Kirby-Bauer Method Research Articles

Bacterial Isolates and Antibiotic Susceptibility of Ear Infections in Al-Kindy Teaching Hospital, Baghdad, Iraq

Background: Ear infections can manifest in many forms depending on site of infection whether external, middle or internal ear and the culprit pathogen whether viral, bacterial or fungal. Acute middle ear infections are usually accompanied by aural discharge. Objective: 1. To get an overview on the bacterial pathogens involved in ear infections. 2. To assess the antibiotic resistance of bacterial pathogens. Methods: A cross sectional study conducted in Al-Kindy Teaching Hospital / Baghdad /Iraq. Swabs taken from 225 patients suffering from aural discharge were tested for culture and sensitivity for the duration of two years 2018-2019. Aural discharge is cultured by inoculating it into blood, MacConkey agar, chocolate agars and Sabouraud agar (for fungi). Then the antibiotic susceptibility and resistance is assessed by (Kirby-Bauer Method). Results: Then, by analyzing the percentage of pathogens involved in ear infections we have found that the highest percentage is for Pseudomonas aeruginosa (51%), followed by Staph, aureus (20%), Proteus vulgaris (11%). Discussion: Cefotaxime, which was known to be an efficient antibiotic against pseudomonas previously, has lost its effectiveness. Similarly, gentamycin is no longer effective against E.coli. Conclusion: Choosing the proper antibiotic in any bacterial infection is of tremendous importance. However, reassessment of antibiotic resistance profiles is vital and should be regarded as a routine task on regular intervals.

Antimicrobial Resistance in Pneumococcal Carriage Isolates from Children under 2 Years of Age in Rural Pakistan.

ABSTRACTAntimicrobial resistance is an emerging public health concern. Ten-valent pneumococcal vaccine (PCV10) was introduced in Pakistan’s Expanded Program on Immunization (EPI) in 2012 as a 3 + 0 schedule without catchup. From 2014 to 2018, children <2 years were randomly selected in two rural union councils of Matiari, Pakistan. Nasopharyngeal swabs were collected using standard WHO guidelines by trained staff and processed at Infectious Disease Research Laboratory at The Aga Khan University, Karachi using culture on sheep blood agar and Multiplex PCR methods described by CDC, USA. Pneumococcal isolates were identified by optochin sensitivity and bile solubility tests. Isolates were then tested for antimicrobial susceptibility by standard Kirby-Bauer disk-diffusion method on Mueller-Hinton Agar (MHA) with 5% sheep blood agar as per Clinical & Laboratory Standards Institute (CLSI) recommendations. Of 3140 children enrolled, pneumococcal isolates were detected in 2370 (75%). Vaccine coverage improved from 41% to 68.4%. Out of the 2370 isolates, 88.4%, 37.6% and 25% were resistant to cotrimoxazole, tetracycline and erythromycin, respectively. There was no resistance to penicillin, ceftriaxone, and vancomycin. For erythromycin, resistance increased from 20% in 2014/15 to 30.8% in 2017/18 and for tetracycline it increased from 34.9% to 41.8% both of which were explained by an increase in prevalence of serotype 19A. Pneumococcal isolates were susceptible to penicillin, ceftriaxone, and vancomycin. They were largely resistant to cotrimoxazole and tetracycline. There was an increase in erythromycin and tetracycline resistance attributed to increasing prevalence of serotype 19A. Pneumococcal isolates from carriage and invasive disease should be closely monitored for antimicrobial susceptibility.IMPORTANCE Antimicrobial resistance is an emerging public health concern particularly in low- and middle-income countries where there is poor regulation and easy availability of antibiotics. This is the first study from Pakistan to report antimicrobial resistance patterns of pneumococcus after vaccine introduction in the community. Pakistan was the first South-Asian country to introduce PCV10 in its Expanded Program on Immunization (EPI) in 2012 as a 3 + 0 schedule without catchup. In this study, we describe the PCV10 impact on antimicrobial resistance patterns of pneumococcal nasopharyngeal carriage in children younger than 2 years of age in a rural district in Pakistan after the introduction of the vaccine.

Pet dogs as reservoir of oxacillin and vancomycin-resistant Staphylococcus spp

The aim of this study was to verify the bacterial resistance profile and detect the presence of mecA gene in Staphylococcus spp. isolated from the nasal microbiota of domiciled dogs. For this purpose 100 nasal swabs from 100 domiciled dogs were collected from the central area of the city of Umuarama (PR), along with a questionnaire answered by their owners. After the isolation all Staphylococcus spp. isolates were submitted to the diffusion disc test by the Kirby-Bauer method, and only oxacillin-resistant samples were submitted to the PCR technique to search for the mecA gene and the results were then submitted to statistical analysis to verify possible risk variables. The 100 Staphylococcus spp. and coagulase negative, among which 41 isolates were resistant to oxacillin, no samples were positive for the mecA gene presence, however, 12 resistant to vancomycin were found. It can be concluded that the domiciled dogs are carriers of Staphylococcus spp. multiresistant, being these a possible source of human contamination.

