Isolates Of Gram-negative Bacteria Research Articles

Preventing New Gram-negative Resistance Through Beta-lactam De-escalation in Hospitalized Patients With Sepsis: A Retrospective Cohort Study.

Whether antibiotic de-escalation reduces the risk of subsequent antibiotic resistance is uncertain. We sought to determine if beta-lactam (BL) antibiotic de-escalation is associated with decreased incidence of new Gram-negative resistance in hospitalized patients with sepsis. In a retrospective cohort study, patients with sepsis who were treated with at least 3 consecutive days of BL antibiotics, the first 2 days of which were with a broad-spectrum BL agent defined as a spectrum score (SS) of ≥7 were enrolled. Patients were grouped into three categories: (1) de-escalation of beta-lactam spectrum score (BLSS), (2) no change in BLSS, or (3) escalation of BLSS. The primary outcome was the isolation of a new drug-resistant Gram-negative bacteria from a clinical culture within 60 days of cohort entry. Fine-Gray proportional hazards regression modeling while accounting for in-hospital death as a competing risk was performed. Six hundred forty-four patients of 7742 (8.3%) patients developed new gram-negative resistance. The mean time to resistance was 23.7 days yielding an incidence rate of 1.85 (95% confidence interval [CI]: 1.71-2.00) per 1000 patient-days. The lowest incidence rate was observed in the de-escalated group 1.42 (95% CI: 1.16-1.68) per 1000 patient-days. Statistically significant reductions in the development of new gram-negative resistance were associated with BL de-escalation compared to no-change (hazards ratio (HR) 0.59 [95% CI: .48-.73]). De-escalation was associated with a decreased risk of new resistance development compared to no change. This represents the largest study to date showing the utility of de-escalation in the prevention of antimicrobial resistance.

In vitro study of the antibacterial effects of the Cydonia oblonga extract

Cydonia oblonga is effective against many infections and has medicinal properties that are useful in the treatment of many other diseases. The aim of this study was to elucidate the antimicrobial activity (in the form of anti-adherence and anti-biofilm formation) of the aqueous Cydonia oblonga extract. The biological activity of the extract was compared to that of imipenem. All bacterial isolates of Gram-positive and Gram-negative bacteria assessed were found to be susceptible to the Cydonia oblonga extract and the zone of inhibition ranged from 24 to 34 mm. Most bacterial isolates were resistant to the antibiotic, and some bacterial isolates were sensitive to imipenem. The adherence and biofilm formation inhibitory activities in the presence of the aqueous extract of Cydonia oblonga were found to be moderate or elevated in most of the Gram-negative bacteria assessed. According to our findings, the aqueous Cydonia oblonga extract displays great effectiveness (and promise) against many pathogenic bacterial isolates.

ENUMERATION AND DETERMINATION OF ANTIBIOGRAM OF BACTERIA ISOLATES FROM HAND-DUG WELL WATER IN BOSSO METROPOLIS, NIGERIA

Regular water supply surveillance is crucial in low-income nations like Nigeria, where households often rely on alternative sources, predisposing preventable water-borne diseases. Therefore, this study determined the occurrence and antibiogram of bacteria in hand-dug well water in Bosso metropolis, Nigeria. Exactly 10 well water samples were collected and processed for bacteria isolation and identification using standard microbiological techniques. The antibiotic sensitivity was determined via Kirby-Bauer disc diffusion techniques. The total viable bacteria count ranged from 0.45×103 cfu/mL to 2.15×104 cfu/mL, while the total coliform bacteria count ranged from 0.27×103 cfu/mL to 8.91×104 cfu/mL. Out of the 18 different bacteria isolated, Pseudomonas species had the highest occurrence (26.9%), and the least (3.9%) was observed for each of Shigella sp., Klebsiella sp., and Staphylococcus aureus. Also, 7 out 26 bacterial isolates isolated were multidrug-resistant. Escherichia coli, Shigella sp., Salmonella sp., Pseudomonas sp., and Klebsiella sp. were susceptible (100%) to ciprofloxacin and ofloxacin, though resistant (100%) to ampicillin and amoxycillin/clavulanate. All the Gram-negative bacteria isolates except Salmonella sp. were susceptible to gentamycin. Similarly, Pseudomonas sp., Proteus sp., and Salmonella sp. exhibited varied resistance to nitrofurantoin (71–100%), cefuroxime (50–100%), and ceftazidime (42.9–100%). Bacillus sp., Enterococcus sp., Staphylococcus sp., and Streptococcus sp. were resistant to cloxicillin and amoxycillin/clavulanate. In addition, Bacillus sp. (100%) and Enterococcus sp. (100%) were resistant to ciprofloxacin while remaining susceptible to ofloxacin and amoxycillin/clavulanate. Our findings highlight the urgent need for enhanced water quality and public health measures in the study areas...

