Kirby-Bauer Disc Diffusion Method Research Articles

Prevalence and antibiotic susceptibility patterns of Escherichia coli and Staphylococcus aureus isolated from bioaerosols of local markets located in Agulu, Anambara State

There is a need for improved understanding of aerosol-acquired disease due to the increasing environmental load of antibiotic resistant bacteria. Multidrug-resistant Escherichia coli and Staphylococcus aureus are examples of bacteria for which the role of exposure to aerosolized organisms in disease transmission should be more closely evaluated globally. This study is aimed at evaluating the prevalence and antibiogram of S. aureus and E. coli present in market bioaerosols, located in Nwagu-Agulu, Anambra Nigeria. Impaction sample collection method was used to collect bioaerosol samples within the market using nutrient agar as the collection media, A combination of the cultural and microscopic features as well as selected biochemical tests were employed to identify the isolates. The Kirby-Bauer disk diffusion method was used to determine antibiotic resistance to selected commonly used antibiotics. A total of 76 S. aureus and 24 E. coli were isolated. Both organisms have been implicated in community-acquired infections. The most common bacteria isolated were Staphylococcus aureus. Varying levels of resistance were observed by these isolates to selected commonly use antibiotics. There is high prevalence of S. aureus and E. coli within Nwagu market Agulu, Anambra State, Eastern region of Nigeria. The organisms have very high rates of resistance to antibiotics (MDR) as reported by other workers. The government as well as Health professionals must play an important role in the prevention of community acquired infections via regular environmental monitoring of open markets bioaerosol and establishing a common permissible limits or concentration for bioaerosols within the markets.

Nasal carriage rate, associated factors, and antimicrobial susceptibility patterns of methicillin resistance Staphylococcus aureus among pre-clinical undergraduate students at the College of Health and Medical Sciences, Haramaya University, Ethiopia

BackgroundStaphylococcus aureus nasal carriage has been linked to higher rates of infection and morbidity. People with Methicillin-resistant Staphylococcus aureus can be a potential source of infection for others. University students living together in crowded conditions increase their risk of acquiring infections. The prevalence of S. aureus, particularly Methicillin-resistant Staphylococcus aureus nasal carriage, in Ethiopian university students is sparse.ObjectiveThis study aimed to determine the nasal carriage rate, associated factors, and antimicrobial susceptibility patterns of methicillin-resistant Staphylococcus aureus among pre-clinical students at the College of Health and Medical Sciences, Haramaya University, Ethiopia, from 1 July to 30 August 2022.MethodsAn institutional-based cross-sectional study was conducted among 270 randomly selected pre-clinical Health and Medical Sciences students. Data on associated factors were collected using pre-tested, structured questionnaires. A nasal swab was taken from each participant and sent to the microbiology laboratory via Amies transport media in a cold chain. There, it was cultivated using conventional techniques. The isolated colonies were found to be S. aureus, and its antimicrobial susceptibility was performed using the Kirby–Bauer disk diffusion method on Muller–Hinton agar. Methicillin-resistant Staphylococcus aureus expressing using cefoxitin based on CLSI breakpoint. Data were entered into Epi-Data version 4.4.2.1 and exported to the Statistical Package for Social Sciences (SPSS) software version 25 for analysis. Pearson’s chi-square test was performed to predict the associations between variables. A p-value less than 0.05 was regarded as statistically significant.ResultMethicillin-resistant Staphylococcus aureus nasal carriage was 5.9% (95% CI: 3.09–8.7) of cases of S. aureus nasal colonization, which was found to be 12.96% (95% CI: 8.85–16.96). Methicillin-resistant Staphylococcus aureus nasal colonization was significantly associated with the history of cigarette smoking (p = 0.000), intake of khat (p = 0.042), nose-picking habit (p = 0.003), history of sharing personal goods (p = 0.021), and history of hospitalizations (p = 0.00). All of the Methicillin-resistant Staphylococcus aureus isolates were resistant to ampicillin and cefoxitin.ConclusionBased on the findings, a considerable proportion of healthy students harbored Methicillin-resistant Staphylococcus aureus strains associated with behavioral factors. Furthermore, these isolates showed high resistance to cefoxitin and ampicillin. Hence, it is crucial to regularly test pre-clinical students to prevent endogenous infections and the spread of Methicillin-resistant Staphylococcus aureus.

Detection and evaluation of susceptibility to antibiotics in non-hydrogen sulfide-producing antibiotic-resistant soil microbe: Pseudomonas guariconensis.