Preparation and Assessment of Antimicrobial Property of Resin Based Composites Impregnated with Proanthocyanidin and Titanium Dioxide

OBJECTIVE: To synthesize three experimental resin based composites (RBCs) out of a commercial preperation (Control) by impregnating into each a fixed weight (0.01%) of titanium dioxide (TiO2) and three different weight % (0.01, 0.02 and 0.03) of proanthocyanidin (PA) and to compare antibacterial property, from the zones of inhibition of streptococcus mutans (S. mutans), of the specimen restorations made in the experimental and control RBCs. METHODOLOGY: In the first phase, Streptococcus mutans were isolated and identified from the oral cavity of patients and identified on the basis of morphogenic appearance of colonies and confirmed through catalase test and microscopic examination. Isolates were then incubated and cultured for sensitivity. Specimens for control and experimental RBCs were made through a metallic mold having 2mm thickness and 5mm diameter for all the 4 groups. Specimen restorations made in the commercial as supplied RBC acted as the control (Group A). Specimen restorations in the Group B, C, and D were made in each of the experimental RBCs modified with 0.01% proanthocyanidin (PA) and 0.01% titanium dioxide (TiO2), 0.02% PA and 0.01% TiO2 and 0.03% PA and 0.01% TiO2. The antimicrobial property of all the specimen restorations in all the groups was evaluated by Bauer-Kirby (Disc Diffusion) method through the formation of zones of inhibition of S. mutans colonies on blood agar plates. Data were computed using SPSS version 21 for descriptive statistics and analyzed using one-way ANOVA with p value 0.05 taken as significant. RESULTS: The range of the zone of inhibition for specimen RBC restorations (N= 12) containing PA and TiO2 was 0.00 for Group A, 10-12mm for Group B, 12-14mm for Group C and 9-10mm for Group D. The mean inhibition zone for the experimental restoration specimens was 11±2mm for Group B, 12.7±1mm for Group C and 9.7±1mm for Group D compared to no inhibition zones (0.00 mm) with the control RBC Group A. The order of the inhibition zones from maximum to minimum was Group C &gt; Group B &gt; Group D &gt; Group A. The differences between the mean values for the control and the experimental RBC restoration specimens were significant (p &lt; 0.000). The specimen restorations in the Group D appeared under cured and could impact on their mechanical properties. CONCLUSION: Irrespective of the mentioned concentrations, impregnating PA and TiO2 rendered the RBC antimicrobial. RBC restorations made with the experimental RBC with 0.02% PA and 0.01% TiO2 proved relatively more effective in terms of antimicrobial effect. KEY WORDS: dental materials, resin based dental restorations, antibacterial resin based composite, proanthocyanidin, titanium dioxide.

Antibiotic Activity of Actinomycetes Isolated from Young Tectona Grandis (L.) Wood and Pith

Actinomycetes are a source for novel bioactive compounds and justify obtaining new species from various sources. Hardwoods such as Tectona grandis (L.) have not been studied for actinomycete isolation. We aim to isolate endophytic actinomycetes from young Tectona grandis wood and pith and screen for antibiotic activity. Five young wood were cut and surface sterilized using ethanol and hypochlorous acid. The wood and pith of each sample are placed in eight plates of Humic acid-vitamin B (HV), Tap water Yeast extract (TWYE), and Yeast Extract Casein Digest (YECD) medium and incubated at 27°C for four weeks. Actinomycetes were isolated from such medium, observed every week, and transferred to an International Streptomyces Project-2 (ISP-2) medium for identification and antibiotic production tested against Staphylococcus aureus, Helicobacter pylori, and Escherichia coli using the Kirby-Bauer method. Seven actinomycetes were isolated from the wood, primarily from YECD and TWYE media, with varying morphological characteristics. One isolate having maroon-colored aerial and vegetative mycelium with grey spores showed moderate antibacterial activity against S. aureus and H. pylori (13.49±1.03 mm and 14.9±0.7 mm, respectively), while two other actinomycetes showed weak activity against these bacteria. However, none of the actinomycetes show any activity against E. coli. Tectona grandis (L.) is a potential source for novel actinomycetes with an antibiotic activity which warrants further exploration

Determination of the direction of action of «EM® PROBIOTIC FOR BEES» against bee dysbacteriosis pathogens in vitro

