Citrobacter Species Research Articles

69 Urinary tract infections in preterm infants: Review in two Canadian tertiary centers

Abstract Background Urinary tract infections (UTI) in premature infants are commonly seen in the neonatal intensive care unit (NICU). The reported prevalence of UTI in this population ranges from 1.9-12.2% due to the lack of standardized criteria for UTI among infants less than two months of age. Enterococcus and Enterobacteriaceae are well known to cause UTI and their resistance pattern has been reported to be rising in the neonatal nosocomial infections worldwide. Objectives To describe the epidemiology, microbiology, and antimicrobial treatment for UTI in premature infants based on different diagnostic criteria. Design/Methods This retrospective study (2019-2022) included infants born at <33 weeks of gestational age (GA) with positive urine cultures and ≥5 days of antimicrobials treatment. We collected data from two tertiary level NICUs in Canada, including demographics, microbial susceptibility patterns, urinalysis and imaging results, and antibiotic treatment. Results We identified 43 infants managed as UTI based on physicians’ discretions. The median GA at birth was 26-27 weeks, while the median onset of first UTI ranged 39-80 days, with male predominance [Table 2]. Mixed growth of organisms constituted 21-42% of cases of UTI [Table 1]. Among UTI cases with only single growth organism, we found 53.5% and 18.6% cases fulfilled UTI diagnostic criteria based on the concentration of colony forming units (CFU) of >104/mL or >107/L and >105/mL or >108/L, respectively [Table 1]. Of these cases, 67.4% of infants had urinalysis sent with the culture, and the higher the concentration of CFU, the more likely the samples showed positive nitrites on urinalysis, with 100% correlation among those with CFU >105/mL or >108/L. [Table 1] The most common pathogens were Enterococcus species, E.Coli, Klebsiella species, Citrobacter species and Enterobacter cloacae complex [Table 2]. Among gram negative bacilli (E. Coli and Klebsiella species), greater than 42-80% were resistant to 3rd generation cephalosporins (3GC). We did not identify any vancomycin-resistant Enterococcus strains. Median duration of antimicrobial treatment ranged from 8-13 days, depending on the diagnostic criteria applied. At least 10% of infants with UTI showed abnormalities on kidney ultrasound [Table 2]. Conclusion There exists a large variation in UTI prevalence according to different diagnostic criteria. Abnormal urinalysis with presence of nitrites were frequently associated with UTI of high CFU count. High resistance to 3GC among gram negative bacilli was concerning and carried an impact on the appropriate empirical treatment choice.

Genetic and biochemical characterization of OXA-1186, a novel OXA-198-type carbapenemase hydrolysing cephalosporins in Citrobacter freundii.

This study described OXA-1186, a novel carbapenemase related to OXA-198 carbapenemase and produced by a clinical isolate of Citrobacter freundii. WGS was used to characterize the resistome, virulome and plasmid types of the C. freundii 315C8 isolate and to reconstruct the blaOXA-1186-carrying plasmid. Disc diffusion and broth microdilution assays were used to determine MICs. The blaOXA-1186 gene was cloned into plasmid pTOPO and then transformed into Escherichia coli TOP10 or HB4. It was also cloned in pET41b and transformed into E. coli BL21 DE3 for protein purification. Steady-state kinetic parameters were determined on purified OXA-1186. C. freundii 315C8, belonging to ST8, was resistant to penicillins including temocillin and broad-spectrum cephalosporins and displayed reduced susceptibility to carbapenems. It was negative for one of the five main carbapenemases. WGS revealed that the blaOXA-1186 gene encoded a novel carbapenemase that shared 83% amino acid identity with OXA-198. The blaOXA-1186 gene was carried on an IncP6-type plasmid and was embedded within a class 1 integron. Cloning and expression in E. coli revealed that expression of the blaOXA-1186 gene conferred resistance to penicillins, cephalosporins and carbapenems, where it was associated with impaired outer membrane permeability. Kinetic parameters confirmed the hydrolysis of ceftazidime, cefepime and aztreonam, in addition to imipenem and meropenem. Here, we described a novel carbapenemase, OXA-1186, identified in C. freundii. Unlike OXA-198, OXA-1186 is able to hydrolyse broad-spectrum cephalosporins. This carbapenemase was carried on a broad-spectrum IncP6 plasmid identified in other Citrobacter species and non-fermenters.

Recent trends in antibiotic sensitivity and resistance patterns in infected wounds of burns patients presented to a tertiary care hospital.

