Acinetobacter Species Research Articles

Examining the Frequency of Selected Genes Involved in Biofilm Formation in Clinical Isolates of Acinetobacter Baumannii

Introduction: Acinetobacter baumannii, a non-fermenting Gram-negative coccobacillus, exhibits high resistance to antimicrobial compounds. Biofilm formation is a crucial feature in many Acinetobacter species, contributing to their antibiotic resistance. The present study aimed to investigate the prevalence of ompA, csuA, bap and pgaB genes in clinical isolates of Acinetobacter baumannii with biofilm formation ability. Methods: In this cross-sectional study, 49 isolates of Acinetobacter baumannii were collected from patients hospitalized in the health centers of Borujerd City. Acinetobacter baumannii isolates were confirmed by biochemical tests. In these isolates, the biofilm production ability was investigated by microtitreplate method. Then, using PCR method and specific primers, ompA, csuA, bap and pgaB genes were identified.The collected data were analyzed descriptively and analytically using SPSS version 16 software. Data analysis was done with Chi-square test, Fisher's exact test, and P<0.05 was considered as the basis of significance. Results: The presence of ompA, csuA, bap, and pgaB genes was detected in 87%, 92%, 98%, and 100% of the isolates, respectively. Additionally, the microtitreplate method revealed that biofilm formation was strong in 3 isolates (6%), moderate in 17 isolates (35%), and weak in 29 isolates (59%). Conclusion: The prevalence of genes associated with biofilm formation in Acinetobacter baumannii isolates was high. This suggests that the studied isolates possess a significant ability to form biofilm structures.

RESIST ACINETO test for the rapid detection of NDM and OXA acquired carbapenemases directly from blood culture in Acinetobacter species.

The incidence of bloodstream infections with carbapenem-resistant Acinetobacter baumannii (CRAB) could be very high in some countries such as the Balkans or Southeast Asia. In case of positive blood cultures with Gram-negative bacteria, the use of the RESIST ACINETO test could prove highly beneficial for the rapid identification of these imipenem-resistant bacteria and their antibiotic resistance mechanisms. In addition, it is now well established that New-Delhi Metallo-beta-lactamase (NDM) carbapenemase-producing isolates can have increased MICs of cefiderocol, which is an alternative treatment for these infections. This test may also allow the optimization of treatment based on the type of carbapenemase present. Finally, the RESIST ACINETO test is a rapid, easy-to-use, and cost-effective assay that demonstrates excellent performance in detecting the major acquired carbapenemases present in the Acinetobacter species.

Bacterial Genomics for National Antimicrobial Resistance Surveillance in Cambodia.

Antimicrobial resistance (AMR) surveillance in low- and middle-income countries (LMICs) often relies on poorly resourced laboratory processes. Centralized sequencing was combined with cloud-based, open-source bioinformatics solutions for national AMR surveillance in Cambodia. Blood cultures growing gram-negative bacteria were collected at six Cambodian hospitals (January 2021 - October 2022). Isolates were obtained from pure plate growth and shotgun DNA sequencing performed in-country. Using public nucleotide and protein databases, reads were aligned for pathogen identification and AMR gene characterization. Multilocus sequence typing was performed on whole genome assemblies and haplotype clusters compared against published genomes. Genes associated with acquired resistance to fluoroquinolones were identified in 59%, TMP/SMX in 45%, and aminoglycosides in 52% of 715 isolates. Extended-spectrum beta-lactamase encoding genes were identified in 34% isolates, most commonly blaCTX-M-15, blaCTX-M-27, and blaCTX-M-55 in E. coli sequence types 131 and 1193. Carbapenemase genes were identified in 12% isolates, most commonly blaOXA-23, blaNDM-1, blaOXA-58 and blaOXA-66 in Acinetobacter species. Phylogenetic analysis revealed clonal strains of A. baumannii, representing suspected nosocomial outbreaks, and genetic clusters of quinolone-resistant typhoidal Salmonella and ESBL E. coli cases suggesting community transmission. With accessible sequencing platforms and bioinformatics solutions, bacterial genomics can supplement AMR surveillance in LMICs. Research was supported by the National Institute of Allergy and Infectious Diseases and the Bill and Melinda Gates Foundation [OPP1211806].