In many countries around the world, massive declines in bee colonies have been reported as a consequence of the multifactorial effects of exogenous and endogenous factors. The development of opportunistic infections in bees is due to an imbalance of opportunistic pathogenic microflora that colonise the midgut of insects. The problem of dysbacteriosis in various animal species, including bees, is of interest to veterinarians. Therefore, the search for new remedies alternative to antibiotics is a high priority in beekeeping. Probiotic preparations have been proposed as new and safe medicines for the treatment and prevention of dysbacteriosis in human and veterinary medicine. Probiotics are products containing live micro-organisms that are able, in a certain dosage, to influence the macro-organism effectively. The application of such therapeutic additives to insects is preceded by their preliminary in vitro testing. Therefore, the main aim o the study was to determine the direction of action (bacteriostatic, bactericidal, antagonistic) of «EM® PROBIOTIC FOR BEES», diluted with sugar syrup solution and water in different concentrations, against Klebsiella pneumoniae, Klebsiella (Enterobacter) aerogenes bacteria and on mixed microbialas sociation in vitro. An in vitro experiment on the above probiotic agent was carried by diffusion in agar wells (well method) and a modified KirbyBauer method for the beekeeping industry (disk diffusion method). Bacteriostatic, bactericidal and antagonistic effects were determined visually and by measuring diameter of the are aaround the discs and wells. The bacteriostatic effect of probiotic microorganisms against enterobacteriaceae of Klebsiella pneumoniae species was recorded to be maintained at the same level when diluted with 50 % sugar syrup solution in concentrations from 0.5 % to 30 %. «EM® PROBIOTIC FOR BEES» diluted with water had pronounced antagonistic effect against Klebsiella pneumoniae bacteria by diffusion in agar wells method at concentrations of 0.5 % - 75,4±1,04 mm and 1% - 61,2±0,42 mm on the third day of the experiment. By diluting the probiotic with 50% sugar syrup solution, inhibition of the growth of Klebsiella (Enterobacter) aerogenes bacteria was observed in concentrations of up to 50%, ranging from 18,2±0,42 mm to 25,4±0,45 mm (disk diffusion method). Bactericidal effect of «EM® PROBIOTIC FOR BEES» diluted with water against mixed microbial association isolated from bee colonies with signs of intestinal disorders was observed at a concentration of 10% with a diameter of 18,6±0,57 mm by the disk diffusion method. Thus, «EM® PROBIOTIC FOR BEES» has antagonistic, bacteriostatic and bactericidal effects against enterobacteriaceae of bees Klebsiella pneumoniae, Klebsiella (Enterobacter) aerogenes species and agaist mixed microbial associations. The nature of the action of this probiotic depends on the solvent and its concentration, which in turn determines the direction and purpose of its application. Key words: beekeeping, dysbiosis, Klebsiella (Enterobacter) aerogenes, Klebsiella pneumoniae, bactericidal and bacteriostatic effects, antagonistic action.

Biodiversity and antibacterial activity of endophytic fungi isolated from jambu bol (Syzygium malaccense)

Abstract. Hapida Y, Elfita, Widjajanti H, Salni. 2021. Biodiversity and antibacterial activity of endophytic fungi isolated from jambu bol (Syzygium malaccense). Biodiversitas 22: 5668-5677. Infectious diseases caused by pathogenic bacteria are still high. The existence of bacterial resistance to antibiotics makes it necessary to search for new antibacterial substances from plants and microorganisms. Syzygium malaccense (L.) Merr and Perry (Myrtaceae), known as jambu bol, has been used as a traditional medicine in Indonesia and other countries. It is used to treat pathogenic bacterial infections. Therefore, this study aims to determine the diversity of endophytic fungi and their potential as antibacterial compound sources compared to their host plants. Specifically, screening for endophytic fungi that have antibacterial activities is intended. In this study, endophytic fungi were isolated from the leaves, stem bark, and root bark of the host plants. Each isolate was identified morphologically and cultivated in potato dextrose broth (PDB) medium for four weeks. After the incubation period, the liquid culture was extracted with ethyl acetate and evaporated to obtain a concentrated extract. The Kirby-Bauer method was used to evaluate the antibacterial activity of each endophytic fungal extract and the host plant parts extract. The concentration used was 400µg/mL and the antibiotic was used as a positive control (Tetracycline) is 30µg/mL. Seven endophytic fungi were isolated from the leaves (YD1, YD2, YD3, YD4, YD6, YD7, Y2D1), seven from the stem bark (YB1, YB2, YB3, YB4, YB5, Y2B5, and Y2B6 ), and six from the root bark (YA1, YA2, YA3, YA4, YA5, Y2A2). The endophytic fungi were morphologically identified, and the isolates were shown to be dominated by genera from the Ascomycota (e.g., Poaceascoma, Cladorrhinum, Penicillium, Madurella, Phytophthora, Phialemonium, Monascus, Trichoderma, Ramophialophora, Gliocladium, Wiesneriomyces) and the Zygomycota (e.g., Mucor, Mortierella, and Gongronella) phyla. The fungi isolates Y2D1, YB1, and YA4 were shown to have the highest (strong) antibacterial activity equivalent to their hosts in the performed screening. Endophytic fungi have significant and continued antibacterial activities that have been identified molecularly.

