Nalidixic Acid Research Articles

Study on Isolation of Organism and Antibiotic Sensitivity Pattern in Blood Culture of Enteric Fever Patients in a Tertiary Care Hospital in Bangladesh

A cross-sectional, observational study was conducted in the Department of Medicine, Mugda Medical College Hospital, Dhaka, Bangladesh, between March 2022 and September 2023, to observe the changing pattern of antibiotic sensitivity pattern among enteric pathogens causing enteric fever. A total of 50 blood culture and sensitivity reports were analyzed. Blood samples were derived from 50 patients included in this study, who were admitted into the medicine inpatient department of Mugda Medical College Hospital suffering from fever for at least 2 weeks and were confirmed having enteric fever. The predominant growth of two bacteria was observed in all (100%) samples. The most common organisms isolated were Salmonella typhi as typhoid fever pathogens and Salmonella paratyphi A as paratyphoid fever pathogens; these represented 88% and 12% of isolates respectively. Salmonella typhi organisms were found 100% sensitive to amoxycillin, trimethoprim-sulfamethoxazole, chloramphenicol, gentamicin, meropenem, cefepime, followed by imipenem (85%), ampicillin (81%), ceftriaxone (78%), levofloxacin (77%) and cefuroxime (77%). However, amoxicillin, trimethoprimsulfamethoxazole, ceftazidime, cefotaxime, ceftriaxone and chloramphenicol were found 100% sensitive to paratyphoid pathogens. Very high rate of resistance was seen against nalidixic acid (88%), piperacillin-tazobactam (50%), azithromycin (47%), co-amoxiclav (40%) and doxycycline (40%) in salmonella typhi infections, while nalidixic acid and azithromycin were found 100% resistant to Salmonella paratyphi A infection. Mugda Med Coll J. 2024; 7(2): 108-113

Prevalence and characteristics of ST131-O16 and ST131-O25b clones among extended-spectrum β-lactamase-producing Escherichia coli isolates causing bloodstream infection in Iran.

The multidrug-resistant clone identified as Escherichia coli sequence type 131 (E. coli ST131) has spread worldwide. The current study is one of the first comprehensive investigations to ascertain the prevalence of ST131 and molecularly characterize the ST131-O25b and ST131-O16 subgroups causing bloodstream infections in Iran. To this end, 119 consecutive, non-repetitive E. coli clinical strains were isolated from blood samples of patients with septicemia in different hospital wards for one year in Tehran. The isolates were provided by the laboratories of tertiary hospitals affiliated with Tehran University of Medical Sciences. The disk diffusion method was used to investigate the sensitivity of bacteria to antibiotics. All phylogroup B2 isolates were screened for E. coli ST131 status using a triplex PCR assay that combines the identification of ST131-O25b and -O16 clades. The seven putative virulence factor genes (kpmstII, fimH, afa A, iroN, Sat, ibeA, and ompT) and resistance genes (blaCTX-M-15, blaOXA-48, and blaCMY) were detected by PCR in E. coli ST131 isolates. The highest incidence of antibiotic resistance among 74/119 (62.18%) extended-spectrum β-lactamases-producing E. coli isolates was observed, respectively, against Nalidixic acid (82%), and Aztreonam (75%), followed by Ciprofloxacin (70%). Twenty out of 74 ESBL-producing E. coli isolates were found to be ST131 (27%), with 13 (65%) ST131-O25b and 7 (35%) ST131-O16 clades, respectively. The ST131-O16 isolates had a higher prevalence of resistance to Ceftriaxone, Amikacin, Aztreonam, and Cefepime than the -O25b ones. Concerning virulence capacity, our findings demonstrated that kpmstII, fimH, and ompT genes were found in 85%, 65%, and 30% of ST131 isolates, respectively. Our results reinforce the surveillance of E. coli ST131 clone dissemination as a major drug-resistant pathogen and an important new public health threat in Iran. Accumulation of multiple virulence factors, ESBL carriage, and identified antimicrobial resistance patterns of ST131-O25b and ST131-O16 clones indicate a necessity to develop strategies to control the spread of these isolates in both community and hospital settings.