Objective: To study the recent trends and patterns of antibiotic sensitivity and resistance in infected wounds of burns patient. Study Design: Cross sectional study. Setting: Burns and Plastic Surgery Canter, Peshawar, Pakistan. Period: July 30th to January 30th, 2023. Methods: In this cross sectional study we adopted convenience sampling technique. A total of 75 samples collected from patients fitted to our infected patients criteria and culture and sensitivity tests were performed using standard microbiological techniques. Results: Among the positive infected wound samples, Klebsiella Species were found in 23 (30.7%), Pseudomonas Aeruginosa in 16 (21.3%), Acinetobacter Species in 14(18.7%), Proteus Species in 8(10.7%), Citrobacter species in 5(6.6%), Staph. Aureus in 5(6.6%), Enterobacter species in 3(4%) and E.coli in 1(1.4%) of the positive cultures. Each pathogen showed varying degree of sensitivity and resistance patterns to different antibiotics tested. Conclusion: Klebsiella Species was the most common pathogen in patients with infected burns wounds. Meropenem, imipenem, Doripenem, Piperacillin/Tazobactum, Colistin, and Tigecyclin were found to be effective against the majority of the bacteria. Conversely, most of the bacterial strains exhibited resistance to commonly prescribed antibiotics such as co-amoxiclave, ampicillin, ceftriaxone, ciprofloxacin, cefotaxime and co-trimoxazole.

The Scr and Csc pathways for sucrose utilization co-exist in E. coli, but only the Scr pathway is widespread in other Enterobacteriaceae.

Most Escherichia coli isolates from humans do not utilize D-sucrose as a substrate for fermentation or growth. Previous work has shown that the Csc pathway allows some E. coli to utilize sucrose for slow growth, and this pathway has been engineered in E. coli W strains to enhance use of sucrose as a feedstock for industrial applications. An alternative sucrose utilization pathway, Scr, was first identified in Klebsiella pneumoniae and has been reported in some E. coli and Salmonella enterica isolates. We show here that the Scr pathway is native to an important subset of E. coli phylogroup B2 lineages that lack the Csc pathway but grow rapidly on sucrose. Laboratory E. coli strains derived from MG1655 (phylogroup A, ST10) are unable to utilize sucrose and lack the scr and csc genes, but a recombinant plasmid-borne scr locus enables rapid growth on and fermentation of sucrose. Genome analyses of Enterobacteriaceae indicate that the scr locus is widespread in other Enterobacteriaceae; including Enterobacter and Klebsiella species, and some Citrobacter and Proteus species. In contrast, the Csc pathway is limited mostly to E. coli, some Shigella species (in which csc loci are rendered non-functional by various mutations), and Citrobacter freundii. The more efficient Scr pathway likely has greater potential than the Csc pathway for bioindustrial applications of E. coli and other Enterobacteriaceae using sucrose as a feedstock.

Impact of Prophylactic Antibiotic Use in Ornamental Fish Tanks on Microbial Communities and Pathogen Selection in Carriage Water in Hong Kong Retail Shops.

Antibiotics are routinely added to ornamental fish tanks for treating bacterial infection or as a prophylactic measure. However, the overuse or subtherapeutical application of antibiotics could potentially facilitate the selection of antibiotic resistance in bacteria, yet no studies have investigated antibiotic use in the retail ornamental fish sector and its impact on microbial communities. The present study analyzed the concentrations of twenty antibiotics in the carriage water (which also originates from fish tanks in retail shops) collected monthly from ten local ornamental fish shops over a duration of three months. The antibiotic concentrations were correlated with the sequenced microbial community composition, and the risk of resistance selection in bacteria was assessed. Results revealed that the detected concentrations of tetracyclines were the highest among samples, followed by fluoroquinolones and macrolides. The concentrations of oxytetracycline (44.3 to 2,262,064.2 ng L-1) detected across three months demonstrated a high risk for resistance selection at most of the sampled shops. Zoonotic pathogens (species of Rhodococcus, Legionella, and Citrobacter) were positively correlated with the concentrations of oxytetracycline, tetracycline, chlortetracycline, and enrofloxacin. This suggests that antibiotic use in retail shops may increase the likelihood of selecting for zoonotic pathogens. These findings shed light on the potential for ornamental fish retail shops to create a favorable environment for the selection of pathogens with antibiotics, thereby highlighting the urgent need for enhanced antibiotic stewardship within the industry.

Emergence of OXA-48-like producing Citrobacter species, Germany, 2011 to 2022.