Antimicrobial resistance in bacteria is a global threat that can make antibacterial treatments ineffective. One well-known method of antibiotic resistance and a common defensive mechanism in many harmful bacteria is the synthesis of endogenous hydrogen sulfide (H2S) in bacteria. In this study, soil bacteria were screened using the lead acetate agar test and the triple sugar iron test to determine that they were non-endogenous H2S producers. This was further validated by full genome analysis of the identified organism against the gene sequences of H2S-producing genes. Antibacterial resistance of the bacteria was phenotypically analyzed using the Kirby-Bauer disk diffusion method. Then, the effect of exogenous H2S on the antibiotic-resistant bacteria was checked in sodium sulfide, leading to antibiotic re-sensitization.

Antibiotic Resistance Profile of Staphylococcus aureus in Cancer Patients at Laquintinie Hospital in Douala, Littoral Region, Cameroon.

Cancer and chemotherapy predispose the patients to various bacterial infections. This study is aimed at isolating and establishing the distribution of antibiotic-resistant Staphylococcus aureus from fecal samples in subjects with cancer admitted to the Oncology Department at Laquintinie Hospital in Douala, in the Littoral Region of Cameroon. A cross-sectional study was conducted from October 2021 to March 2023. Cancer and noncancer patients were suffering from Staphylococcus aureus infection. The isolation of Staphylococcus aureus was based on culture on the specific medium. The Kirby-Bauer disk diffusion method was used for drug susceptibility testing. Of the 507 patients studied, 307 (60.55%) were cancer patients, compared to 200 (39.45%) noncancer patients. S. aureus was isolated in 81 (15.97%) participants, among which 62 (76.55%) were cancer patients and 19 (23.45%) were noncancer patients. In the study population, 31.92% of participants had breast cancer, followed by cervical cancer (13.68%) and leukemia (7.17%). Staphylococcus aureus isolates showed high resistance rates in cancer patients compared to noncancer patients to amoxicillin-clavulanic acid (AMC, 77.42% versus 31.58%), cefoxitin (FOX, 80.65% versus 63.16%), ciprofloxacin (CIP, 75.81% versus 26.32%), ofloxacin (OFX, 69.35% versus 31.58%), fusidic acid (FUS, 70.97% versus 53.63%), and tetracycline (TET, 85.48% versus 78.95%). Staphylococcus aureus showed a significant increase in multidrug-resistant (MDR) and methicillin-resistant (MRSA) phenotypes in cancer patients compared to noncancer patients (p < 0.05). The prevalence of MRSA was 76.54%, higher than that of methicillin-sensitive Staphylococcus aureus (MSSA) (23.46%). The frequency of MRSA was significantly higher (p < 0.001) in cancer patients (80.65%) than in noncancer patients (19.35%). This study showed that there is an association between antibiotic resistance and cancer status. Research and interventions must be focused on the cancer population to combat the appearance of MDR bacteria due to the loss of effectiveness of antibiotics.

Molecular Characterization and Antimicrobial Susceptibility Pattern of Microorganisms from Port Harcourt Correctional Center, Rivers State Nigeria

Correctional centers have been reported to be associated with several conditions predisposing inmates to health challenges as a result of exposure to disease causing microbial population. This study therefore targeted the Molecular Characterization and Antimicrobial susceptibility pattern of Microorganisms from Port Harcourt Correctional Center, Rivers State Nigeria. A total of 150 samples (100 from skin (upper arm) and 50 from wall surfaces) were collected using sterile swab sticks and immediately transported to Department of Microbiology Laboratory, Rivers State University for analyses, using standard microbiological techniques. Molecular characterization was done using Polymerase Chain reaction (PCR) and subjected to gene sequencing. The Kirby-Bauer Disc Diffusion method was used for the antimicrobial susceptibility test. Well in agar method was used to assess the susceptibility of the isolates to honey and Aloe Vera extract. The study revealed that 100% of all the bacterial isolates were resistant to Meropenem, Vancomycin, cefuroxime, and Ceftazidine, while 90% of the bacterial isolates were susceptible to Gentamicin, Cepftriaxone, Erythromycin, and Ciproflozaxine. Data showed the MAR index ranged from 0.3 to 0.8. Statistical analysis revealed there were no significant differences in the mean values of data obtained from the animate and inanimate surfaces (p &gt; 0.05). Molecular identification confirmed the isolates to be Kocuria palustris, Serretia liquefaciens, Klebsiella pneumonia, Enterococcus feacalis, Bacillus flexus, and Aspergillus niger. The results revealed that honey was more effective (100%) than Aloe Vera extract which inhibited only one of the Escherichia coli isolates. The study displayed the antimicrobial effect of honey against both Gram positive and Gram negative bacterial isolates. While adequate personal hygiene, proper sanitation, and spaced room should be encouraged, honey can be used in correctional centers to control bacterial skin infections.