Antimicrobial resistance patterns in patients admitted in a medical intensive care unit at Rawalpindi, Pakistan

Background & objective: The prevalence of antibiotic resistance has increased with the excessive use of antibiotics in our country. We aimed to examine the patterns of antibiotic resistance in different organisms found in patients admitted to our Medical Intensive Care Unit (MICU). Additionally, the study sought to determine the relationship between the pathogen causing the infection and the outcome of the patients. Methodology: This retrospective observational cross-sectional study was conducted in the MICU of Farooq Hospital affiliated with Akhtar Saeed Medical College, Rawalpindi, Pakistan, from January 01, 2024 to March 31, 2024. The data was collected from the medical records of adult patients (aged 12-79 y) who were admitted to the MICU during the study period. SPSS 29 was used for data analysis. Analyzed data included information on demographics, culture results, and antibiotic resistance patterns. We included culture results of blood, urine, and Foley catheter tip. The final disposal of the patients was noted and linked to the pathogen responsible for the disease. Results: The study involved 104 patients admitted to the MICU. The average duration of stay was 5.36 days, the average age was 51.17 ± 18.47 y, and 61.53% of the patients were male. The primary diagnoses were urinary tract infection (18.22%) and sepsis (15.76%). Pre-existing conditions included diabetes mellitus (24.15%) and hypertension (23.59%). Klebsiella pneumoniae was the predominant organism, followed by E. coli. Overall, 58.52% of the isolates showed resistance to the tested antibiotics. Specific drugs, such as ceftazidime and amoxicillin-clavulanic acid, demonstrated absolute resistance (100%), while vancomycin and tigecycline showed no resistance. In this study, patients with infections caused by Enterobacter, Enterococcus faecalis, Proteus, and Salmonella spp. had discharge rates of 100%. In contrast, infections caused by Candida, Acinetobacter species, and Klebsiella pneumoniae were associated with 100%, 75%, and 48.5% mortality rates, respectively. Conclusion: The study revealed a significant prevalence of antibiotic resistance among microorganisms in our Medical Intensive Care Unit. Klebsiella pneumoniae was the predominant organism, and distinct bacterial infections were linked to diverse patient outcomes. Abbreviations: MDR - multidrug resistance; MICU - Medical Intensive Care Unit; MRSA - methylene resistant S. aureus XDR - extensively drug resistant Keywords: Antibiotic, Resistance, Pakistan, Intensive Care Units. Citation: Bacha MF, Sayed TM, Maqsood J, Noaman M, Aslam M, Noureen F, Ikram N. Antimicrobial resistance patterns in patients admitted in a medical intensive care unit at Rawalpindi, Pakistan. Anaesth. pain intensive care 2024;28(4):727−731; DOI: 10.35975/apic.v28i4.2521 Received: June 10, 2024; Reviewed: June 21, 2024; Accepted: July 15,2024

Specification of Rhizospheric Characteristics of Some Bacteria Identified by MALDI TOF MS from Agricultural Soils in Kirsehir Province (Akçakent and Çiçekdağı) Districts

The rhizosphere are site of plant-microorganism interaction, and have critical impotance in events like nutrient supply, the production of compounds that support plant growth and phytopathogen protection. This study reports 52 bacteria isolated from 5 different plant rhizospheres (Hordeum vulgare, Avena sativa, Cicer arietinum, Helianthus annuus, and Phaseolus vulgaris) of two agricultural districts of Kırşehir (Akçakent and Çicekdağı regions) in Türkiye. Morphological, biochemical, plant growth-promoting characteristics (including production of indole-3-acetic acid, siderophore, nitrogen fixation, and phosphate solubilization) using MALDI-TOF-MS techniques were used to identify the isolates. Among all isolates, 33 isolate were Gram positive and 19 were Gram negative. Furthermore 40% of them were classified as Bacillus species, 10% belonged to Pseudomonas species, 7% were Acinetobacter species, 4% were Pantoeae species, and 39% other species (Blastomonas, Lysinibacillus, Comamonas, Alcaligenes, Bifidobacterium, Aromatoleum). It was seen that 12 isolates fixed nitrogen, 8 isolates produced dissolved inorganic phosphate, 12 isolates produced siderophores, 9 isolates were produced by IAA, and 14 isolates produced HCN during the screening of plant growth promoting properties. It is concluded that the culture of bacteria living in the rhizosphere are essential to promote soil fertility and sustainable agriculture. Therefore, there is a need to identify and use these strains with plant growth promoting properties in agriculture.