BackgroundCarbapenemase-producing Enterobacterales are a public health threat worldwide and OXA-48 is the most prevalent carbapenemase in Germany and western Europe. However, the molecular epidemiology of OXA-48 in species other than Escherichia coli and Klebsiella pneumoniae remains poorly understood.AimTo analyse the molecular epidemiology of OXA-48 and OXA-48-like carbapenemases in Citrobacter species (spp.) in Germany between 2011 and 2022.MethodsData of 26,822 Enterobacterales isolates sent to the National Reference Centre (NRC) for Gram-negative bacteria were evaluated. Ninety-one Citrobacter isolates from 40 German hospitals harbouring bla OXA-48/OXA-48‑like were analysed by whole genome sequencing and conjugation experiments.ResultsThe frequency of OXA-48 in Citrobacter freundii (CF) has increased steadily since 2011 and is now the most prevalent carbapenemase in this species in Germany. Among 91 in-depth analysed Citrobacter spp. isolates, CF (n = 73) and C. koseri (n = 8) were the most common species and OXA-48 was the most common variant (n = 77), followed by OXA-162 (n = 11) and OXA‑181 (n = 3). Forty percent of the isolates belonged to only two sequence types (ST19 and ST22), while most other STs were singletons. The plasmids harbouring bla OXA‑48 and bla OXA-162 belonged to the plasmid types IncL (n = 85) or IncF (n = 3), and plasmids harbouring bla OXA‑181 to IncX3 (n = 3). Three IncL plasmid clusters (57/85 IncL plasmids) were identified, which were highly transferable in contrast to sporadic plasmids.ConclusionIn CF in Germany, OXA-48 is the predominant carbapenemase. Dissemination is likely due to distinct highly transmissible plasmids harbouring bla OXA‑48 or bla OXA-48-like and the spread of the high-risk clonal lineages ST19 and ST22.

Post-Transplant Fecal Carriage of Antibiotic Resistant and B-Lactamases-Producing Enterobacteriales among Renal Transplant Recipients.

The intestinal colonization and transmission of antibiotic-resistant Enterobacteriales to renal transplant recipients may pose a threat to them because they are profoundly immunocompromised and vulnerable to infection. Hence, it is crucial to identify these antibiotic-resistant fecal Enterobacteriales harboring high-risk populations. The objective of this study was to determine antibiotic resistance as well as β-lactamases production in fecal Enterobacteriales among renal transplant recipients. The stool samples, one collected from each transplant recipient, were processed for isolation and identification of Enterobacteriales and were tested for their antibiotic susceptibility, extended-spectrum β-lactamase, and metallo-β-lactamase production by standard methods. A total of 103 Enterobacteriales comprising of Escherichia coli (86.4%), Klebsiella species (11.7%), and Citrobacter species (1.9%) were isolated and more than 60% of the E. coli were found resistant to ceftazidime and ciprofloxacin and around half of the Klebsiella species were resistant to ceftazidime and fluroquinolones. Theextended-spectrum β-lactamase production was seen in 3.4% and 8.3% and metallo-β-lactamase production in 24.7% and 33.3% of E. coli and Klebsiella species, respectively. The high proportion of β-lactamase-producers were resistant to piperacillin-tazobactam, meropenem, gentamicin, and amikacin than β-lactamases non-producers. Since the antibiotic resistance is higher in fecal Enterobacteriales, eachrenal transplant recipient should be screened for these highly resistant intestinal colonizers after transplantation in order to prevent infections and toreduce the rate of transplant failure due to infections.

Isolation and Identification of Bacterial Flora from Foot Lesions of Asian Elephants (Elephas maximus)

The present study was undertaken for the isolation and identification of the bacterial agents present in the foot lesions of captive elephants. A total of 78 samples were collected from various foot lesions of 46 captive elephants and subjected to bacterial culture. Sixteen of these collected samples did not show any bacterial growth in any type of media. The remaining 62 samples had 155 isolates; 94 (60.6%) of them were Gram negative bacteria, and the rest 61 (39.3%) isolates were Gram positive bacteria. Among the 155 isolates, they comprised of E. coli 63 (40.6%), Bacillus species 25 (16.1%), Pseudomonas species 18 (11.6%), 36 (23.2%), Staphylococcus species, Citrobacter species 3 (1.9%) and Enterobacter species 14 (9.03%). The study highlights the microbiological fauna of foot lesions, emphasizing the prevalence of Gram-negative bacteria and underscoring the need for periodic health screening and targeted interventions for captive elephants’ welfare.

Hygienic Practices of Vendors and Their Contribution to Coliform, Salmonella, and Shigella Bacteria of Raw Milk at Asella Town, Oromia, Ethiopia.