Prevalence and Multidrug Resistance in Non-Typhoidal Salmonella in India: A 20-Year Outlook

Non-typhoidal Salmonella (NTS) infection poses a significant public health challenge globally, particularly in developing countries like India. NTS, predominantly represented by S. enterica serovars, is a major cause of intestinal and extra-intestinal infections. This review provides a comprehensive overview of longitudinal analyses of the prevalence of NTS in different regions of India encountered in the last 20 years and their antimicrobial resistance patterns. We followed several research investigations published during 2000–2024 to examine the incidence and prevalence of different serovars of NTS in several parts of India and followed published articles on NTS showing resistance to different antibiotics. We pointed out NTS serovars, which are predominantly isolated in various human and non-human sources, as observed in several investigations conducted in different regions of India. Our analysis revealed that, among serovars detected from various sources, S. Typhimurium is the most predominant one occurring across both human and non-human sources, followed by S. Enteritidis and S. Weltevreden. The occurrence of similar serovars of Salmonella in both human and non-human sources may be due to zoonotic transmission between animals and humans. Extensive research conducted across many geographic locations reveals that NTS isolates exhibit resistance to several antibiotics, with multidrug-resistance (MDR) being more common. These MDR strains basically show resistance to three or more classes of antibiotics, including critically important antimicrobials such as nalidixic acid, ciprofloxacin, and third-generation cephalosporins. Temporal trends suggest an alarming increase in resistance to these antibiotics, particularly in serovars such as S. Typhimurium and S. Enteritidis. Overall, the current article sheds light on the urgent need for surveillance, judicious antibiotic use, and the development of alternative treatment strategies to combat the rising tide of antibiotic-resistant NTS strains.

Isolation and characterization of plant growth promoting actinobacteria, Amycolatopsis samaneae (AM75), from the rice rhizosphere in mirza area, Assam, India

This study aimed to isolate plant growth-promoting actinobacteria from the rhizosphere of rice. Rhizospheric soil samples were collected from the Aijung variety of rice in the Mirza area, Kamrup district, Assam, India. The isolate AM75 identified as Amycolatopsis samaneae, was characterized as gram-positive and non-motile. It exhibited varied colony characteristics on different selective media. The isolate produce several enzymes including urease, nitrate reductase, lipase, catalase, and amylase but did not demonstrate cellulase or gelatinase activity. Notably, isolate AM75 displayed various plant growth-promoting activities such as siderophore activity, hydrogen cyanide (HCN) production, indole-3-acetic acid (IAA) production, and zinc solubilization. However, it did not produce hydrogen sulfide (H2S) or solubilize phosphate. The optimal growth conditions for AM75 were pH 7.2, 30ºC temperature, and NaCl 2.5% concentration. Additionally, AM75 exhibited inhibitory activity against the plant pathogens Erwinia chrysanthemi ATCC11660, Aspergillus niger ATCC6275, and Fusarium oxysporum ATCC62506. The isolate was resistant to standard antibiotics, including rifampcin, streptomycin, ampicillin, and nalidixic acid.

Phenotypic and WGS-derived antibiotic resistance patterns of Salmonella Enteritidis isolates from retail meat and environment during 2014 to 2019 in China

The emergence of multidrug-resistant (MDR) Salmonella Enteritidis has highlighted the importance of regularly monitoring for the occurrence of antibiotic-resistant strains. The current study combined phenotyping analysis and whole-genome-sequencing (WGS) to investigate the associations between the antibiotic-resistant phenotypes (ARPs) and genetic characteristics determinants in 95 Salmonella Enteritidis isolates from retail meat and environmental samples in China (2014–2019). Phenotypic analyses revealed that 70 isolates (73.68%) were MDR with 12 distinct resistance patterns. Most MDR strains (81.43%) had NAL-AMP-FIS-STR ± TET profiles, showing a fluctuating trend from 2015 to 2019, likely influenced by tetracycline withdrawal management. WGS identified four types of mutations in the gyrA gene were associated with nalidixic acid resistance. The co-carrying of blaTEM, sul2 and aph(6)-Id/aph(3″)-Ib was likely mediated by an X1-type plasmid, corresponding to resistance against ampicillin, sulfisoxazole, and streptomycin. Combining phenotypic analyses and WGS data, the 31 sequenced strains were primarily divided into two clusters, with most epidemic resistant strains in the largest cluster A. Identical ARP patterns observed across different sample types, regions, and isolation years but clustering together in cluster A suggested potential cross-contamination within the retail chain. Cluster B exhibited more diverse resistance patterns and genetic characteristics. Notably, three isolates in cluster B require special mention: a monophasic strain resistant to eight antibiotics, a strain exhibiting highly heteroresistance, and a strain with additional exotoxin genes. These results highlight the importance of ongoing surveillance and the utility of WGS to track and understand antibiotic resistance in Salmonella Enteritidis.