Bloodstream Infections in the Neonatal Intensive Care Unit: A Systematic Review of the Literature.

Bloodstream infections represent a significant concern in neonatal intensive care units (NICUs), constituting a leading cause of morbidity and mortality among neonates. This study aimed to elucidate the etiology, prevalence, and antimicrobial resistance patterns of bloodstream infections in NICU settings. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines using the PubMed database to source relevant studies published between 2019 and 2023. Keywords related to bloodstream infections, neonates in NICUs, pathogens, resistance, and susceptibility were employed. Out of the 73 identified articles, eight met the inclusion criteria. Findings revealed a predominance of late-onset sepsis in hospitalized neonates, with Escherichia coli, Klebsiella pneumoniae, coagulase-negative staphylococci, Group B Streptococcus, Acinetobacter species, Serratia marcescens, Staphylococcus aureus, and Enterobacter cloacae being the most commonly isolated pathogens. Antimicrobial susceptibility profiles demonstrated resistance among bacteria to ampicillin, gentamicin, and penicillin, while fungi exhibited resistance to amphotericin B, fluconazole, flucytosine, itraconazole, and voriconazole. These findings underscore the persistent challenge of bloodstream infections in the NICUs, particularly late-onset sepsis, emphasizing the importance of early detection and appropriate antimicrobial therapy in neonatal care management.

Distribution and Molecular Characterization of Clinically Relevant Acinetobacter Species from Selected Freshwater Sources in the Eastern Cape Province, South Africa

Distribution and Molecular Characterization of Clinically Relevant Acinetobacter Species from Selected Freshwater Sources in the Eastern Cape Province, South Africa

Clinical and microbiological features of positive blood culture episodes caused by non-fermenting gram-negative bacilli other than Pseudomonas and Acinetobacter species (2020-2023).

Non-fermenting Gram-negative bacilli (NFGNB) other than Pseudomonas aeruginosa and Acinetobacter baumannii complex are pathogens of interest due to their ability to cause health-care associated infections and display complex drug resistance phenotypes. However, their clinical and microbiological landscape is still poorly characterized. Observational retrospective study including all hospitalized patients presenting with a positive positive blood culture (BC) episode caused by less common NFGNB over a four-year period (January 2020-December 2023). Clinical-microbiological features and factors associated with mortality were investigated. Sixty-six less common NFGNB isolates other than Pseudomonas and Acinetobacter species causing 63 positive BC episodes were recovered from 60 patients. Positive BC episodes were predominantly sustained by Stenotrophomonas maltophilia (49.2%) followed by Achromobacter species (15.9%) that exhibited the most complex resistance phenotype. Positive BC episodes had bloodstream infection criteria in 95.2% of cases (60 out 63), being intravascular device (30.2%) and respiratory tract (19.1%) the main sources of infection. Fourteen-day, 30-day, and in-hospital mortality rates were 6.4%, 9.5%, and 15.9%, respectively. The longer time from admission to the positive BC episode, older age, diabetes, admission due to sepsis, and higher Charlson Comorbidity Index were identified as the main predictors of in-hospital mortality. Positive BC episodes sustained by NFGNB other than Pseudomonas and Acinetobacter species were predominantly sustained by Stenotrophomonas maltophilia and Achromobacter species, having bloodstream infection criteria in the vast majority of cases. Factors that have emerged to be associated with mortality highlighted how these species may have more room in prolonged hospitalisation and at the end of life for patients with chronic organ diseases.

Effect of chemotherapeutic agents on natural transformation frequency in Acinetobacter baylyi.

Natural transformation is the ability of a bacterial cell to take up extracellular DNA which is subsequently available for recombination into the chromosome (or maintenance as an extrachromosomal element). Like other mechanisms of horizontal gene transfer, natural transformation is a significant driver for the dissemination of antimicrobial resistance. Recent studies have shown that many pharmaceutical compounds such as antidepressants and anti-inflammatory drugs can upregulate transformation frequency in the model species Acinetobacter baylyi. Chemotherapeutic compounds have been shown to increase the abundance of antimicrobial resistance genes and increase colonization rates of potentially pathogenic bacteria in patient gastrointestinal tracts, indicating an increased risk of infection and providing a pool of pathogenicity or resistance genes for transformable commensal bacteria. We here test for the effect of six cancer chemotherapeutic compounds on A. baylyi natural transformation frequency, finding two compounds, docetaxel and daunorubicin, to significantly decrease transformation frequency, and daunorubicin to also decrease growth rate significantly. Enhancing our understanding of the effect of chemotherapeutic compounds on the frequency of natural transformation could aid in preventing the horizontal spread of antimicrobial resistance genes.