Coliform, Salmonella, and Shigella are among the most encountered bacteria in raw milk. This study is aimed at determining the extent of coliform, Salmonella, and Shigella bacteria in raw milk and vendor hygiene practices at Asella town, Oromia Regional State, Ethiopia, from March 1 to 30, 2022. In this study, 210 milk vendors were included; each vendor provided a 50 ml sample of raw milk. Bacteria were isolated and identified using standard bacteriological techniques. Data were entered and analyzed using EPI info version 7 and SPSS version 22, respectively. A binary logistic regression model was applied to determine the factors associated with bacterial contamination of raw milk. The total contamination percentage of raw milk was 50 (23.8%) (95% CI: 18.1-29.5%). The predominant bacteria identified were coliform 43 (20.5%) followed by Salmonella species 7 (3.3%). Among coliforms, the predominant bacteria were Citrobacter species 15 (34.9%) followed by Enterobacter species 11 (25.6%), Escherichia coli and Serratia species each 6 (14%), and Klebsiella species 5 (11.6%). However, no Shigella was isolated in this study. Not having the habit of washing cow teats (p < 0.0001), the habit of washing teats with tap water (p < 0.0001), not having separate cloth during milking (p < 0.0001), not having a practice of testing milk for bacterial contamination (p = 0.027), and not having separate vending environment (p = 0.039) were significantly associated with bacterial contamination of raw milk. The percentage of bacterial contamination of milk was found to be high. Participants without a habit of washing cow teats, a habit of washing milk utensils with only tap water, and not having separate vending environments were associated factors for bacterial contamination of raw milk. Milk vendors are advised to develop the habit of washing teats before milking, avoid washing teat/milk utensils only with tap water, and have a separate vending environment.

Citrobacter enshiensis sp. nov., isolated from seleniferous soil.

Two Gram-stain-negative, facultative anaerobic, rod-shaped bacterial strains, S171T and S2-9, were isolated from seleniferous soil in China. Comprehensive phylogenetic analyses based on 16S rRNA genes, multilocus sequences and whole genome sequences indicated that the two strains belonged to the genus Citrobacter. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of strains S171T and S2-9 with the closest relative Citrobacter koseri NCTC 10786T were 83.6-83.7% and 27.7-27.8 %, respectively, which were below the species cutoff values. The ANI and dDDH values between the two strains were 97.9% and 84.8 %, respectively. The biochemical characteristics revealed that selenite tolerance, H2S and indole production, arginine dihydrolase, ornithine decarboxylase, as well as acid production from carbon sources such as d-sorbitol and arbutin are distinctive features of the two strains. Based on these results, strain S171T and strain S2-9 represent a novel species of the genus Citrobacter, for which the name Citrobacter enshiensis sp. nov. is proposed, with strain S171T (=GDMCC 1.3637T=JCM 35851T) as the type strain. The genome size of strain S171T was 4.92 Mb with a G+C content of 52.6 mol%. The genome size of strain S2-9 was 4.89 Mb with a G+C content of 52.6 mol%.

Influence of age, socioeconomic status, and location on the infant gut resistome across populations

ABSTRACT Antibiotic resistance is a growing global concern, with many ecological niches showing a high abundance of antibiotic resistance genes (ARGs), including the human gut. With increasing indications of ARGs in infants, this study aims to investigate the gut resistome profile during early life at a wider geographic level. To achieve this objective, we utilized stool samples data from 26 studies involving subjects aged up to 3 years from different geographical locations. The 32,277 Metagenome Assembled Genomes (MAGs) previously generated from shotgun sequencing reads from these studies were used for resistome analysis using RGI with the CARD database. This analysis showed that the distribution of ARGs across the countries in our study differed in alpha diversity and compositionally. In particular, the abundance of ARGs was found to vary by socioeconomic status and healthcare access and quality (HAQ) index. Surprisingly, countries having lower socioeconomic status and HAQ indices showed lower ARG abundance, which was contradictory to previous reports. Gram-negative genera, including Escherichia, Enterobacter, Citrobacter, and Klebsiella harbored a particularly rich set of ARGs, which included antibiotics that belong to the Reserve, Access or Watch category, such as glycopeptides, fluoroquinolones, sulfonamides, macrolides, and tetracyclines. We showed that ARG abundance exponentially decreased with time during the first 3 years of life. Many highly ARG-abundant species including Escherichia, Klebsiella, Citrobacter species that we observed are well-known pathobionts found in the infant gut in early life. High abundance of these species and a diverse range of ARGs in their genomes point toward the infant gut, acting as an ARG reservoir. This is a concern and further studies are needed to examine the causal effect and its consequences on long-term health.