Comparison of pathogenicity factors of avian pathogenic and extraintestinal pathogenic Escherichia coli isolates originating from broiler chickens

ABSTRACT 1. E. coli is an opportunist pathogen of animals, including food-producing ones and humans. Chickens may be a notable source of pathogenic and antimicrobial resistant E. coli for transmission to humans. 2. This study compared virulence-associated genes (VGs) and antimicrobial resistance (AMR) in avian pathogenic E. coli (APEC) and extraintestinal pathogenic E. coli (ExPEC) isolates from broiler chickens, specifically APEC isolates in liver samples (n = 78) and ExPEC or non-ExPEC isolates in litter samples (n = 34). Virulence was evaluated by PCR for feoB, hlyF, iroN, iss, iutA and ompT genes, while AMR was evaluated by using antimicrobials from seven classes and detecting blaSHV, blaTEM, blaOXA, qnrB, stcM, mrc1, mrc2, sul1 and tetA genes. 3. The APEC isolates were found in 100% of livers, while ExPEC and non-ExPEC isolates were found in 44% and 56% of the litter samples. The predominant VG was feoB (100%), followed by ompT (63%), iutA (60%), iss (58%) and hlyF (43%). Surprisingly, iroN, omp T and iutA had higher prevalences in APEC isolates (85%, 96% and 96%, respectively) than in ExPEC isolates (73%, 87% and 73%, respectively) and non-ExPEC isolates (0% for all). The presence of all VG in 33% of isolates indicated high pathogenicity. 4. The isolates were phenotypically resistant to ampicillin (93%), ceftazidime (72%) and nalidixic acid (82%). All APEC and ExPEC isolates (100%) were multidrug resistant (MDR), while 63% of non-ExPEC isolates were MDR. Genotypic AMR testing revealed that 53% and 52% of all isolates had stcM and tetA, respectively. No isolate was positive for blaSHV, blaOXA, mrc1 or mrc2, which suggested the benefits of colistin for treating carbapenem-resistant enteric pathogens, due to the high resistance detected to meropenem (47%). 5. Given the potential pathogenicity of E. coli isolates, improving biosecurity practices in chicken flocks should be prioritised to eliminate transmission to humans through the food chain.

Antibiotic Use and Resistance Patterns in Escherichia coli Isolates from Rabbit Farms in Korhogo, Côte d'Ivoire

Backround: The use of antimicrobials in rabbit farming is essential for treating sick animals, controlling disease outbreaks, preventing illness, and promoting growth. However, their overuse and improper application contribute to the development and spread of resistant bacteria, posing a significant public health threat. This study aimed to assess antibiotic use and resistance patterns in Escherichia coli isolates from rabbit farms in Korhogo, Côte d'Ivoire. Methodology: Questionnaire was sent to 48 farmers, followed by the collection of fresh rabbit droppings from 25 farms. Escherichia coli was detected by inoculating droppings on chromogenic medium, followed by identification on the basis of biochemical characteristics. Resistance was studied using the Müeller-Hinton agar disc-diffusion method using 12 antibiotics. Results: Less than one-third of farmers (29.2%) used antibiotics, with oxytetracycline being the most commonly used. Antibiotics were primarily administered for digestive, skin, and respiratory diseases. The 56 E. coli isolates were highly resistant to colistin (82.1%), tetracycline (53.6%), amikacin (37.5%) and trimethoprim-sulfamethoxazole (32.1%). Resistance rate to cefotaxime, ceftriaxone, aztreonam, nalidixic acid and ciprofloxacin were very low (< 4%). However, all isolates were sensitive to amoxicillin + clavulanic acid and imipenem. The prevalence of ESBL E. coli was 3.6%. A significant number of E. coli isolate had a MAR index > 0.2. Conclusion: This study highlights the poor use of antibiotics on rabbit farms in Korhogo, with high levels of resistance to certain antibiotics of critical importance in human medicine. Hence the need to intensify awareness-raising and training of farmers in the rational use of antibiotics, in order to reduce the risk of dissemination of resistant bacteria within the population.