Physiological Roles of an Acinetobacter-specific σ Factor.

The Gram-negative pathogen Acinetobacter baumannii is considered an "urgent threat" to human health due to its propensity to become antibiotic resistant. Understanding the distinct regulatory paradigms used by A. baumannii to mitigate cellular stresses may uncover new therapeutic targets. Many γ-proteobacteria use the extracytoplasmic function (ECF) σ factor, RpoE, to invoke envelope homeostasis networks in response to stress. Acinetobacter species contain the poorly characterized ECF "SigAb;" however, it is unclear if SigAb has the same physiological role as RpoE. Here, we show that SigAb is a metal stress-responsive ECF that appears unique to Acinetobacter species and distinct from RpoE. We combine promoter mutagenesis, motif scanning, and ChIP-seq to define the direct SigAb regulon, which consists of sigAb itself, the stringent response mediator, relA, and the uncharacterized small RNA, "sabS." However, RNA-seq of strains overexpressing SigAb revealed a large, indirect regulon containing hundreds of genes. Metal resistance genes are key elements of the indirect regulon, as CRISPRi knockdown of sigAb or sabS resulted in increased copper sensitivity and excess copper induced SigAb-dependent transcription. Further, we found that two uncharacterized genes in the sigAb operon, "aabA" and "aabB", have anti-SigAb activity. Finally, employing a targeted Tn-seq approach that uses CRISPR-associated transposons, we show that sigAb, aabA, and aabB are important for fitness even during optimal growth conditions. Our work reveals new physiological roles for SigAb and SabS, provides a novel approach for assessing gene fitness, and highlights the distinct regulatory architecture of A. baumannii.

Prevalence of ESKAPE pathogens and Antibiotic Susceptibility Status in Skin and Soft Tissue Infections from a tertiary care teaching hospital in South India

Background: ESKAPE “(Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter sp.)” pathogens are commonly found in infections affecting the skin and underlying tissues. ESKAPE pathogens often exhibit widespread multidrug resistance in hospitals, contributing significantly to Hospital-acquired infections. ESKAPE pathogen prevalence can combat the vast challenge of Antibiotic Resistance (ABR). Materials and Methods: “The microbiological statistics of ESKAPE infections and sensitivity between January 2020 and October 2022 were extracted from the laboratory records and analysed for the bacterial profile and antibiotic sensitivity pattern”. Results: Out of the 2037 pathogens isolated from Skin and soft tissue infection, 1308 were ESKAPE pathogens accounting for a prevalence of 64.2%. Staphylococcus aureus (n=340/1308; 25.99%) was the predominant pathogen followed by Pseudomonas aeruginosa (n=332/1308; 25.38%). Among Gram-negative isolates, 29.43% exhibited multidrug resistance (MDR). Carbapenemase was found to be a frequent mechanism of resistance, highest among Acinetobacter species (n=99; 64.7%), followed by Klebsiella pneumoniae (n=109; 37.07%). Amp C production was seen most commonly in Enterobacter species (n=93; 61.2%), followed by Klebsiella pneumoniae (n=172; 58.5%) whereas ESBL production was seen in Enterobacter species (n=46; 30.03%). Conclusion: ESKAPE pathogens are critical etiologic agents of Skin and soft infections. Regular studies are vital for evaluating bacterial susceptibility and highlighting the importance of policies to reduce hospital infections and enhance antibiotic prescription oversight. Understanding virulence and resistance markers is critical for tailoring treatment strategies based on local antibiograms and managing related infections.