Molecular insights into expression and silencing of resistance determinants in Staphylococcus aureus.

This study aimed to investigate the status of antimicrobial-resistant strains of Staphylococcus aureus in Pakistan, their association in terms of co-occurrence with the biofilm-forming genes, resistance profiling and associated discrepancies in diagnostic methods. A total of 384 milk samples from bovine was collected by using convenient sampling technique and were initially screened for subclinical mastitis, further preceded by isolation and confirmation of S. aureus. The S. aureus isolates were subjected to evaluation of antimicrobial resistance by phenotypic identification using Kirby-Bauer disc diffusion method, while the genotypic estimation was done by polymerase chain reaction to declare isolates as methicillin, beta-lactam, vancomycin, tetracycline, and aminoglycoside resistant S. aureus (MRSA, BRSA, VRSA, TRSA, and ARSA), respectively. The current study revealed an overall prevalence of subclinical mastitis and S. aureus to be 59.11% and 46.69%, respectively. On a phenotypic basis, the prevalence of MRSA, BRSA, VRSA, TRSA, and ARSA was found to be 44.33%, 58.49%, 20.75%, 35.84%, and 30.18%, respectively. The results of PCR analysis showed that 46.80% of the tested isolates were declared as MRSA, 37.09% as BRSA, and 36.36% as VRSA, while the occurrence of TRSA and ARSA was observed in 26.31% and 18.75%, respectively. The current study also reported the existence of biofilm-producing genes (icaA and icaD) in 49.06% and 40.57% isolates, respectively. Lastly, this study also reported a high incidence of discrepancies for both genotypic and phenotypic identification methods of resistance evaluation, with the highest discrepancy ratio for the accA-aphD gene, followed by tetK, vanB, blaZ, and mecA genes. The study concluded that different antibiotic resistance strains of S. aureus are prevalent in study districts with high potential to transmit between human populations. The study also determined that there are multiple resistance determinants and mechanisms that are responsible for the silencing and expression of antibiotic resistance genes.

PHENOTYPIC DETECTION OF ESBL AND AMPC BETA LACTAMASES AMONG GRAM-NEGATIVE ISOLATES FROM CLINICAL SAMPLES IN A TERTIARY CARE HOSPITAL

Objectives: Drug-resistant Gram-negative bacilli expressing extended-spectrum beta-lactamases (ESBLs) and AmpC pose a serious therapeutic threat in nosocomial infections. Cost-effective screening methods are a boon to patients. This study aims to detect gram-negative bacilli and their antibiotic sensitivity patterns, as well as detect the ESBL and AmpC-producing isolates among Gram-negative bacilli. Methods: A prospective study was conducted with 150 samples. Gram-negative bacilli were isolated, and their antibiotic sensitivity tests were performed by the Kirby–Bauer disk diffusion method. Potential ESBL producers were screened using Ceftazidime disc, and AmpC producers were screened by Cefoxitin discs by the disc diffusion method. ESBL producers were confirmed by the combined disc diffusion assay method using ceftazidime and ceftazidime/Clavulanic acid disc. AmpC producers were confirmed by the Cefoxitin Cloxacillin Double Disc Synergy Test. Results: About 38% of 150 samples were gram-negative bacilli, of which 40.35% were Escherichia coli, followed by Pseudomonas aeruginosa (35.08%). Maximum sensitivity by E. coli was found toward imipenem, meropenem, and cotrimoxazole. P. aeruginosa showed maximum sensitivity toward piperacillin/tazobactam, imipenem, meropenem, and ceftazidime. 28.07% of Gram-negative isolates were ESBL producers, with E. coli (11 isolates) being the maximum, and 15.78% were AmpC producers, with E. coli (four isolates) being the maximum. Seven isolates were both ESBL and AmpC producers. Conclusion: Routine screening and timely reporting of ESBL and AmpC producers help in preventing the spread of multidrug-resistant strains. Antibiotic resistance surveillance helps in the implementation of strict infection control and prevention practices.

Detection of Biofilm Production and Antibiotic Susceptibility Pattern among Clinically Isolated Staphylococcus aureus.