Antimicrobial Resistance Profiles of Escherichia coli Isolated from Food Animal Carcasses During 2010-2023 in South Korea.

Antimicrobial-resistant bacterial contamination of meat poses a significant global public health risk. We aimed to determine antimicrobial resistance profiles and trends of Escherichia coli recovered from carcasses of healthy food-producing animals in South Korea during 2010-2023. In total, 4748 E. coli isolates obtained from cattle (n = 1582), pigs (n = 1572), and chickens (n = 1594) were assessed for susceptibility to 12 antimicrobials. Antimicrobial resistance was different among samples. Overall, antimicrobial resistance was high in pigs and chicken carcasses. More than about 80% of isolates from pigs and chickens exhibited resistance to one or more antimicrobials. Among the tested antimicrobials, resistance to ampicillin, chloramphenicol, streptomycin, and tetracycline was significantly higher in pigs and chickens compared with cattle (p < 0.05). Moreover, chicken isolates showed much higher resistance to nalidixic acid and ciprofloxacin than other samples. Resistance to critically important antimicrobials, colistin, remained less than about 1%, while resistance to ceftiofur showed increased trends in pig and chicken samples. Higher multidrug-resistant (MDR) isolates were identified in chickens and pigs compared with cattle (p < 0.05). Furthermore, most MDR patterns include streptomycin and tetracycline resistance. MDR E. coli contaminating meat during slaughter can be transmitted to humans via the food chain. Thus, prudent use of antimicrobials and proper hygienic practices are urgently needed to reduce the risk of transmission.

Occurrence and cross contamination of Escherichia albertii in retail chicken outlets in Bangladesh.

Escherichia albertii is an emerging zoonotic pathogen linked to human gastrointestinal illnesses, with poultry meats being considered as a key source of human infections. However, there is little information regarding the distribution and characteristics of this bacterium in Bangladesh. This study investigated the occurrence, antimicrobial resistance, and virulence of E. albertii in chicken meats from retail outlets in Bangladesh. We collected samples from 61 dressed chickens across 17 retail shops from 4 upazilas, along with swabs from cloaca, processing utensils, and worker hands. Detection of E. albertii by species-specific PCR revealed substantial occurrence of E. albertii in retail chicken meat (63.9%), cloaca (71.4%), human hand (45.5%), bleeding cone (13.3%) and blade (10%). Almost all the E. albertii isolates (94.4%) exhibited resistance to at least one of the tested antimicrobials, among which 50% were multidrug resistant, including resistance to clinically relevant antimicrobials such as tetracycline, ampicillin, gentamicin, kanamycin, nalidixic acid and ciprofloxacin. Whole genome sequencing analysis identified the presence of corresponding antimicrobial resistance genes and critical virulence genes (eae, Eacdt). Notably, although wgSNP-based phylogenetic analysis showed the genomic diversity of the isolates, some of the isolates from the same shop displayed clonal relationships among meats, cloacal swabs, and human hand swabs, indicating contamination during processing. These findings highlight the public health risk posed by E. albertii in retail poultry, underlining the poultry's role as a potential vector for zoonotic transmission and the need for improved biosecurity and antimicrobial management practices in poultry production.

Antimicrobial resistance of Vibrio parahaemolyticus isolates from oyster sold in Thu Duc city, Ho Chi Minh City

This study was conducted to determine the rate of antibiotic resis tance in 75 Vibrio parahaemolyticus strains isolated from oysters sold in Thu Duc city, Ho Chi Minh City. The results of the anti biotic susceptibility test showed that all strains were sensitive to chloramphenicol and florfenicol, but resistant to ampicillin. The percentages of isolates resistance to streptomycin, tetracycline, trimethoprim/sulfamethoxazol, nalidixic acid, ciprofloxacin, enrofloxacin, nitrofurantoin were 56%; 4%; 4%; 4%; 22,7%; 38,7%, respectively. The percentage of multiple resistant isolates from two to six tested antibiotics was 96% and the multiple antibiotic resis tance (MAR) index ranged from 0.2 to 0.42.

An MDR Salmonella Enteritidis sublineage associated with gastroenteritis outbreaks and invasive disease in China.