1290. Ceftazidime-Avibactam Resistance Report in a Third Level Hospital in Mexico City

BackgroundThe surge of resistant Gram-negative organisms has been worrying infectious disease physicians and physicians in general because of the lack of a large number of antibiotics to which these organisms remain susceptible. Ceftazidime-Avibactam (CAZ-AVI) is a drug approved by the FDA to treat complicated urinary tract infections (cUTI), complicated intra-abdominal infections (cIAIs) in combination with metronidazole, and recently for the treatment of nosocomial pneumonia. Worldwide resistance rates of Enterobacteriaceae to CAZ-AVI have been reported below 2.6%, and 4-8% for Pseudomonas aeruginosa. The FDA, CLSI, and EUCAST assigned the clinical breakpoints of susceptibility: MIC < /=8 mg/liter susceptible, and >/=8mg/liter, resistant. In Mexico, CAZ-AVI was approved in 2018, and its cost is very high compared to other antimicrobials, so its use is limited in very specific cases. The resistance rates to this antibiotic in the Mexican population remain largely unknown. MethodsWe tested 106 specimens for susceptibility to ceftazidime-avibactam using the disk Kirby-Bauer method. The inhibition zone diameter was determined in all cases and we considered the organism susceptible when the inhibition zone diameter was >=21 mm, and resistant with an inhibition zone diameter < = 20 mm. ResultsWe found 5 specimens (4.71%) resistant to ceftazidime-avibactam, corresponding to E. coli (3) and P. aeruginosa (2). Two of these were also resistant to colistin, and 4 to meropenem. All carbapenem-resistant isolates harbored Metallo-beta-lactamases genes, for E. coli was NDM gen, and for P. aeruginosa the VIM gene(GeneXpert® Cepheid). ConclusionThe ceftazidime-avibactam resistance among Gram-negative bacteria in our study is similar to the one reported in other international studies. We need more studies in our population to know the nationwide resistance to this antibiotic. Disclosures All Authors: No reported disclosures

Antibiotic resistance in bacterial communities of the oyster Crassostrea rivularis from different salinity zones in Qinzhou Bay, Beibu Gulf, China

The oyster is one of the most abundantly harvested shellfish in the world. To explore the impact of salinity on antibiotic-resistant bacteria (ARB) and the microbial community associated with farmed oysters, oysters were taken from high-, medium-, and low-salinity zones (labeled HS, MS, and LS, respectively) in Qinzhou Bay of Beibu Gulf, China. ARB were tested with the Kirby–Bauer method. Species of ARB were confirmed by 16 S rDNA analysis. Microbial communities were analyzed by high-throughput sequencing technology. The results indicate that HS-derived ARB (&amp;gt;60%) resisted β-lactams and aminoglycosides and that LS-derived strains resisted macrolide and tetracyclines. All strains resisted 4 or more antibiotics. A total of 542 operational taxonomic units were detected in the samples, with Shewanella, Vibrio, and Endozoicomonas being the dominant genera (&amp;gt;80%), although distributed differently among the different salinity samples. The oyster microbial richness ranked as MS &amp;gt; LS &amp;gt; HS. This study provides an important reference for future efforts to explain factors or mechanisms underlying correlations between ARB, the microbiome, and salinity and thus the potential health of oysters in this region.

Epidemiology and Drug Resistance of Pathogens Isolated from Cerebrospinal Fluids at a Children's Medical Center in Eastern China During 2006-2020.

ObjectiveTo investigate the epidemiology and drug resistance of pathogens isolated from cerebrospinal fluid samples at a children’s medical center in eastern China and provide the basis for anti-infection treatments.MethodsIn all, 307 non-duplicated strains of pathogens were isolated from cerebrospinal fluid samples in the Children’s Hospital of Soochow University from January 2006 to December 2020. Mass spectrometry was used for pathogen identification. The VITEK 2 Compact system and Kirby-Bauer method were applied to determine antimicrobial susceptibility.ResultsAmong the 307 isolates, gram-positive bacteria, gram-negative bacteria and fungi accounted for 60.26%, 34.53%, and 5.21%, respectively. The most prevalent pathogens were Streptococcus pneumoniae (26.06%), Escherichia coli (20.20%) and Streptococcus agalactiae (17.26%). The number of isolates was highest in winter. The most prevalent gram-positive bacterium in children <6 months old was Streptococcus agalactiae, while Streptococcus pneumoniae was the most in children were >6 months old. The drug resistance of gram-positive bacteria, fungi and Haemophilus influenza were not high. In addition, 35 strains of gram-negative bacteria produced extended-spectrum β-lactamases (ESBLs) and 6 strains were identified as multidrug-resistant (MDR) bacteria. These strains showed much higher resistance to the antibiotics than other strains.ConclusionCases of meningitis among children have increased in the past 15 years and MDR bacteria were also identified. The emergence of MDR bacteria is a cause for great concern and requires further investigation.