Pediatric Citrobacter Urinary Tract Infections: A Case Report Highlighting Emerging Trends

Urinary tract infections (UTIs) caused by Citrobacter species in pediatric patients present a unique and infrequently reported scenario in clinical practice. This case report delves into the clinical presentation, diagnostic challenges, treatment modalities, and overall management of a pediatric UTI caused by Citrobacter. Through a literature review, it becomes evident that while Citrobacter infections are more commonly observed in adults, especially the elderly population, recent studies signal a rising trend in pediatric cases globally. Noteworthy findings from published cases underscore the diverse clinical manifestations and associated challenges. We present the case of a 1-month-old male who presented with feeding difficulties and irritability, subsequently diagnosed with a UTI caused by Citrobacter koseri. Despite lacking typical risk factors or symptoms associated with Citrobacter UTIs, the patient demonstrated a favorable response to antibiotic therapy. This case stresses the evolving nature of Citrobacter infections in the pediatric population and emphasizes the importance of vigilance in recognition and management. Further research is warranted to better understand this emerging trend and its implications for pediatric care.

Antibiogram of Bacteria Isolated from Bloodstream Infection-Suspected Patients at the University of Gondar Comprehensive Specialized Hospital in Northwest Ethiopia: A Retrospective Study.

Bacterial bloodstream infections (BSIs) are the leading cause of sepsis-related morbidity and mortality worldwide. The emergence and spread of antimicrobial resistance (AMR) in bacteria is also a growing global concern. As a result, data on bacterial profile and their antibiogram are essential for strategies to contain drug resistance, improve the quality of patient care, and strengthen health systems. Retrospective data from bacteriological results of blood samples of BSI-suspected patients from 2018 to 2021 were collected using a data collection sheet. Standard bacteriological techniques were followed during sample collection, culture preparation, bacterial identification, and antibiotic susceptibility testing (AST). We used Epi Info version 7 to enter and clean the data and then exported it to SPSS version 26 for analysis. Logistic regression models were used to measure the association between variables. A p value <0.05 with a 95% confidence interval was considered as statistically significant. Of the total 2,795 blood culture records, 455 (16.3%) were culture positive for bacteria, with Klebsiella pneumoniae (26%) and Staphylococcus aureus (24.6%) being the leading isolates. The isolates were highly resistant to common antibiotics, with more than 80% of them being resistant to ceftriaxone and penicillin. Moreover, about 43% of isolates were multidrug resistant (MDR), with Klebsiella pneumoniae (65.5%), Acinetobacter species (56.7%), and Citrobacter species (53.8%) being the most common MDR isolates. Age and diagnosis year were significantly associated with the presence of bacterial BSIs (p value <0.05). Bacterial BSI and AMR were growing concerns in the study area. Bacteremia was more common in children under the age of five, and it decreased as the patient's age increased. The alarming rate of AMR, such as MDR blood isolates, calls for periodic and continuous monitoring of antibiotic usage in the study area.

Isolation and Antimicrobial Resistance Patterns of Bacterial Pathogens from Community-Acquired Pneumonia at Adama Hospital Medical College, Adama, Ethiopia.

Community-acquired pneumonia (CAP) is a major cause of morbidity and mortality worldwide. It also contributes significantly to hospital admissions, particularly in low-income countries such as Ethiopia, where it accounts for major public health problems. This could be attributed to the increasing prevalence of antibiotic-resistant pathogens in CAP patients. This study aimed to identify and assess the antibiotic resistance patterns of bacterial isolates from CAP patients at the Adama Hospital Medical College in Adama City, Ethiopia. A cross-sectional study was conducted from November 10, 2022, to November 30, 2023. Demographic, clinical data, and sputum samples were collected from patients with CAP (n = 369). Sputum samples were subjected to standard microbiological procedures, including culture, Gram staining, and a panel of different biochemical tests for the identification of pathogenic bacterial isolates. The Kirby-Bauer disc diffusion method was used for drug susceptibility testing. Descriptive statistics were computed by using SPSS (version 26). Of the 369 patients with CAP, bacterial pathogens were identified in 31.7% (n = 117, 95% CI: 27.0%-36.7%). The most common isolates were Moraxella catarrhalis (n = 15; 12.8%), Staphylococcus aureus (n = 15; 12.8%), Klebsiella pneumoniae (n = 12; 10.3%), Escherichia coli (n = 11; 9.4%), Pseudomonas aeruginosa (n = 11; 9.4%), Enterobacter species (n = 11; 9.4%), and Citrobacter species (n = 11; 9.4%). Among the identified isolates, resistance rates were high in Enterobacteriaceae, followed by Gram-positive bacteria, and non-Enterobacteriaceae. Overall, 68 (58.1%) of the identified bacterial isolates were multidrug resistant (MDR), with K. pneumoniae accounting for the highest proportion of multidrug resistant isolates (91.7%), while P. aeruginosa accounted for the lowest proportion (9.1%) of MDR isolates. This study revealed a high prevalence (31.7%) of bacterial pathogens in CAP patients and higher (58.1%) MDR bacterial pathogens. Therefore, regular surveillance and monitoring systems are warranted for assessing predominant pathogens and antibiotic resistance patterns.