Antimicrobial Activity and Phytochemical Composition of Allium sativum Bulb Extracts against Selected Gram-Negative Bacteria

As a result of increasing antibiotics resistance due to multidrug resistance leads to the use of the medicinal plants as alternative antimicrobial agents. The study aimed to investigate the antimicrobial and phytochemical properties of Allium sativum bulb extracts against some selected gram-negative bacteria isolates. Allium sativum oil was extracted using Soxhlet extraction procedures; Clinical bacterial isolates were collected from pathology department of General Hospital Potiskum in Yobe state. Isolates were identified using standard methods. Antibacterial activity of different concentrations (20, 40, 60, 80 and 100) % of oil extract of Allium sativum bulb were investigated against five clinical bacterial isolates including, Proteus vulgaris, Pseudomonas aeruginosa, Escherichia coli, Shigella boydii and Klebsiella oxytoca.. The oil extract of the bulbs showed antimicrobial activity against all five clinical isolates. MICs and MBCs were evaluated by broth dilution method. The minimum inhibitory concentration (MIC) values for all the three oil extracts ranged between 0.5 and 1.0%, while the minimum bacterial concentration (MBC) values ranged between 1.0 and 1.5%. Important bioactive constituents were present in the different oil extraction method; alkaloids (for ethanol extracts, 19.04±0.04, for hexane extracts, 20.04±0.14 and for chloroform extracts, 20.04±0.07) and 0.51±0.01were detected for sterols in all the three oil extraction methods while others such as flavonoids, saponins, tannins and phenols were not detected. The yield extracts of the oil extract of the bulbs, for hexane were 12.6%, chloroform, 15.2% and ethanol, 16.2%, indicating that ethanol was the better of the three solvents used. The potential applications of Allium sativum oil extracts as natural antimicrobial agents call for the importance of further investigation into their nutritional potential.

Assessment of bacterial profile, antimicrobial susceptibility status, and associated factors of isolates among hospitalized patients at Dessie Comprehensive Specialized Hospital, Northeast Ethiopia

BackgroundAntimicrobial resistant bacteria among hospitalized patients are becoming a major public health threat worldwide, mainly in developing countries. Infections by these multidrug resistant pathogens cause high rate of mortality, prolong hospital stays, and affect individual and country economies in greater amounts. Thus, this study aimed to assess the bacterial profile, antimicrobial susceptibility status, and associated factors of isolates from hospitalized patients at the Dessie Comprehensive Specialized Hospital.MethodologyThis hospital-based cross-sectional study was conducted between February and April 2021. Consecutive sampling was used to select the study participants. All bacterial isolates were identified using standard bacteriological techniques. Antibiotic susceptibility testing was performed using disk diffusion technique. The data was analyzed using SPSS version 25. Descriptive statistics and logistic regression were used. A P-value of less than 0.05 was considered statistically significant.ResultsOf 384 clinical samples (blood, urine, stool, wound, vaginal discharge, and ear discharge) processed 180 (46.9%) were culture positive. Overall, Escherichia coli was the predominant isolate (41; 22.8%), followed by Staphylococcus aureus (36; 20%). Most of the isolates were from blood (70; 38.9%). The level of overall drug resistance of the gram-negative bacteria isolates for ampicillin, tetracycline, and cotrimoxazole was (104; 88.1%), (79; 75.9%), and (78; 75.0%), respectively. The overall multidrug rate of isolates was 143 (79.4%). Variables such as history of invasive procedures, chronic underlying diseases, history of hospitalization, and habit of eating raw animal products were statistically significant for the acquisition of bacterial infection.Conclusions and recommendationE. Coli and S. aureus were the most common isolates. Most of the isolates were resistant to commonly prescribed antibiotics. And also, consumption of raw animal products, chronic underlying disease, previous hospitalization, history of invasive procedures, and educational status were associated with the acquisition of bacterial infections. Therefore, routine antimicrobial susceptibility testing, proper patient management, wise use of antibiotics in clinical settings and health education are recommended.