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a commonly reported pathogen which adapts to multiple hosts and causes critical disease burden at a global level. Here, we investigated a recently derived epidemic sublineage with multidrug resistance (MDR), which have caused extended time-period and cross-regional gastroenteritis outbreaks and even invasive nontyphoidal Salmonella disease (iNTS) in China. Whole-genome sequencing and antimicrobial resistance (AMR) testing were applied to 729 Chinese S. Enteritidis isolates in relation to gastroenteritis outbreaks, gastrointestinal-sporadic and iNTS infections, spanning 28 years (1994-2021) in China. Phylogenomic analysis was performed to explore the population structure and evolutionary history of the Chinese isolates within a global context. Molecular investigations of AMR genes, virulence factors, mobile genetic elements and pan-genomes were also performed. The Chinese S. Enteritidis collections exhibited a high level of multidrug resistance (MDR), including high resistance to nalidixic acid (97.67%). Notably, the multidrug resistance rate of iNTS strains has significantly increased over the past decade. Phylogenomic analysis showed that the majority of the Chinese isolates (98.63%) were distributed in the global pandemic lineage L1, while the other lineages were highly continent-specific. Particularly, the Chinese isolates were predominantly distributed in sublineages L1.2 (37.45%) and L1.3 (59.26%), forming two main Chinese clades (MCC1&2). The most recent common ancestor of MCC1&2 dated back to 1944 and 2004, respectively. The lineage L1, especially MCC1&2, harbored the most amount of AMR determinants and virulence genes, which was mainly due to the presence of a hybrid virulence-resistance plasmid and coexistence of different types of AMR plasmids in S. Enteritidis. S. Enteritidis has evolved unique clonal clusters, MCC1&2, with critical MDR in China, which phylogenetically constitute an extension of the globally epidemic lineage and were characterized by distinct genetic traits. These clades have induced extensive outbreaks of gastroenteritis and serious cases of iNTS in China, underscoring the pressing nature and severity of this public health crisis. Implementing the One-Health strategy, longstanding routine surveillance and further genomic epidemiological studies are urgently required to capture epidemics, monitor changes in bacterial populations and determine the consequent risk to global public health.

Phenotypic Diversity and Antibiotic Resistance Pattern of Extended-Spectrum Beta-Lactamase (ESBLS) Producing Klebsiella pneumonia Isolated From Patients in Three Selected Centers in Isfahan, Iran

Background: Klebsiella pneumoniae is a significant pathogen responsible for a wide range of infections, particularly urinary tract infections (UTIs). We aimed to determine the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella strains and analyze their antibiotic resistance patterns in isolates collected from patients in three hospitals in Isfahan, Iran. Methods: This study was conducted over a 13-month period (2022–2023) in three educational hospitals in Isfahan, Iran. Out of 350 clinical specimens obtained from patients with UTIs, wounds, blood, and sputum, 142 Klebsiella isolates (40.5%) were identified and isolated according to standard methods. Antibiotic susceptibility was tested using the disk diffusion method according to CLSI standards, and ESBL production was confirmed using the combined disk method. Results: Among the 142 isolates, 113 (31%) were derived from urine, while 29 (8.2%) were from wounds, sputum, and blood samples. Antibiotic resistance was highest against nitrofurantoin (45.5%), sulfamethoxazole (44.8%), and nalidixic acid (41.3%). In contrast, the most effective antibiotic was amikacin, with an 85.7% susceptibility rate. Additionally, 125 isolates (88%) of were identified as ESBL positive showed resistant to at least 6 antibiotics used in this study. Conclusion: Amikacin remains the most effective antibiotic against Klebsiella species. However, the increasing prevalence of ESBL-producing strains poses a critical challenge for treating hospital-acquired infections. These findings highlight the need for rigorous antibiotic stewardship and infection control measures to mitigate the spread of resistant Klebsiella strains.

The fluoroquinolone compounds potentiate the antifungal activity of the echinocandins against Aspergillus fumigatus.