The increasing antibiotic resistance and the ability to form biofilms in medical devices have become the leading cause of severe infections associated with Staphylococcus aureus (S. aureus). Since the bacteria living in biofilms can exhibit 10- to 1,000-fold increase in antibiotic resistance and implicate chronic infectious diseases, the detection of S. aureus ability to form biofilms is of great importance for managing, minimizing, and effectively treating infections caused by it. This study aimed to compare the tube and tissue culture methods to detect biofilm production and antibiotic susceptibility in MRSA and MSSA. The S. aureus isolates were identified by the examination of the colony morphology, Gram staining, and various biochemical tests. Antimicrobial susceptibility testing of all isolates was performed by the modified Kirby-Bauer disc diffusion method as recommended by CLSI guidelines. MRSA screening was performed phenotypically using a cefoxitin disc (30 µg). Isolates were tested for inducible resistance using the D-test, and two phenotypic methods detected biofilm formation. Among 982 nonrepeated clinical specimens, S. aureus was isolated from 103 (10.48%). Among 103 clinical isolates of S. aureus, 54 (52.42%) isolates were MRSA, and 49 (47.57%) were MSSA. Among 54 MRSA isolates, the inducible MLSB phenotype was observed in 23/54 (42.59%) with a positive D-test. By TCP method, 26 (48.1%) MRSA isolates were strong biofilm producers, whereas, among all MSSA isolates, only 6 (12.2%) were strong biofilm producers. MRSA showed strong biofilm production in comparison with MSSA. The TCP method is a recommended reliable method to detect the biofilm among S. aureus isolates, and the TM method could be useful for the screening of biofilm production in S. aureus in the routine clinical laboratory.

An In Vitro Study to Evaluate the Synergy of Baptisia tinctoria against Salmonella typhi

AbstractAs a consequence of gradual emergence of anti-microbial resistance, the anti-biogram profile of the microbe Salmonella typhi has undergone substantial changes. Patients frequently utilise homeopathy for the flu season and other serious illnesses. Although the use of Baptisia tinctoria (BT) is extensively described in homeopathic literature and in phytomedicine, scientific exploration has never been done. In this study, we have made an effort to understand the anti-typhoidal effect of BT at different concentrations. S. typhi (ATCC 6539) from a freshly prepared stock culture was used in this experiment. We also procured an international strain of Escherichia coli (ATCC 25922 strain) which was taken as control. The antibiotic susceptibility patterns of the isolates were determined by the Kirby-Bauer disc diffusion method according to the Clinical and Laboratory Standards Institute guidelines and interpretative criteria (National Committee for Clinical Laboratory Standards 2000) using antibiotic discs (Hi Media Laboratory. Pvt. Ltd., Mumbai, Maharashtra, India), namely cefotaxime (30 μg), ceftazidime (30 μg), ciprofloxacin (5 μg), tetracycline (30 μg), chloramphenicol (30 μg), streptomycin (10 μg), ampicillin (10 μg), gentamicin (10 μg), kanamycin (30 μg), nalidixic acid (30 μg) and trimethoprim (5 μg). BT in its 6CH potency showed the greatest growth inhibition zone, not just amidst the homeopathic potency gradient. It has shown the highest growth inhibition zone of 28mm, more than any conventional antibiotic. Ethanolic extract of BT can be considered to combat against array of infections caused by S. typhi species alongside that it can also be considered as adjuvant with conventional antibiotics for better result.

Current Trends of Resistance Among Gram Negative and Gram Positive Bacteria Isolated from Tertiary Care Hospital

Introduction: Nosocomial infections (NIs) following antimicrobial resistance becomes serious public health concern across the world. It affects the length of hospital stay and cost burden on the health care system. Rapid increase in resistance against commonly used antibiotics results in emergence of multi-drug resistant organisms. Material and Methods: This retrospective study was done at CMH Sialkot over the period of six months. All types of clinical samples were included and were processed according to standard microbiological procedures. Organisms were identified by using different biochemical tests. AST were performed by Kirby-Bauer disc diffusion method according to CLSI guidelines. Results: Total 402 organisms were isolated among which 57% were gram positive while 43% were Gram negative bacteria. MRSA (31%) was most prevalent in Gram positive bacteria while E.coli(50%) was found to be most common in Gram negative bacteria. Gram-positive bacteria showed maximum resistance against Fluoroquinolones, while Co-trimoxazole and Cephalosporins were least susceptible against Gram-negative bacteria. Conclusion: Nosocomial infections Because of their importance, antibiotic usage policies should be taken and implemented on a priority basis in the agenda of the infection control committees of hospitals.