Extended Spectrum Beta Lactamase Profile of Citrobacter Species Isolated from Various Samples in the North East Coast of Tamil Nadu, India: A Cross-sectional Study

Introduction: Citrobacter species play a significant role in causing hospital-acquired infections, especially those affecting the urinary and respiratory systems, and they are commonly present in faeces. Healthcare systems are facing a major challenge due to the rise of antibiotic-resistant Gram-negative infections resistant to antibiotics. Aim: To identify the genotypic characterisation of the resistant gene blaTEM-1 in Citrobacter spp. obtained from a range of clinical samples. This investigation seeks to provide insights into the patterns of antibiotic resistance exhibited by these bacteria. Materials and Methods: This cross-sectional study was conducted between August 2021 and February 2022. Preliminary examinations included screening as well as confirmatory tests for Extended Spectrum Beta Lactamase (ESBL) production, which were confirmed by the combination disk method and double disc synergy test. Genotypic detection of the blaTEM-1 gene was done using the Polymerase Chain Reaction (PCR) technique. Demographic parameters like gender and age were assessed. Statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) Software version 21.0. Results: Citrobacter koseri (66 isolates, 54.5%) was found to be the predominant species among the Citrobacter spp., followed by Citrobacter freundii (55 isolates, 45.5%). Urine samples were the primary source of Citrobacter spp. isolates, comprising 52 isolates (43%) of the total. In this study, the prevalence of ESBL producers was reported to be 49 isolates (77.8%) identified as ESBL producers. Tigecycline demonstrated a 100% effectiveness rate, followed by Piperacillin-Tazobactam (96% sensitivity) and Amikacin (95% sensitivity). Out of the 20 Citrobacter spp. isolates that tested positive for ESBL, 15 isolates (75%) were found to be positive for blaTEM-1. Conclusion: The results of this study provide insight into the changing patterns of antibiotic resistance in Citrobacter spp., with particular emphasis on ESBL profiles. Thus, it is imperative to implement intervention techniques to reduce the ongoing selection and spread of these more resistant bacteria, as well as efficient infection-control measures to manage epidemics. These results advance the comprehension of antibiotic resistance patterns and guide initiatives to combat the increasing threat of antibiotic resistance.

Antibiogram of Bacterial Isolated from Selected Borehole Water as Source of Drinking Water in Kakata, Margibi, Liberia.

Water is acquired from rain, bodies of water (rivers, ponds), and groundwater. Although water can include inappropriate chemicals (from natural sources and agricultural operations), the most serious threat to human wellness is fecal pollution of water supplies, which causes water-borne illnesses. Borehole water samples from seven places in Kakata, Margibi County, Liberia were analyzed for microbial load using standard microbiological procedures. The susceptibility of the microorganisms isolated to commercial antibiotics was also determined. The overall aerobic plate count ranged from 1.9×10 to 5.4×10² cfu/ml, whereas the total coliform count varied from 0.6×10 to 1.8×10 cfu/100ml. The fecal coliform count was low in most samples and entirely absent in one of the research locations. Microbial numbers significantly differed (p=0.05) among the regions investigated. The predominant bacteria isolated were Bacillus species, Enterococcus species, Citrobacter species, Salmonella species, Escherichia coli, and Staphylococcus aureus. The antibiogram performed using the disc diffusion technique revealed that Staphylococcus aureus was most susceptible to streptomycin and least sensitive to ciprofloxacin, while Enterococcus species was most sensitive to septrin but resistant to several of the antibiotics tested. Escherichia coli was the most sensitive to septrin and the least to ciprofloxacin. Ciprofloxacin inhibited Citrobacter species similarly to nalidixic acid. Salmonella species were very vulnerable to nalidixic acid and augmentin, however Bacillus species were resistant to all antibiotics tested, which raises public health concerns.

Identification of antibiotic-resistant pathogens and virulence genes in Escherichia coli isolates from food samples in the Dhaka University campus of Bangladesh.