THE PREPARATION OF VARIOUS TEAR-CONTAINING CREAMS AND INVESTIGATION OF THEIR ANTIBACTERIAL PROPERTIES

In our research, the antibacterial properties of tear which protect our eyes from many infections have been investigated by using Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus haemolyticus and Staphylococcus epidermidis bacteria. In addition, the antibacterial effect of creams in different formulations containing vaseline, also known as petroleum jelly, prepared by mixing olive oil and lemon juice which have been known and used throughout history with tears have been investigated. The antibacterial effect has been investigated measuring the zone of inhibition diameters, also known as the Kirby-Bauer method. It has been determined that all samples showed antibacterial effects except Staphylococcus epidermidis to which only tear was applied. The highest antibacterial activity with tear containing cream (vaseline and olive oil) has been observed for Pseudomonas aeruginosa and Staphylococcus epidermidis bacteria. In addition, tear containing cream (vaseline, olive oil and lemon juice) has shown the highest antibacterial effect against Bacillus subtilis and Staphylococcus haemolyticus bacteria.

Analysis of clinical distribution and drug resistance of klebsiella pneumoniae pulmonary infection in patients with hypertensive intra cerebral hemorrhage after minimally invasive surgery.

ABSTRACTObjectives:To investigate the clinical distribution and drug resistance of Klebsiella pneumoniae pulmonary infection in patients with hypertensive intracerebral hemorrhage after minimally invasive surgery.Methods:A total of 658 patients with hypertensive intracerebral hemorrhage who underwent minimally invasive surgery admitted to the intensive care unit (ICU) and the Department of Neurology of Affiliated Hospital of Hebei University from January 2015 to January 2020 were enrolled and divided into two groups: the observation group and the control group. Three hundred and thirty-three cases with postoperative pulmonary infection were included into the observation group, and 325 cases without postoperative pulmonary infection were divided into the control group. The intubation time, neurological deficiency score and Glasgow coma scale (GCS) of the two groups were analyzed and compared. Automatic microbial identification system was utilized to isolate bacteria from patients in the observation group, identify Klebsiella pneumoniae, and analyze Klebsiella pneumoniae infection, clinical department distribution, and age distribution. The Kirby-Bauer method was adopted to carry out the drug susceptibility test of Klebsiella pneumoniae infection.Results:The intubation time and neurological deficiency score of patients with hypertensive cerebral hemorrhage in the observation group were significantly higher than those in the control group (p<0.05), while the GCS score was significantly lower than that in the control group (p<0.05). A total of 403 strains of pathogenic bacteria were isolated from 325 patients in the observation group, of which 52 strains of Klebsiella pneumoniae were detected in 52 patients with postoperative pulmonary infection, accounting for 12.90%. The detection rates of Klebsiella pneumoniae in ICU and neurology department were 53.85% and 46.15%, respectively. Klebsiella pneumoniae had the highest detection rate (40.38%) in people aged 70 years and above. Moreover, fifty-two strains of Klebsiella pneumoniae showed low drug resistance rate (<20%) to cefoperazone/sulbactam, piperacillin/tazobactam, cefoxitin, imipenem, meropenem, amikacin, ciprofloxacin, and levofloxacin.Conclusion:For patients with hypertensive cerebral hemorrhage who have pulmonary infection after minimally invasive surgery, risk factors causing infection should be identified in time, their Klebsiella pneumoniae infection should be correctly monitored, and antibiotics should be taken rationally to effectively promote the elimination of brain edema in patients and protect the cranial nerve function of patients.

Evaluation of Biofilm Formation and Virulence Genes and Association with Antibiotic Resistance Patterns of Uropathogenic Escherichia coli Strains in Southwestern Iran

Background: Uropathogenic Escherichia coli (UPEC) strains, encoding superficial and secretory virulence factors, can lead to colonization and facilitation of bacterial growth in the host urinary tract, causing Urinary Tract Infection (UTI). Objectives: This study determined the ability of biofilm formation by the Congo red agar method, the presence of virulence genes using the multiplex polymerase chain reaction (PCR) method, and the relationship between biofilm formation and antibiotic resistance patterns and virulence genes in E. coli clinical isolates in Yasuj. Methods: This cross-sectional study was performed on 144 UPEC isolates collected in 2017. Biofilm formation was detected by the Congo red agar phenotypic assay and virulence factors by the multiplex PCR method. Antibiotic resistance tests were performed by the Kirby-Bauer method. Results: Out of 144 isolates of E. coli, 22 (19.4%) isolates showed to be strong biofilm producers, 27 (23.8%) moderate biofilm producers, and 64 (56.3%) weak biofilm producers. A significant relationship was observed between biofilm-producing strains and resistance to ampicillin (P = 0.020) and cotrimoxazole (P = 0.038). The virulence genes in strong biofilm producers included iutA (95%), FimH (93%), ompT (90%), PAI (90%), and TraT (81%) genes. The phylogroup B2 carried the most virulence genes. A significant correlation was observed between E. coli phylogenetic groups and aer (P = 0.019), iroN (P = 0.042), and ompT (P = 0.032) virulence genes. Conclusions: The results of this study showed a high prevalence of virulence genes, and antibiotic-resistant E. coli strains capable of biofilm formation. The results of this study may help elucidate the pathogenesis of UPEC and facilitate better treatment strategies for patients with UTIs in this geographic area.