Comprehensive Profiling of Klebsiella in Surface Waters from Northern Portugal: Understanding Patterns in Prevalence, Antibiotic Resistance, and Biofilm Formation

This study investigates the prevalence of resistance and virulence genes in Klebsiella isolates from surface waters in Northern Portugal, within the broader context of freshwater quality challenges in Southern Europe. The aim of this research is to explain how Klebsiella dynamics, antibiotic resistance, and biofilm formation interact in surface waters. Antimicrobial susceptibility was examined using the Kirby–Bauer disk diffusion method against 11 antibiotics and screening for Extended-Spectrum Beta-Lactamase (ESBL) production using the double-disk synergy. PCR was employed to detect resistance and virulence genes, while biofilm production was assessed using the microplate method. Out of 77 water isolates, 33 Klebsiella (14 Klebsiella spp. and 19 K. pneumoniae strains) were isolated. ESBL production was observed in 36.8% of K. pneumoniae and 28.6% of Klebsiella spp. High resistance rates to blaCTX-U were observed in both. The papC gene was prevalent, signifying potential environmental risks. Biofilm production averaged 81.3% for K. pneumoniae and 86.9% for Klebsiella spp. These findings underscore the intricate interplay between Klebsiella’s dynamics and freshwater quality, with ESBL’s prevalence raising concerns about waterborne dissemination and public health implications. This work supports the need for vigilance of Klebsiella in surface waters in Southern Europe.

Comparative Study of Biofilm and Non-Biofilm Producing Klebsiella pneumoniae with Special Reference to Metallo-Beta-Lactamase Production

Klebsiella pneumoniae is one of the most common bacteria among all biofilm-producing as well as the beta-lactamase producing strains, which is responsible for multi-drug resistance. For better therapeutic applications, it is important to detect the biofilm production by Klebsiella pneumoniae and their antibiogram along with the ability to produce ESBL, MBL, and AmpC β-lactamases. The aim of the study was to determine the prevalence of biofilm formation and ESBL, MBL, AmpC β-lactamase phenotypes in K. pneumoniae as well as the antibiogram of all (biofilm and MBL-producing and non-producing) isolates of K. pneumoniae. Isolates of K. pneumoniae were tested for biofilm formation by the Congo-red agar method. ESBL, MBL, and AmpC β-lactamase detection were done by both screening and confirmatory tests as per CLSI guidelines. The antibiogram was obtained by the Kirby-Bauer disc diffusion method. Among the total 100 isolates of K. pneumoniae, 40% were biofilm-producing. Most of them were from urine specimens. Out of biofilm-producing isolates, ESBL – 28%, MBL- 47% and AmpC β-lactamase- 25.8% producers were observed. K. pneumoniae isolates were seen to have maximum resistance to ceftazidime and maximum sensitivity to nitrofurantoin. Study findings suggest the importance of assessment of biofilm formation for better treatment. The scenario further worsens if such biofilm-producing isolates are also MBL-positive leading to limited therapeutic options.

Prevalence and Antibiotic Susceptibility Pattern of Pseudomonas Aeruginosa from the Foot Ulcer of Diabetic Patients in Hayatabad Medical Complex Peshawar, Pakistan

Background: Diabetic foot ulcers (DFUs) are a major complication of diabetes mellitus, affecting 15% of diabetic patients and often leading to severe outcomes like amputation. These ulcers frequently become infected with bacteria such as Pseudomonas aeruginosa, which is known for its robust antibiotic resistance. Objective: To investigate the prevalence and antibiotic susceptibility patterns of Pseudomonas aeruginosa isolated from the foot ulcers of diabetic patients in Hayatabad Medical Complex, Peshawar. Methods: A total of 103 clinical samples from diabetic foot ulcers were collected and analyzed for the presence of Pseudomonas aeruginosa using culture techniques and biochemical tests. The antibiotic susceptibility was assessed using the Kirby-Bauer disk diffusion method to identify effective treatments. Results: Pseudomonas aeruginosa was identified in 48 (46.60%) of the samples. High resistance was noted against amoxicillin-clavulanic acid (100%), and notable sensitivity was observed to gentamicin (79.16%) and cefoperazone-sulbactam (87.5%). The susceptibility to other tested antibiotics varied, with moderate resistance seen in agents like cefotaxime (25%) and trimethoprim-sulfamethoxazole (33.33%). Conclusion: The study highlights a significant presence of Pseudomonas aeruginosa in diabetic foot ulcers with substantial antibiotic resistance, emphasizing the need for precise susceptibility testing to guide effective treatment strategies.

Lipase and Protease Production Ability of Multi-drug Resistant Bacteria Worsens the Outcomes of Wound Infections