The antifungal drugs of the echinocandin family show high efficacy against Aspergillus fumigatus. However, their paradoxical effect, which restores fungal growth at high drug concentrations, and the emergence of resistant strains necessitate improvements. We identified 13 fluoroquinolone compounds from a chemical library containing 10,000 compounds that potentiate the antifungal activity of caspofungin. Among them, NE-E07 significantly enhanced the efficacy of echinocandins against A. fumigatus, including resistant strains, without potentiating other antifungal families like voriconazole or amphotericin B. Specifically, NE-E07 demonstrated a unique ability to potentiate caspofungin's activity against the echinocandin-resistant strain USHM-M0051 isolated from patients. Our experiments revealed that NE-E07, in combination with caspofungin, affected ergosterol biosynthesis in a manner consistent with azole drugs. Docking tests suggest NE-E07 has a high binding affinity with CYP51, which affects ergosterol biosynthesis similarly to azole drugs. Interestingly, known fluoroquinolones like ciprofloxacin, nalidixic acid, and norfloxacin did not show this potentiating effect, suggesting that NE-E07's unique structure is critical for its activity. Moreover, NE-E07 did not enhance echinocandin activity against Candida albicans or Cryptococcus neoformans, highlighting its specific action against A. fumigatus. In vivo studies demonstrated that co-treatment with NE-E07 and caspofungin increased the survival rate of mice infected with A. fumigatus. This significant improvement in survival underscores the potential clinical relevance of NE-E07 as a co-administered drug with echinocandins for treating fungal infections, particularly those resistant to echinocandins.

Anti-HIV-1 Effect of the Fluoroquinolone Enoxacin and Modulation of Pro-Viral hsa-miR-132 Processing in CEM-SS Cells.

Despite tremendous advances in antiretroviral therapy (ART) against HIV-1 infections, no cure or vaccination is available. Therefore, discovering novel therapeutic strategies remains an urgent need. In that sense, miRNAs and miRNA therapeutics have moved intensively into the focus of recent HIV-1-related investigations. A strong reciprocal interdependence has been demonstrated between HIV-1 infection and changes of the intrinsic cellular miRNA milieu. This interrelationship may direct potential alterations of the host cells' environment beneficial for the virus or its suppression of replication. Whether this tightly balanced and controlled battle can be exploited therapeutically remains to be further addressed. In this context, the fluoroquinolone antibiotic Enoxacin has been demonstrated as a potent modulator of miRNA processing. Here, we test the hypothesis that this applies also to selected HIV-1-related miRNAs. We studied the effect of Enoxacin on HIV-1 replication coupled with miRNA qRT-PCR analysis of HIV-1-related miRNAs in CEM-SS and MT-4 T-cells. The effects of miRNA mimic transfections combined with Enoxacin treatment on HIV-1 replication were assessed. Finally, we employed an in vitro DICER1 cleavage assay to study the effects of Enoxacin on a pro-HIV-1 miRNA hsa-miR-132 processing. We established that Enoxacin, but not the structurally similar compound nalidixic acid, exhibits strong anti-HIV-1 effects in the T-cell line CEM-SS, but not MT-4. We provide experimental data that this effect of Enoxacin is partly attributed to the specific downregulation of mature hsa-miR-132-3p, but not other tested pro- or anti-HIV-1 miRNAs, which is likely due to affecting DICER1 processing. Our findings show an anti-retroviral activity of Enoxacin at least in part by downregulation of hsa-miR-132-3p, which may be relevant for future antiviral therapeutic applications by modulation of the RNA interference pathway.

Prevalence and genomic insights of carbapenem resistant and ESBL producing Multidrug resistant Escherichia coli in urinary tract infections

Urinary tract infections are a common condition affecting people globally, with multidrug-resistant (MDR) Escherichia coli (E. coli) being a major causative agent. Antimicrobial susceptibility profiling was performed using the VITEK 2 automated system for 1254 E. coli isolates, revealing that 831(66.2%) isolates were determined as MDR E. coli. A significant resistance pattern was observed for nalidixic acid (86.04%), ampicillin (74.16%), ticarcillin (70.73%), cefalotin (65.23%), cefixime (62.68%), ciprofloxacin (55.18%), ceftriaxone (53.75%), amoxicillin-clavulanic acid (22.81%), ertapenem (7.18%), and fosfomycin (2.23%). Whole Genome Sequencing of Carbapenem-resistant E. coli (CREC)—CREC 3 (ST405), CREC 4 (ST448), and CREC 5 (ST167) was performed to determine genomic characteristics. CREC 3, CREC 4, and CREC 5 belong to the phylogroup D, B1, and A, respectively. The NDM-5 gene was common in all three isolates, with CTX-M-15 being present in CREC 3 and CREC 4. Virulence factors of CREC 3 (fliC, shuA), CREC 4 (spaS), CREC 5 (iucA, papH, papG, iucB, yigF), and plasmids (IncFIA, IncFIB) were identified to be significant. The use of pangenome analysis enhances our understanding of resistance traits of isolates ST167, ST405, and ST448, offering valuable insights into comparative genomics of uropathogenic MDR E. coli.