Molecular Epidemiology of Multidrug-Resistant Uropathogenic Escherichia coli O25b Strains Associated with Complicated Urinary Tract Infection in Children.

Background: Uropathogenic Escherichia coli (UPEC) has increased the incidence of urinary tract infection (UTI). It is the cause of more than 80% of community-acquired cystitis cases and more than 70% of uncomplicated acute pyelonephritis cases. Aim: The present study describes the molecular epidemiology of UPEC O25b clinical strains based on their resistance profiles, virulence genes, and genetic diversity. Methods: Resistance profiles were identified using the Kirby–Bauer method, including the phenotypic production of extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs). The UPEC serogroups, phylogenetic groups, virulence genes, and integrons were determined via multiplex PCR. Genetic diversity was established using pulsed-field gel electrophoresis (PFGE), and sequence type (ST) was determined via multilocus sequence typing (MLST). Results: UPEC strains (n = 126) from hospitalized children with complicated UTIs (cUTIs) were identified as O25b, of which 41.27% were multidrug resistant (MDR) and 15.87% were extensively drug resistant (XDR). The O25b strains harbored the fimH (95.23%), csgA (91.26%), papGII (80.95%), chuA (95.23%), iutD (88.09%), satA (84.92%), and intl1 (47.61%) genes. Moreover, 64.28% were producers of ESBLs and had high genetic diversity. ST131 (63.63%) was associated primarily with phylogenetic group B2, and ST69 (100%) was associated primarily with phylogenetic group D. Conclusion: UPEC O25b/ST131 harbors a wide genetic diversity of virulence and resistance genes, which contribute to cUTIs in pediatrics.

Epidemiological Investigation of Salmonella enterica Isolates in Children with Diarrhea in Chengdu, China

Background: Children with the immature intestinal immune system are prone to Salmonella infection through the fecal-oral route causing diarrhea. Non-typhoid Salmonella (NTS) is difficult to treat and eliminate due to its zoonosis. Salmonella typhi, including typhoid and paratyphoid A, B, and C, only infect humans and cause invasive infectious diseases. Salmonella typhi infection is serious and requires antibiotic treatment. The bacterial resistance caused by conventional antibacterial drugs brings great difficulties to treatment. Objectives: This study aimed to investigate the epidemiology of S. enterica in children with diarrhea in Chengdu, China. Methods: Fresh stool specimens or rectal swabs from 6656 children aged 1 day to 13 years with diarrhea were collected, cultured, identified, and tested for antimicrobial susceptibility. Analytical Profile index 20E was used for biochemical identification, and the Kirby-Bauer method was used for the bacterial sensitivity test. The whole process was conducted in accordance with the fourth edition of the National Clinical Examination procedures, and the drug sensitivity test was conducted in accordance with the Clinical and Laboratory Standards Institute 2020 guidelines. Results: A total of 649 Salmonella strains were isolated from 6656 children with suspected Salmonella infection, among which the isolation rates of NTS and S. typhi were 8.92% and 0.83%, respectively. The infection rate of S. typhimurium was the highest every year (74.88%). Salmonella infections are on the rise, especially typhimurium, Dublin, Typhi, and London. Paratyphi is unstable, presenting a phenomenon of transition and replacement (the male to female ratio:1.12:1). The infection rate was the lowest within 1 day and 6 months (P &lt; 0.05). Salmonella mainly infected children under 3 years of age, and the positive rate was reported as 88.29%. Within June-September, the infection rate of Salmonella was the highest, with a positive rate of 72.73%. The isolated 649 Salmonella strains had good susceptibility to cefotaxime and ciprofloxacin (87.67% and 79.20%, respectively), almost no susceptibility to ampicillin, and a drug resistance rate of 92.91%. Conclusions: The typhoid and paratyphoid vaccines should be considered together, and vaccines should focus on children under 3 years of age. Antibiotics should be rationally selected according to the drug sensitivity test and disease condition.

Bacterial Epidemiology and Antimicrobial Resistance Profiles in Children Reported by the ISPED Program in China, 2016 to 2020.