Multidrug resistant Acinetobacter species – Emergence of a potent pathogen from clinical isolates of tertiary care teaching centre of Central India

Multidrug resistant Acinetobacter species – Emergence of a potent pathogen from clinical isolates of tertiary care teaching centre of Central India

Prevalence, Antimicrobial Susceptibility, and Carbapenem Resistance of Non-baumannii Acinetobacter Species in Three Korean Hospitals

Prevalence, Antimicrobial Susceptibility, and Carbapenem Resistance of Non-baumannii Acinetobacter Species in Three Korean Hospitals

Prevalence, Determinants, and Antibiotic Resistance Patterns of Urinary Tract Infections in Antenatal Women in an Urban Resettlement Colony and Slum in Delhi, India: A Cross-sectional Study

Abstract Background: Urinary tract infection (UTI) is the most common bacterial infection occurring in pregnant women with untreated, recurrent, and inadequately treated bacteriuria accentuating the risk of multiple adverse fetal and maternal health outcomes. The study objective was to determine the proportion of UTIs and their predictors along with antibiotic resistance patterns of causative organisms in pregnant women. Materials and Methods: This cross-sectional study was conducted among 348 pregnant women in an urban resettlement and slum colony. Urine samples were examined through semi-quantitative culture on plated Mac Conkey and blood agar. Antibiotic susceptibility testing was done on Muller Hinton agar using the modified Stokes’ disc diffusion method. Results: At least one symptom related to UTI was reported by 35.7% (95% CI: 30.7-41.1) of the participants. The proportion of pregnant women detected having UTI on urine culture was 7.4% (n = 24, 95% CI: 5.1-10.8) with 13 (54.2%) asymptomatic and 11 (45.8%) symptomatic cases. Overcrowding was a significant predictor of UTI. The most common organisms detected were Escherichia coli (n = 12), Klebsiella pneumoniae (n = 7), Staphylococcus aureus (n = 3), and Acinetobacter species (n = 2). Conclusions: The use of individual toilets and active screening for UTI through culture and sensitivity testing in pregnant women should be promoted in low-resource settings irrespective of symptoms. The initiation of presumptive antibiotic therapy for UTI cases in pregnant women should be restricted to painful micturition due to high false positivity of other symptoms with Nitrofurantoin being a likely preferred drug for empirical administration due to its low resistance pattern among isolated organisms.

Detection of Metallo β-Lactamase in Acinetobacter Species Using Phenotypic Methods with their Antibiotic Resistance Profile in Tertiary Care Hospital

Background: Acinetobacter species are commonly found in nature, in water, and in soil, and also, and they have been isolated from humans and animals. In the hospital setting, Acinetobacter species has emerged as a major opportunistic pathogen, being able to colonize and develop infections in patients. In Acinetobacter species, β-lactamases and outer membrane alterations are likely to function together to impart resistance. Understanding the epidemiology, and resistance mechanism, and for infection management and preventing a potential global health crisis, techniques for identifying Carbapenem-Resistant-Acinetobacter species are essential. Aim: To detect Metallo β-Lactamase (MBL) in Acinetobacter species with their antimicrobial susceptibility pattern. Material and Methods: 100 Acinetobacter species isolates from various clinical samples such as blood, cerebrospinal fluid, sputum, bronchoalveolar lavage, pus, urine, wound swab, and body fluids were included in the study. Phenotypic tests such as, Disc Potentiation test & Modified Hodge test were used to detect the presence of Metallo β-lactamase in imipenem & meropenem-resistant isolates. Results: The highest prevalence of Acinetobacter was found in blood (37%), followed by sputum (31%) and others [pus, urine, ascitic fluid, cerebrospinal fluid (CSF), bronchoalveolar Lavage (BAL), and pleural fluid]. A maximum number of Acinetobacter were isolated from MICU followed by medicine and surgery. The Modified Hodge test yielded the largest percentage of MBL-positive Acinetobacter isolates (67.26%) when compared to the Disc Potentiation test method (50.45%). Conclusion: Early detection of Metallo β-lactamase production is essential for planning appropriate treatment according to the resistance mechanisms of the multi-drug resistant strains, as well as for efficient infection control procedures to prevent the spread of infection.