Background: Surgical site infections are one of the major clinical problems in surgical departments that cost hundreds of millions of dollars to healthcare systems around the world. Aim: The study aimed to address the pressing issue of surgical site infections, which pose significant clinical and financial burdens on healthcare systems globally. Recognizing the substantial costs incurred due to these infections, the research has focused on understanding the role of lipase and protease production by multi-drug resistant bacteria isolated from surgical wounds in the development of post-surgical wound infections. Methods: For these purposes, 153 pus specimens were collected from patients with severe post-surgical wound infections having prolonged hospital stays. The specimens were inoculated on appropriate culture media. Gram staining and biochemical tests were used for the identification of bacterial growth on suitable culture media after 24 hours of incubation. The isolated pathogens were then applied for lipase and protease, key enzymes that could contribute to wound development, on tributyrin and skimmed milk agar, respectively. Following the CSLI guidelines, the Kirby-Bauer disc diffusion method was used to assess antibiotic susceptibility patterns. The results revealed that a significant proportion of the samples (127 out of 153) showed bacterial growth of Gram-negative (n = 66) and Gram-positive (n = 61) bacteria. In total, isolated 37 subjects were declared MDR due to their resistance to three or more than three antimicrobial agents. The most prevalent bacteria were Staphylococcus aureus (29.13%), followed by S. epidermidis (18.89%), Klebsiella pneumoniae (18.89%), Escherichia coli (14.96%), Pseudomonas aeruginosa (10.23%), and Proteus mirabilis (7.87%). Moreover, a considerable number of these bacteria exhibited lipase and protease activity with 70 bacterial strains as lipase positive on tributyrin agar, whereas 74 bacteria showed protease activity on skimmed milk agar with P. aeruginosa as the highest lipase (69.23%) and protease (76.92%) producer, followed by S. aureus (lipase 62.16% and protease 70.27%). Results: The antimicrobial resistance was evaluated among enzyme producers and non-producers and it was found that the lipase and protease-producing bacteria revealed higher resistance to selected antibiotics than non-producers. Notably, fosfomycin and carbapenem were identified as effective antibiotics against the isolated bacterial strains. However, gram-positive bacteria displayed high resistance to lincomycin and clindamycin, while gram-negative bacteria were more resistant to cefuroxime and gentamicin. Conclusion: In conclusion, the findings suggest that lipases and proteases produced by bacteria could contribute to drug resistance and act as virulence factors in the development of surgical site infections. Understanding the role of these enzymes may inform strategies for preventing and managing post-surgical wound infections more effectively.

Antimicrobial susceptibility patterns of Listeria monocytogenes isolated from fresh produce in KwaZulu-Natal Province, South Africa

Fresh, ready-to-eat produce is frequently irrigated with untreated water, making it a leading cause of food-borne illness outbreaks worldwide. This study investigated the presence of Listeria monocytogenes in fresh produce that was grown using river water. Standard biochemical tests were used for the identification of L. monocytogenes isolated from river water used for irrigation, and from fresh produce including lettuce, spinach, and pumpkin. The inlA gene of L. monocytogenes was molecularly identified using PCR amplification. The susceptibility of L. monocytogenes isolates to antimicrobial agents was assessed using the Kirby-Bauer disc diffusion method. The presence of the amplified inlA gene (800 bp) indicated that all of the fresh produce and river water samples were contaminated with virulent L. monocytogenes. Lettuce and spinach exhibited higher quantities of L. monocytogenes, with lettuce recording 87 CFU/g and spinach recording 71 CFU/g. The L. monocytogenes isolates from spinach and lettuce sources showed significant resistance to colistin (56.2% and 53.3%, respectively) as well as ampicillin (68.8% and 53.3%, respectively). Moreover, lettuce (40%) and spinach (31%) exhibited a common resistance pattern of AMP-CHL-CT-KAN-PIP-ERY-TET, with a maximum MAR index value of 0.54. Our research demonstrates the transmission of multidrug-resistant L. monocytogenes from irrigation river water to fresh produce. Hence, the ingestion of ready-to-eat fresh produce carries the potential for human listeriosis, particularly among individuals with compromised immune systems.

Incidence of drug resistance bacterial isolates from different Pyoderma cases attending at tertiary care hospital of Central Nepal

Background &amp; Objectives: Pyoderma is defined as any purulent skin disease and represents infections in epidermis and dermis including hair follicles. Thus, this study was conducted to find out incidence and bacteriological profile of pyodermas as well as to determine their antibiotic susceptibility test of isolated bacteria. Materials and Methods: The samples were collected in dermatological OPD and sent the collected samples immediately to bacteriology laboratory for culture and sensitivity tests from December 2018 to May 2019 A.D. Antimicrobial susceptibility testing was done using Kirby–Bauer disc diffusion method and the results were interpreted according to the CLSI guidelines. Quality control of the test was done by standard ATCC strains of S.aureus (ATCC 25923), E.coli (ATCC 25922). Results: The incidence of pyoderma was 3.24%. Maximum cases were detected in the age group below 13 years of age. Primary pyoderma (61.8%) was more frequent when compared to secondary pyoderma (38.2%). The highest number of organism isolated was S. aureus (24.7%) from different cases of pyoderma followed by E. coli (8.2%), CONS (6.1%) and Klebsiella pneumoniae (5.1%) whereas other organisms were found in less number. Gram positive bacteria mainly S. aureus and other isolates for the cause of pyoderma were mostly resistant to penicillin (100%), ciprofloxacillin (75.0%) and clindamycin (79.2%). Gram negative E. coli (8.2%) was second most bacterial isolates and others GNB isolates were (14/63) where resistance pattern were seen more (75.0%) in each ceftrixone and imipenem. Conclusion: Incidence of pyoderma was low among the patients visiting to the Dermatology Department. Antibiotic resistance is increasing day by day; therefore, routine culture and sensitivity tests are essential to guide proper treatment procedure.