ABSTRACTThe Infectious Disease Surveillance of Pediatrics (ISPED) program was established in 2015 to monitor and analyze the trends of bacterial epidemiology and antimicrobial resistance (AMR) in children. Clinical bacterial isolates were collected from 11 tertiary care children’s hospitals in China in 2016 to 2020. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer method or automated systems, with interpretation according to the Clinical and Laboratory Standards Institute 2019 breakpoints. A total of 288,377 isolates were collected, and the top 10 predominant bacteria were Escherichia coli, Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Klebsiella pneumoniae, Moraxella catarrhalis, Streptococcus pyogenes, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Acinetobacter baumannii. In 2020, the coronavirus disease 2019 (COVID-19) pandemic year, we observed a significant reduction in the proportion of respiratory tract samples (from 56.9% to 44.0%). A comparable reduction was also seen in the primary bacteria mainly isolated from respiratory tract samples, including S. pneumoniae, H. influenzae, and S. pyogenes. Multidrug-resistant organisms (MDROs) in children were commonly observed and presented higher rates of drug resistance than sensitive strains. The proportions of carbapenem-resistant K. pneumoniae (CRKP), carbapenem-resistant A. baumannii (CRAB), carbapenem-resistant P. aeruginosa (CRPA), and methicillin-resistant S. aureus (MRSA) strains were 19.7%, 46.4%%, 12.8%, and 35.0%, respectively. The proportions of CRKP, CRAB, and CRPA strains all showed decreasing trends between 2015 and 2020. Carbapenem-resistant Enterobacteriaceae (CRE) and CRPA gradually decreased with age, while CRAB showed the opposite trend with age. Both CRE and CRPA pose potential threats to neonates. MDROs show very high levels of AMR and have become an urgent threat to children, suggesting that effective monitoring of AMR and antimicrobial stewardship among children in China are required.IMPORTANCE AMR, especially that involving multidrug-resistant organisms (MDROs), is recognized as a global threat to human health; AMR renders infections increasingly difficult to treat, constituting an enormous economic burden and producing tremendous negative impacts on patient morbidity and mortality rates. There are many surveillance programs in the world to address AMR profiles and MDRO prevalence in humans. However, published studies evaluating the overall AMR rates or MDRO distributions in children are very limited or are of mixed quality. In this study, we showed the bacterial epidemiology and resistance profiles of primary pathogens in Chinese children from 2016 to 2020 for the first time, analyzed MDRO distributions with time and with age, and described MDROs’ potential threats to children, especially low-immunity neonates. Our study will be very useful to guide antiinfection therapy in Chinese children, as well as worldwide pediatric patients.

Antibiotic Resistance Profiles of Pseudomonas aeruginosa Isolates Containing Virulence Genes

Background: A most common opportunistic pathogen, Pseudomonas aeruginosa is present in both humans and animals and responsible for various nosocomial infections and healthcare settings related infections. Different virulence genes like; oprL (membrane lipoprotein L) and toxA (exotoxin A i.e. ETA) in P. aeruginosa, assist in its pathogenicity, toxicity and contribute to high antibiotic resistance. So considering the risk of zoonotic transmission of P. aeruginosa through animal-related foods, this study aimed to monitor the prevalence of oprL and toxA virulence genes and antimicrobial resistance in P. aeruginosa isolates, obtained from animal (Cow’s milk) and human clinical samples. Material and methods: Of the total 120 collected samples for this study, every 60 samples were collected from animals and humans from respective laboratories. Total 76 isolates of P. aeruginosa were isolated and identified by morphological and biochemical tests. The presence of virulence factors like oprL and toxA were evaluated by PCR analysis and antimicrobial resistance was assessed by antibiotic susceptibility test (Kirby-Bauer method). Results: From the total 76, P. aeruginosa isolates obtained from both animal and human isolates, alone presence and coexistence of both toxA and oprL genes in P. aeruginosa isolates; were detected in PCR analysis. PCR analysis results showed in P. aeruginosa isolates, alone distribution of toxA and oprL genes is, 75% and 54.16% in animals, and 84.61% and 80.76% in humans, respectively. The coexistence of both genes was 37.50% and 40.32% in animals and human isolates, along with high antibiotic resistance in most P. aeruginosa isolates. Conclusion: Therefore, this study suggested PCR analysis can be used for fast and specific detection of oprL and toxA genes in P. aeruginosa. Monitoring of these genes can help to prevent the risk of transmission of multi-drug resistant P. aeruginosa, from animals to humans.