Houseflies (Musca domestica) as vectors of multidrug-resistant, ESBL-producing Escherichia coli in broiler poultry farms of North India: implications for antibiotic resistance transmission.

The transmission of antibiotic resistance (AR) from farm animals to healthy human communities, beyond the food chain, is often facilitated by biological vectors, notably houseflies (Musca domestica). This study aimed to evaluate the role of M. domestica collected from commercial broiler chicken farms as a carrier of multidrug-resistant (MDR), extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. E. coli were isolated separately from the housefly's external surface (ES) and internal homogenate (IH) to determine the primary AR transmission route within houseflies. Remarkably, 68.6% houseflies harboured E. coli. Isolated E. coli were evaluated for susceptibility to clinically relevant antibiotics and screened for the presence of 22 plasmid-borne AR genes (ARGs) using PCR. Results revealed significant resistance to key antibiotics, with > 70% of isolates resistant to ampicillin and > 50% resistant to tetracycline and nalidixic acid in both ES- and IH-derived E. coli. Notably, a significant prevalence of resistance was observed to third-generation cephalosporins. Additionally, > 80% of E. coli isolates were MDR. A statistically significant difference (unpaired t-test, p < 0.05) was observed in the presence of ESBL-producing E. coli between the houseflies' ES (28.14%) and IH (38.14%). ARGs such as, ampC, tetA, qnrS, strA, strB, and sul3 were frequently detected in both ES- and IH-derived E. coli isolates. Among the ESBL-producing genes, blaCTX-M was the most abundant. Pearson's correlation analysis predicted the ARGs responsible for phenotypic resistance to specific antibiotics. Farm-derived flies harboured a significantly higher number of MDR E. coli (unpaired t-test, p < 0.05) than the ones isolated from flies housing a distant non-farm environment. Conclusively, this study illustrates the role of houseflies as vectors for AR transmission from AR hotspots to human communities.

Phenotypic Antibiotic Resistance Patterns of Escherichia coli Isolates from Clinical UTI Samples and Municipal Wastewater in a Grenadian Community.

Antimicrobial resistance (AMR) is a growing global health threat. This study investigated antibiotic resistance in E. coli isolates from municipal wastewater (86 isolates) and clinical urinary tract infection (UTI) cases (34 isolates) in a Grenadian community, using data from January 2022 to October 2023. Antibiogram data, assessed per WHO guidelines for Critically Important antimicrobials (CIA), showed the highest resistance levels in both clinical and wastewater samples for ampicillin, followed by amoxicillin/clavulanic acid and nalidixic acid, all classified as Critically Important. Similar resistance was observed for sulfamethoxazole-trimethoprim (highly important) in both groups, with nitrofurantoin showing resistance in the important category. According to the WHO AWaRe classification, ampicillin (ACCESS group) had the highest resistance, while nitrofurantoin had the lowest across all samples. The WATCH group antibiotics, cefuroxime and cefoxitin, showed comparable resistance levels, whereas aztreonam from the RESERVE group (tested only in wastewater) was 100% sensitive. Multiple Antibiotic Resistance (MAR) index analysis revealed that 7% of wastewater and 38.2% of clinical samples had MAR values over 0.2, indicating prior antibiotic exposure in clinical isolates. These parallel patterns in wastewater and clinical samples highlight wastewater monitoring as a valuable tool for AMR surveillance, supporting antibiotic stewardship through ongoing environmental and clinical assessment.

Assessment of bacteriological and immunological markers in urinary tract infection and the effect of antibiotics on the isolated bacteria.

