance to penicillin and gentamicin for serotype 1 during this study, for the age group under 5 years old, was 77%. For serotypes 19A and 4, tetracycline resistance was predominant with 20% for the age group under 5 years. The resistance to penicillin and gentamicin of non-typeable serotypes was 33% for the age group under 5 years old. For the age group over 5 years old, resistance to erythromycin predominated at 37%. The distribution of serotypes by sex depending on antibiotic resistance was variable. There was a statistically significant association between identified serotypes and antibiotic resistance (p Conclusion: The study determined serotypes 1, serotypes 19A, serotypes 4 and non-typeable serotypes. These results would be due to the quality of vaccination or poor protection of vaccines.

Antimicrobial Activity of Some Commercial Toothpastes and Antibiotics on Two Oral Pathogenic Bacteria—An in-Vitro Study

Oral health problems such as periodontal diseases, dental caries, and endodontic infections have a significant negative impact on oral health and impose a substantial financial burden on the global population. The prevalence of these issues is increasing due to the buildup of bacterial plaque and the growing resistance of bacteria to antimicrobial treatments. The aims of this study to evaluate the anti-bacterial activity of four types of antibiotics (Amoxicillin, Augmentin, Azithromycin and Metronidazole) and four types of toothpastes (Sensodyne, ipana, denta and cariax Gingival Kin) on two oral pathogenic bacteria (Streptococcus mutans and Staphylococcus epidermidis). Bacterial samples of previously isolated Streptococcus mutans and Staphylococcusepidermidis were used as test organisms and the Kirby-Bauer disc diffusion method was employed to assess the antibacterial efficacy of various antibiotics and evaluate the impact of different toothpastes using a filter paper disc agar measurement technique. Each filter disc was saturated with toothpaste solution in a test tube for approximately 30 to 40 seconds, after which they were placed on Mueller-Hinton broth bacterial cultures in petri dishes. These Petri dishes were then incubated at 37°C for 24 hours, and the clear zone’s diameter (inhibition zone in mm) was subsequently measured and the results were recorded. The results demonstrated that Sensodyne toothpaste and Metronidazole antibiotic were ineffective against both types of bacteria, while Augmentin and Amoxicillin were effective by high diameter inhibition zones of growth against S. mutans and Azithromycine against S. epidermidis. Also Ipana, Denta, and Cariax Gingival Kin toothpastes exhibited a moderate effect against the two bacteria. This study suggests that certain antibiotics and toothpastes can effectively inhibit the growth of harmful oral bacteria, but not all of them are effective.