The Antibacterial Activity of Red Dragon Fruit Peel (Hylocereus polyrhizus Britton &amp; Rose) Methanolic Fraction Against Staphylococcus epidermidis and Propionibacterium acnes

Acnes can be caused by Propionibacterium acnes and Staphylococcus epidermidis. Red dragon (Hylocereus polyrhizus B &amp; R) fruit peels is one of natural materials which is assumed to possess an antibacterial activity. The purpose of this study was to determine the antibacterial activity of red dragon fruit peels methanol fraction (RDFPMF) against S. epidermidis and P. acne by disc diffusion Kirby-Bauer method. Red dragon fruit peels were maceration in chloroform and fractionation in methanol. Clindamycin 4µg/disk was used as positive control and DMSO 10% was used as negative control. This research showed that the RDFPMF has antibacterial activity against P. acnes which the average of inhibition zones obtained from the concentrations from 100, 50, and 25 mg/mL respectively were 10.5 ± 0.50 mm, 10.0 ± 0.00 mm, and 8.5 ± 0.50 mm. The RDFPMF has no inhibition zone toward S. epidermidis. The red dragon fruit peels methanol fraction has antibacterial activity on P. acnes by disc diffusion method (Kirby-Bauer test).

Diversity of endophytic fungi from the root bark of Syzygium zeylanicum, and the antibacterial activity of fungal extracts, and secondary metabolite

Abstract. Syarifah, Elfita, Widjajanti H, Setiawan A, Kurniawati AR. 2021. Diversity of endophytic fungi from the root bark of Syzygium zeylanicum, and the antibacterial activity of fungal extracts, and secondary metabolite. Biodiversitas 22: 4572-4582. The decoction of the root bark of Syzygium zeylanicum has been used as traditional medicine, such as for treating pathogenic bacterial infections. Endophytic fungi that live in medicinal plant tissues have a high species diversity and biological activities correlate with their host. Therefore, this study aimed to explore the diversity of endophytic fungi from the root bark of S. zeylanicum and to determine the antibacterial activity of endophytic fungi and their secondary metabolites. In this study, we isolate and identify the endophytic fungi from the root bark of S. zeylanicum, continued by screening their antibacterial activity against two Gram-negative bacteria (Escherichia coli InaCCB5 and Salmonella thypi ATCC1048 and two Gram-positive bacteria (Staphylococcus aureus InaCCB4 and Bacillus subtilis InaCCB1204) by the Kirby-Bauer method. The fungal extract with the highest antibacterial activity proceeded with the isolation and determination of the structure of their bioactive compounds. The isolates were morphologically identified. Isolates that showed strong antibacterial activity were identified by molecular identification. Isolation of bioactive compounds was carried out by chromatographic techniques and the determination of the structure of pure chemical compounds was performed by the spectroscopic analysis. In total, there were 8 isolates of endophytic fungi were obtained from the root bark of S. zeylanicum, namely SZR1 – SZR8. SZR2 isolate has the highest antibacterial activity. Molecular identification through phylogenetic analysis showed that SZR2 isolate had high similarity with Penicillium brefeldianum. Isolation of bioactive compounds from SZR2 produced compound 1 in the form of light yellow crystals which showed strong antibacterial activity against S. typhi, E. coli, and B. subtilis with MIC values of 64 g/mL. Compound 1 was identified as p-hydroxybenzaldehyde, which was also obtained in its host. In conclusion, the endophytic fungus Penicillium brefeldianum produces similar secondary metabolites and antibacterial activity as its host plant.

INVESTIGATION ON THE PHENOTYPIC CHARACTERISTICS OF ANTIBIOTIC RESISTANCE AND SOME GENETIC CHARACTERISTICS OF KLEBSIELLA PNEUMONIAE ISOLATES CAUSING INFECTIONS AT HUE UNIVERSITY OF MEDICINE AND PHARMACY HOSPITAL AND KHANH HOA GENERAL HOSPITAL

Objectives: To definite antibiotic-resistant phenotypes of Klebssiella pneumoniae isolated; Identifying some virulence genes and antibiotic resistance genes in strains of Klebssiella pneumoniae isolated from clinical samples collected in infected patients. Methods: We cultured, isolated and identified Klebsiella pneumoniae. Then we definitely the sensitivity to antibiotics of bacteria by disk diffusion (Kirby-Bauer) method, definited the production of ESBL. Considering the proportion of blaNDM-1, blaKPC, blaOXA-48, magA, rmpA genes by multiplex PCR. Results: Klebssiella pneumoniae isolates were resistant to antibiotics with high proportion. All 43 isolates of Klebssiella pneumoniae with ESBL (+) had higher proportion of antibiotic resistance than ESBL (-) isolates. Klebssiella pneumoniae carried antibiotic resistance genes blaNDM-1, blaKPC, blaOXA-48 were 11%, 2%, 2%. There were 24% isolates of Klebssiella pneumoniae carring virulence genes rmpA, 9% of them carring magA gene. Conclusions: Klebssiella pneumoniae is highly resistant to many antibiotics. Especially Klebssiella pneumoniae isolates ESBL (+). The proportion of Klebssiella pneumoniae carrying the antibiotic resistance blaNDM-1, blaKPC, blaOXA-48 genes were 11%, 2%, 2%. The proportion of carrying the virulence magA, rmpA genes is 24% and 9%. Key words: Klebsiella pneumonia, antibiotic resistant, PCR