Urinary tract infections (UTIs) are recognized as the second most common medical condition, following respiratory infections. Despite the availability of numerous efficacious antibiotics for the management of UTIs, the rising incidence of bacterial resistance presents significant challenges in the treatment of these infections. Bacteria are endowed with the ability to reproduce and develop resistance mechanisms against antibiotics. The current investigation aimed to evaluate the susceptibility of bacterial isolates from urinary tract infections (UTIs) to a variety of antibiotics, including ciprofloxacin, trimethoprim, amikacin, gentamicin, tetracycline, chloramphenicol, nalidixic acid, nitrofurantoin, meropenem, and novobiocin. Additionally, the study sought to quantify the levels of the inflammatory immune marker interleukin-6 (IL-6) in UTI patients. It also explored the correlation between IL-6 levels in UTI patients and healthy controls, as well as the relationship between IL-6 levels and blood parameters in both infected and healthy individuals. The present study involved the collection of 155 samples from patients diagnosed with urinary tract infections of both genders and varying age groups, ranging from 15 to 75 years, at Salah al-Din General Hospital. The findings revealed that 102 urine samples tested positive for bacterial growth, resulting in a prevalence rate of 68%. In contrast, 53 urine samples were negative for bacterial growth, reflecting a prevalence rate of 32%. The diagnostic outcomes for all isolates, following the application of laboratory diagnostic methodologies, revealed a diverse array of bacterial species, including Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus saprophyticus, Staphylococcus aureus, and Staphylococcus epidermidis. The immunological analysis revealed a statistically significant increase (p < 0.05) in IL-6 concentrations in the positive control group compared to the levels observed in the infected cohort. Our study concluded that significant antibiotic resistance in UTI pathogens, emphasizing the need for tailored treatments.

Microbial Analysis of Vended Fruit Juices and Sauces Consumed in Restaurants in Narsingdi City, Bangladesh

Fresh fruit juices from cafes and restaurants are a popular beverage in Narsingdi city of Bangladesh during summer season. Food-borne outbreaks may arise from them since harmful germs from the unsanitary surroundings of the food preparation area easily infect them. The purpose of the current study was to identify the microbiological characteristics of various fruit juices and sauces consumed in different cafes and restaurants in Narsingdi City, Bangladesh. The detection of total viable bacterial load, total fungi count, coliforms, and some other pathogenic bacteria was checked in a total of thirty-nine juice and sauce samples, specifically of six categories of juices (orange, lemon, pineapple, sugarcane, papaya, and apple) and three categories of sauces (tomato sauce, mustard sauce, and tamarind sauce). Total viable bacteria in these samples ranged from 104 to 108 CFU/mL. Sixty percent of the samples had total coliforms (including Escherichia coli and Klebsiella spp.), all of which alarmingly exceeded the conventional bacteriological limits (1.0×104 CFU/mL) advised for fruit juices. Vibrio spp., Salmonella spp., and Staphylococcus spp. were identified as harmful microorganisms. Standard biochemical, microscopic, and cultural assays were used to identify each of these bacterial isolates. Sulfomethoxazole-trimethoprim, Ciprofloxacin, Tetracycline, Nalidixic Acid, Gentamicin, Ceftriazone, Ampicillin, and Netilmicin were among the drugs against which the isolates showed variable levels of drug resistance. The microbiological evaluation of these well-known ready-to-drink goods is therefore constantly required; otherwise, they could pose health risks.

Prevalence and antimicrobial resistant Campylobacter spp. in broiler chicken carcasses and hygiene practises in informal urban markets in a low-income setting.

Campylobacteriosis is one of the most commonly reported foodborne diseases and is of particular importance in low-income countries. More data is needed to better understand the epidemiology of Campylobacter spp. in food sold at informal markets, where most people in low-income countries buy their food. This study aimed to determine the prevalence and antimicrobial resistance (AMR) of Campylobacter spp. among broiler chicken carcasses sold at informal urban markets in Uganda and to gain more knowledge about hygienic handling practices and awareness of foodborne bacterial diseases among the market vendors. In total, 120 broiler chicken carcasses from 30 different markets were analysed using ISO 10272 and confirmed by PCR. AMR analyses were performed using the disc diffusion test. Epidemiological data on food safety practices and awareness was collected from the vendors using a questionnaire. Campylobacter spp. was isolated from 66% (79/120) of the carcasses; 32% were C. jejuni, 14% were C. coli and 54% comprised of a mixture of both species. All C. jejuni isolates showed resistance to tetracycline, 88% to ciprofloxacin and 28% to erythromycin. Of the C. coli isolates, 82% showed resistance to tetracycline, 73% to erythromycin and the quinolones ciprofloxacin and nalidixic acid. More than half of the vendors had heard about food-borne illnesses, but none knew about Campylobacter spp., and the knowledge regarding hygienic practices was low. These data calls for urgent interventions to improve food safety, protect the public from foodborne illness, and prevent the spreading of AMR.