Whole-genome sequencing of clinical isolates of Citrobacter Europaeus in China carrying blaOXA−48 and blaNDM−1

ObjectiveTo analyze the clinical infection characteristics and genetic environments of resistance genes in carbapenem-resistant Citrobacter europaeus using whole-genome sequencing.MethodsThe susceptibility of two clinical isolates of C. europaeus (WF0003 and WF1643) to 24 antimicrobial agents was assessed using the BD Phoenix™ M50 System and Kirby-Bauer (K-B) disk-diffusion method. Whole-genome sequencing was performed on the Illumina and Nanopore platforms, and ABRicate software was used to predict resistance and virulence genes of carbapenem-resistant C. europaeus. The characteristics of plasmids carrying carbapenem-resistance genes and their genetic environments were analyzed. Single nucleotide polymorphisms were used to construct a phylogenetic tree to analyze the homology of these two C. europaeus strains with ten strains of C. europaeus in the NCBI database.ResultsThe two strains of carbapenem-resistant C. europaeus are resistant to various antimicrobial agents, particularly carbapenems and β-lactams. WF0003 carries blaNDM− 1, which is located on an IncX3 plasmid that has high homology to the pNDM-HN380 plasmid. blaNDM− 1 is located on a truncated Tn125. It differs from Tn125 by the insertion of IS5 in the upstream ISAba125 and the deletion of the downstream ISAba125, which is replaced by IS26. WF1643 carries blaOXA− 48 in a Tn1999 transposon on the IncL/M plasmid, carrying only that single drug resistance gene. Homology analysis of these two strains of C. europaeus with ten C. europaeus strains in the NCBI database revealed that the 12 strains can be classified into three clades, with both WF0003 and WF1643 in the B clade.ConclusionTo the best of our knowledge, this is the first study to report an IncX3 plasmid carrying blaNDM− 1 in C. europaeus in China. C. europaeus strains harboring carbapenem-resistance genes are concerning in relation to the spread of antimicrobial resistance, and the presence of carbapenem-resistance genes in C. europaeus should be continuously monitored.

PCR Detection of Extended Spectrum β-Lactamase from Some Gram Negative Bacteria of Clinical Source

Beta-lactamase-producing microorganisms present distinct challenges in health care systems around the world as a result of the extensive utilization of broad-spectrum antibiotics. The objective of this research endeavor was to ascertain the antibiotic resistance profile and presence of β-lactamase genes in Gram-negative bacteria that had been previously identified and collected from laboratory work benches at the Department of Microbiology and Parasitology, UCH, located in Ibadan, South-West Nigeria. The Kirby-Bauer disc diffusion method was used to assess antibiotic susceptibility on all the isolates, and the double disc synergy test was used to validate extended spectrum beta-lactamase (ESBL) production phenotypically. The PCR techniques were used to detect β-lactamase genes. The sample distribution of the forty clinical isolates were collected from the work benches and the distribution was: urine (17), blood (9), wound (6), sputum (4), amniotic fluid (3) and tracheal aspirate (1). Klebsiella pneumoniae was the most prevalent organism with 17 isolates ( 42.5% ). Out of the 40 isolates that were obtained, 21 were ESBL producers and the distribution was as follows: Klebsiella pneumoniae (9), Escherichia coli (6), Enterobacter cloacae (2), Enterobacter aerogenes (1), Pseudomonas aeruginosa (1), Acinetobacter baumannii (1) and Hafnia alvei (1). The majority of the clinical isolates showed considerable resistance to antibiotic classes that were tested, with amoxicillin-clavulanate showing the highest resistance rate at 65%. Out of all the ESBL producers, 35.3% had blaTEM, 29.4% had blaCTX-M, 23.5% had blaSHV, and 11.8% had blaCMY. AmpC β-lactamases, Antibiotic resistance, Disc diffusion, Gram-negative bacteria, Polymerase chain reaction.