The Etiologic Organisms, Risk Factors, and Outcomes of Nosocomial Bloodstream Infections in Pediatric Patients

Background Much of the knowledge regarding pediatric healthcare-associated infections is based on studies conducted in adults. Here, we investigated clinical risk factors and etiologic organisms, focusing on antibiotic and antifungal resistance in pediatric patients with nosocomial bloodstream infections (nBSIs) in pediatric intensive care units (PICUs). Methods A retrospective evaluation was conducted on pediatric patients with nBSI in the PICUs of a tertiary referral hospital. Results A total of 69 nBSI episodes in 65 patients were observed during the study period. Of these, a total of 40 (57.97%) were caused by Gram-negative bacteria, 6 (8.7%) by Gram-positive bacteria, and 23 (33.33%) by Candida species. The rankings of Gram-negative bacteria were Klebsiella pneumoniae (37.5%), Acinetobacter baumannii (22.5%), and Serratia marcescens (12.5%). Carbapenem resistance was found to be common among K. pneumoniae (40%) and all Acinetobacter species. Most children (54.41%) had spent >28 days in the PICU at the time of diagnosis of nBSI. The presence of central venous catheters was significantly associated with fungal nBSI (P = 0.047). Conclusions A high rate of antimicrobial resistance was observed among pathogens. A central venous catheter was associated with fungemia in children hospitalized in PICUs. Prolonged hospital stay before the diagnosis of BSI and the use of medical devices were found to be common in fungal infections.

БИОТЕХНОЛОГИЧЕСКИЙ ПОТЕНЦИАЛ НОВЫХ ШТАММОВ УГЛЕВОДОРОДОКИСЛЯЮЩИХ БАКТЕРИЙ

The ingress of oil has a depressing effect on the soil biocenosis, which is enhanced in the presence of other pollutants (heavy metals, chlorides, herbicides), which ultimately leads to the withdrawal of significant land areas (including agricultural ones) from the target turnover. For the bioremediation of such areas, oil-degrading microorganisms are needed that are resistant to additional pollutants, as well as a set of useful properties that increase the efficiency of cleaning and restoring disturbed soils. In this work, three isolates were isolated that actively grew in a liquid medium containing oil. As a result of sequencing the nucleotide sequence of the 16S rRNA gene, it was reliably established that all strains belong to the species Acinetobacter calcoaceticus . The bacteria showed a high oil-oxidizing ability (89.7-97.0%), which was assessed by the degree of destruction of the aliphatic fraction, including in the presence of herbicides based on 2,4-dichlorophenoxyacetic acid (Octapon extra), imazethapyr (Tapir) and tribenuron-methyl ( Special forces) (degree of biodestruction 40.4-54.1%). Microorganisms used aromatic hydrocarbons (including polycyclic ones) as a carbon source. They demonstrated high cell surface hydrophobicity (78-85%) with respect to hexadecane and exhibited emulsifying activity of more than 50%. The bacteria were tolerant to the herbicides Tapir and Spetsnaz in amounts up to 1% volume (mass). The herbicide Octapon extra was more toxic to bacteria - the growth of all strains occurred at its concentration in the medium not higher than 0.5% volume. Microorganisms showed resistance to sodium chloride in an amount of 3.0-5.0% and lead ions (1.00-1.25 g/l). They produced the enzyme lipase and were capable of fixing atmospheric nitrogen and dissolving inorganic phosphate (including in the presence of oil or herbicides). The studied Acinetobacter spp. stimulated the growth of barley (aboveground and underground parts), especially the A. calcoaceticus strain P32 (elongation of shoots and roots by 15.3 and 49.5%, respectively). The data obtained indicate that all three strains have certain prospects for use in the purification of complexly contaminated soils.

Transcriptome analysis of Acinetobacter calcoaceticus HX09 strain with outstanding crude-oil-degrading ability.

Microbial remediation plays a pivotal role in the elimination of petroleum pollutants, making it imperative to investigate the capabilities of microorganisms in degrading petroleum. The present study describes the isolation of a promising strain, Acinetobacter sp. HX09, from petroleum-contaminated water. GC-MS analysis revealed a remarkable removal efficiency for short and medium-chain alkanes, with a rate of approximately 64% after a 7-days incubation at 30 °C. Transcriptome analysis of HX09 exhibited a predominant upregulation in gene expression levels by the induce of crude oil. Notably, genes such as alkane 1-monooxygenase, dehydrogenases and fatty acid metabolic enzymes exhibited fold changes range from 3.16 to 1.3. Based on the alkB gene sequences in HX09, the Phyre2 algorithm generated a three-dimensional structure that exhibited similarity to segments of acyl coenzyme desaturases and acyl lipid desaturases. Furthermore, three biodegradation-related gene clusters were predicted in HX09 based on the reference genome sequence. These findings contribute to our understanding of the hydrocarbon-degrading mechanisms employed by Acinetobacter species and facilitate the development of effective remediation strategies for crude oil- polluted environments.