The presence of antibiotic-resistant pathogens in food is a serious public health concern nowadays. This study focuses on the isolation and characterization of potentially pathogenic Escherichia coli and antimicrobial-resistant pathogens in chicken curry and potato smash samples collected from the canteens and cafeteria of Dhaka University in Bangladesh. Isolates were identified by their cultural, morphological, and biochemical tests (motility indole urease test, Kliger's iron agar test, catalase test, oxidase test, methyl red and Voges-Proskauer tests). The antibiotic susceptibility test was done by the disk diffusion method. The range of total bacterial count in the potato smash and chicken curry samples was from 1.4 × 104 to 1.6 × 108 CFU/g and from 2.4 × 103 to 2.6 × 106 CFU/g, respectively. Escherichia coli, Salmonella, Vibrio, Klebsiella, Citrobacter, Enterobacter, Proteus, Clostridium, Staphylococcus, Streptococcus, Micrococcus, Bacillus, and Sarcina strains were isolated in both samples. Isolates were highly resistant to ampicillin (90.90%) followed by colistin (52.27%), azithromycin (27.27%), and tetracycline 25%. Proteus species had the highest rate of multiple antibiotic resistance (MAR; 62.5%), followed by Citrobacter species (50%). The isolated E. coli strains were further analyzed through PCR assay to detect virulent genes (EPEC: eaeA 229 bp, bfpA 450 bp, ETEC elt 322 bp, EHEC hylA 534 bp, and EIEC ial 320 bp). One E. coli isolate had the eaeA target gene under EPEC pathotypes. Escherichia coli, as a fecal indicator, may indicate fecal contamination or poor and unhygienic food handling. The findings recommend further investigations to identify potential mechanisms of contamination and preventive measures to improve the food safety level in the canteens and restaurants.

The phylogenomic landscape of extended-spectrum β-lactamase producing Citrobacter species isolated from surface water

BackgroundCitrobacter species are Gram-negative opportunistic pathogens commonly reported in nosocomial-acquired infections. This study characterised four Citrobacter species that were isolated from surface water in the North West Province, South Africa.ResultsPhenotypic antimicrobial susceptibility profiles of the isolates demonstrated their ability to produce the extended-spectrum β-lactamase (ESBL). Whole genomes were sequenced to profile antibiotic resistance and virulence genes, as well as mobile genetic elements. In silico taxonomic identification was conducted by using multi-locus sequence typing and average nucleotide identity. A pangenome was used to determine the phylogenomic landscape of the Citrobacter species by using 109 publicly available genomes. The strains S21 and S23 were identified as C. braakii, while strains S24 and S25 were C. murliniae and C. portucalensis, respectively. Comparative genomics and sequenced genomes of the ESBL-producing isolates consisted of n = 91; 83% Citrobacter species in which bla-CMY−101 (n = 19; 32,2%) and bla-CMY−59 (n = 12; 38,7%) were prevalent in C. braakii, and C. portucalensis strains, respectively. Macrolide (acrAB-TolC, and mdtG) and aminoglycoside (acrD) efflux pumps genes were identified in the four sequenced Citrobacter spp. isolates. The quinolone resistance gene, qnrB13, was exclusive to the C. portucalensis S25 strain. In silico analysis detected plasmid replicon types IncHI1A, IncP, and Col(VCM04) in C. murliniae S24 and C. portucalensis S25, respectively. These potentially facilitate the T4SS secretion system in Citrobacter species. In this study, the C. braakii genomes could be distinguished from C. murliniae and C. portucalensis on the basis of gene encoding for cell surface localisation of the CPS (vexC) and identification of genes involved in capsule polymer synthesis (tviB and tviE). A cluster for the salmochelin siderophore system (iro-BCDEN) was found in C. murliniae S24. This is important when it comes to the pathogenicity pathway that confers an advantage in colonisation.ConclusionsThe emerging and genomic landscapes of these ESBL-producing Citrobacter species are of significant concern due to their dissemination potential in freshwater systems. The presence of these ESBL and multidrug-resistant (MDR) pathogens in aquatic environments is of One Health importance, since they potentially impact the clinical domain, that is, in terms of human health and the agricultural domain, that is, in terms of animal health and food production as well as the environmental domain.