Bacteriological evaluation, antibiogram, and phenotypic detection of MBL-producing gram-negative bacteria isolated from outdoor patients with otorrhea attending Ayub medical Complex

Otitis media is frequently prevalent in developing countries and is primarily caused by bacteria. The current study aimed to study the patients to assess the occurrence rate, susceptibility pattern, and prevalence rate of metallo beta-lactamase (MBL) producing gram-negative bacteria to prevent the prevalent strains and direct the physicians to appropriate antibiotic therapy. The research study was conducted over nine-months, from November 2020 to July 2021, in which a total of 110 samples were collected from the outdoor-patients’ ear, nose, and throat (ENT) wards using sterile swabs and inoculated immediately on suitable culture media. The isolates were identified via conventional biochemical tests, and the susceptibility pattern of each isolate was tested using the Kirby-Bauer disc diffusion method. Out of the 110 total samples, merely 88.18% (97/110) ear samples were detected positive for the various strains of bacteria both in male and female patients with a mean age of 18.21 ± 15.86, contributing 54.64% and 45.36%, respectively. The most prevalent bacterial strain was Staphylococcus aureus (49.48%), followed by Pseudomonas aeruginosa (16.50%), Proteus spp. (13.40%), S. epidermidis (7.22%), E. coli (6.19%), S. saprophyticus (4.12%), and Klebsiella spp. (3.09%). Of the gram-negative isolated strains, only 18.75% (3/16) of the P. aeruginosa strains exhibited MBL production. A high prevalence rate was observed in the age-group 0–4 years (19.58%), followed by the age-groups, 5–9 and 15–19 (16.49% each), and the age-group >39 (10.31%). Levofloxacin, ciprofloxacin, amikacin, and fusidic acid were highly effective against the gram-positive, whereas ciprofloxacin, amikacin, and levofloxacin were potent against the gram-negative (except P. aeruginosa), while carbenicillin, meropenem and imipenem against the P. aeruginosa. The MBL-producers were highly (100%) resistant to IMP and MEM while highly (100%) sensitive to CAZ. In conclusion, the current study showed a high prevalence of S. aureus, P. aeruginosa, and MBL-producing P. aeruginosa (18.75%). Nevertheless, a high degree of resistance to antibiotics was noted, which could not be ignored.

Prevalence of Urinary Tract Infections and Antibiogram of Bacteria Isolated From Children With Sickle Cell Disease in Tanzania.

Introduction Individuals with sickle cell disease (SCD) are particularly vulnerable to urinary tract infections (UTIs) due to immunological deficits and renal abnormalities associated with the disorder. These infections can exacerbate underlying health issues and lead to severe complications if not managed promptly and effectively. Due to the heightened risk and potential consequences of UTIs in this population, this study aimed to determine their prevalence and explore the resistance patterns of causative pathogens among children attending the SCD Clinic at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania. Focusing on this demographic group, we sought to provide targeted insights to inform better clinical protocols and intervention strategies in regions heavily affected by SCD. Materials and methods This prospective cross-sectional study was conducted at the MNH, Dar es Salaam, Tanzania, with an enrollment over two months from 19th March to 21st May 2015. We diagnosed UTIs in children with SCD using dipstick and culture methods. Antibiotic susceptibility was assessed using the Kirby-Bauer disc diffusion method, evaluating resistance patterns to antibiotics such as ampicillin, cloxacillin, erythromycin, chloramphenicol, ceftriaxone, and trimethoprim-sulfamethoxazole. The diagnostic accuracy of the dipstick and culture methods was validated to ensure reliability in detecting UTIs. Statistical analysis was conducted using Statistical Product and Service Solutions (SPSS) software (Released 2019; IBM Corp., Armonk, New York, United States). Results Among the 250 children, 56 (22.4%) were UTI-positive according to the culture method and 62 (24.8%) were UTI-positive according to the dipstick test. Girls were more likely to be UTI-positive than boys (29.1% and 13.6%, respectively; p-value = 0.011). Escherichia coli was the most common uropathogen, followed by Klebsiella, Staphylococcus, Proteus, and Pseudomonas (44.2%, 26.9%, 21.2%, 3.8%, and 1.9%, respectively). All isolates were resistant to ampiclox. Resistance rates to ampicillin, erythromycin, cotrimoxazole, chloramphenicol, and ceftriaxone were 94.2%, 76.9%, 59.6%, 46.2%, and 21.2%, respectively. Conclusion This study indicated that dipsticks diagnosed more UTIs. The prevalence was higher in girls than in boys. Escherichia coli was the most commonly isolated antibiotic-resistant organism. High resistance levels were observed against the combination of ampicillin and cloxacillin. However,the isolates were less resistant to ceftriaxone. These results call for increased surveillance of resistant uropathogens in the pediatric population with SCD.