Validating the utility of heavy water (Deuterium Oxide) as a potential Raman spectroscopic probe for identification of antibiotic resistance

The impact of microbial infections is increasing over time, and it is one of the major reasons for death in both developed and developing countries. colistin is considered as the antibiotic of last choice for infections brought by major multidrug-resistant (MDR), gram-negative bacteria such as Enterobacter species, Acinetobacter species, and Pseudomonas aeruginosa. Existing approaches to diagnose these resistant species are relatively slow and take up to 2 to 3 days. In this work, we propose a novel interdisciplinary method based on Raman spectroscopy and heavy water to identify colistin-resistant microbes. Our hypothesis is based on the fact that resistant bacteria will be metabolically active in the culture medium containing antibiotics and heavy water, and these bacteria will take up deuterium instead of hydrogen to newly synthesized lipids and proteins. This effect will generate a ‘C − D’ bond-specific Raman spectral marker. Successful identification of this band in the spectral profile can confirm the presence of colistin-resistant bacteria. We have validated the efficacy of this approach in identifying colistin-resistant bacteria spiked in artificial urine and have compared sensitivity at different bacterial concentrations. Overall findings suggest that heavy water can potentially serve as a suitable Raman probe for identifying metabolically active colistin-resistant bacteria via urine under clinically implementable time and can be used in clinical settings after validation.

Declining Trend in Antimicrobial Sensitivity in Respiratory Tract Bacterial Pathogens against Commonly Used Drugs at a Tertiary Care Hospital.

Antimicrobial resistance (AMR) is a major health issue. To determine trends in bacterial organisms in respiratory tract infections (RTIs) and their antibiotic sensitivity at a tertiary care center in India, we performed this study. Successive samples received from January 2017 to December 2021 from the respiratory tract (sputum, endotracheal secretion, and bronchoalveolar lavage) from intensive care units and medical inpatients were processed for bacterial growth. The identification of isolates and antibiotic sensitivity patterns was performed using an automated VITEK-2 system. Descriptive statistics are reported. We received 7,204 respiratory samples. Significant bacterial growth was in 3,000 (41.6%), and 2,992 (41.5%) were gram-negative. Klebsiella pneumoniae was the most prevalent, followed by Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, and Enterobacter aerogenes. Increasing secular trends were observed for Klebsiella and Pseudomonas and declining trends for Acinetobacter and Escherichia (p < 0.05). Antimicrobial sensitivity patterns showed that Klebsiella, Pseudomonas, Acinetobacter, E. coli, and Enterobacter had a high sensitivity with colistin and polymyxin (99-100%). Moderate sensitivity was observed with carbapenems (Acinetobacter: 47.5%, Enterobacter: 62.0%, Escherichia: 76.5%, Klebsiella: 72.3%, Pseudomonas: 66.7%) and tigecycline (Acinetobacter: 50.4%, Enterobacter: 68.0%, Escherichia: 81.1%, Klebsiella: 66.6%, Pseudomonas: 0%). Aminoglycosides had <50% sensitivity for various organisms, and <25% sensitivity was observed with third-generation cephalosporins and quinolones. Trend analysis showed persistent sensitivity of various pathogenic bacteria to colistin and polymyxin and declining pharmacological sensitivity in Acinetobacter (carbapenems and tigecycline), Escherichia (carbapenems, quinolones, and tigecycline), Klebsiella (carbapenems, quinolones, aminoglycosides, and tigecycline), and Pseudomonas (carbapenems and aminoglycosides) species (p < 0.05). Common respiratory tract gram-negative bacterial pathogens at a tertiary care hospital are K. pneumoniae, P. aeruginosa, A. baumannii, and E. coli. All these bacteria demonstrate high sensitivity only with colistin and polymyxin. Significant AMR is observed to carbapenems, tigecycline, aminoglycosides, and third-generation cephalosporins. Secular trends show declining antimicrobial sensitivity among various bacterial pathogens.