A brief insight into Citrobacter species - a growing threat to public health

Citrobacter spp. are Gram-negative, non-spore forming, rod-shaped, facultative anaerobic bacteria from the Enterobacteriaceae family often found in soil, sewage, sludge, water, food, and the intestinal tracts of animals and humans. Several members of Citrobacter spp. especially C. freundii, C. koseri, C. braakii are frequently detected in newborn illnesses, urinary tract infections, and patients with severe underlying conditions, including hypertension, diabetes, cancer, and respiratory infections, or those who are immunocompromised. Strains of Citrobacter spp. can spread vertically or horizontally from carriers or other hospital sources and thus cause nosocomial infections in hospital settings. A total of 19 Citrobacter genomospecies have been recognized based on genomics. It has been noted that the Citrobacter genus acquired antimicrobial resistance and virulence, including invasion, colonization, biofilm formation, and toxin production. The recent emergence and spread of antimicrobial resistance to β-lactams, carbapenems, fluoroquinolones, aminoglycosides, and colistin in Citrobacter spp. through chromosomal and plasmid-mediated resistance limits the empiric treatment options. Therefore, combination therapy involving costly and potentially hazardous antibiotics poses significant challenges in treating Citrobacter infections. Here we summarized the nomenclature of Citrobacter spp., clinical manifestations, epidemiology, pathogenesis, antibiotic resistance mechanisms, and treatments from various clinical samples. This review will expand our knowledge of the genomics and epidemiology of Citrobacter spp., enabling improved control of infections and the spread of these organisms.

Anitmicrobial Susceptibility to Microoranisms in Hematological Malignancies; A Need to Review Institutional Protocols

Abstract Introduction Febrile neutropenia is a medical emergency in patients with hematological malignancies. The severity of neutropenia and the duration of infection have an important implication on primary treatment outcome. Previously assessed institutional review revealed gram negative bacteria to be the most common microorganisms, and leading cause of febrile neutropenia. However, the predominance of gram positive bacteria had also increased in later past years [1]. In high risk patients, infections caused by multidrug resistant bacteria worsen treatment complications and thus at times empirical use of antibiotics like colomycin is required; otherwise the prognosis may be jeopardized [2]. Regular surveillance of local flora and susceptibility pattern of antimicrobial is must to elude the antimicrobial resistance. Objective The study was conducted to evaluate the prevalence of microorganisms and to observe the sensitivity pattern of antimicrobials as an institutional protocol to establish antimicrobial policies. Material and methods A cross sectional study was conducted at National Institute of blood diseases and bone marrow transplantation, PECHS campus from August 2021 - January 2022. Ethical approval was taken from research committee prior to the study and informed consent was taken from the patients. Febrile neutropenia was defined as a single reading of oral temperature of ≥38 °C on two or more occasions in 12 h in the presence of absolute neutrophil count of less than 1000cells/mm. Blood cultures were performed using the BACTEC blood culture system. Organisms were identified according to routine bacteriological procedures and disc diffusion method was used for interpreting antibiotic susceptibility. Data was analyzed by SPSS version 23.0. Frequencies and percentages were calculated for categorical variable and mean (standard deviation) was computed for quantitative variables. Association between categorical variables was observed using the chi-square test or Fisher’s exact test. P value of &amp;lt;0.05 was considered statistically significant. Results A total of 310 cultures taken from blood (37.4%), peripheral line (4.2%), hickman line (8.1%), red line (2.6%), pus (7.1%), sputum (9.7%) and urine (31%) samples were observed. Out of total 213 (69%) were found to be gram negative and 97 (31%) were gram positive. Gram negative were mostly reported in blood cultures 61 (20%) while gram positive was found in urine cultures 80 (26%). E.coli (40.8%) was the most prevalent among the gram negative microorganisms followed Klebsiella pneumonae (16.9%), Pseudomonas species (11.7%), Pseudomonas aeruginosa (11.3%), Burkholderia cepacia (7%), Enterobacter species (3.3%), Moraxella species (3.3%), Proteus mirabilis (2.8%), Salmonella typhi (1.4%), Acinetobacter species (0.9%) and Citrobacter species (0.5%). In gram negative organisms, Acinetobacter species, Burkholderia cepacia, Citrobacter species and Moraxella species were identified substantially which were not previously prevalent. In gram positive microorganisms Staphylococcus epidermidis (55.3%) was more prevalent, followed by Enterococcus species (19%), Micrococcus species (16%), Streptococcus species (6%), Staphylococcus aureus (3.7%), from which Micrococcus species was reported for first time. Sensitivity of meropenem, amikacin and colistin was higher in gram negative while the sensitivity of fosfomycin, and linezolid was found in gram positive isolates The association of sensitivity and resistance with gram negative and positive isolates was found statistically significant with amikacin, vancomycin, fosfomycin and ciprofloxacin (p=&amp;lt;0.05). Conclusion Gram negative isolates were found prevalent in our study. The sensitivity of meropenem, amikacin and colistin was high than other regimens in gram negative while the sensitivity of fosfomycin, and linezolid was found in gram positive isolates. Few emerging isolates were observed in the study as well. The regular review of microbial pattern and susceptibility evaluation is imminent for prevention of microbial resistance and assessment of institutional practices.