Brazilian Study on the Prevalence of Carbapenemase Producing Organisms and Their Relation with Patients’ Death Rate

Aims: Determine the clinical characteristics of patients and the microbiological characteristics of the isolated Gram-negative microorganisms; Analyze the relationship between hospitalization sectors and the occurrence of bacteria resistant to carbapenems; Determine the prevalence of Gram-negative in clinical sectors of a University Hospital from Fortaleza, Brazil; Relate the prevalence to resistent Gram-negative bacteria with patients’ death rate.
 Study Design: This is a descriptive, retrospective and cross-sectional study, carried out between January and December 2022 at a university hospital in Fortaleza, Brazil.
 Place and Duration of Study: Microbiology Sector of the Central Laboratory of the Walter Cantídio University Hospital between January 2022 and December 2022.
 Methodology: All reports that showed a positive culture for Gram-negative bacilli and that carried out antibiotic sensitivity testing were included in the study. Their identification (ID) and the Antibiotic Sensitivity Test (TSA) were carried out using the automated system VITEK® 2 (BioMérieux®, Marcyl’Etoile, France), which uses the OBSERVA system for data archiving. The data was collected on a specific form and collected through patient reports issued by the hospital system. The forms were reviewed by a microbiologist pharmacist from the microbiology service. The data were analyzed and audited in the Excel® program for statistical validation using the SPSS Statistics® program, version 17.0.
 Results: 398 samples positive for Gram-negative microorganisms were collected. These samples referred to 236 patients admitted to different sectors of the hospital. It was seen that the Surgical Center concentrated a greater number of patients, representing 66 individuals (28%). The most frequently isolated species (n=217) were Klebsiella pneumoniae (n= 70; 23%) and Pseudomonas aeruginosa (n= 70; 23%), followed by Escherichia coli (n= 43; 14%) and Acinetobacter baumannii (n = 34; 11%), respectively. It was observed that 29.9% of GNB were isolated from blood samples, this being the most prevalent biological site. Bloodstream infection (BSI) was identified as the biological site with the highest number of cases, recording 65 (29.9%) positive isolates in the blood. It was found that 131 isolates of Gram-negative bacteria presented resistance mechanisms, with resistance to carbapenems being the most prevalent, corresponding to 42.75% of cases originating from enterobacteria. It was found that admission to the adult ICU increases the chances of death by 6.017 (OR) times in patients who isolated carbapenem-resistant GNBs (p <0.001).
 Conclusion: The study analyzed the microbial profile of patients at a university hospital, identifying a significant association between death and microbial resistance, especially with Klebsiella pneumoniae. Bloodstream infections were frequent, being the site with the highest number of cases. The predominant resistance mechanism was Carbapenem-Resistant Enterobacteriaceae (CRE). The results highlight the need for continuous monitoring and control of antimicrobial resistance to guide epidemiological strategies.

DETERMINING THE OCCURRENCE OF SOME VIRULENCE GENES IN PROTEUS SPECIES ISOLATES

Forty isolates of Gram-negative rod-shaped bacteria termed as Proteus, widely known for their swarming motility and urease activity, which cause complicated urinary tract infections (UTIs), were isolated and identified. Two hundred and ten urine specimens collected from the patients suffering from UTIs, who were hospitalized in Babylon hospitals, were used for the isolation of Proteus species isolates. The morphological features (for cells and colonies), biochemical tests, VITEK 2 compact and polymerase chain reaction (PCR) for Proteus-specific genes were used for the identification of these isolates. The assessment of the antimicrobial profiles that represent the prevalence and the level of pathogenicity of the isolates was also carried out. Furthermore, the whole genomic DNA of the isolates was extracted to determine the sites of blaTEM, blaCTX-M, and blaSHV genes on the genome of the isolates. The results revealed that thirty isolates were P. mirabilis and ten isolates were P. vulgaris. These isolates were given names as PM1 to PM30 for P. mirabilis and PV31 to PV40 for P. vulgaris. The most effective antibiotics against the isolates were erythromycin (97.5%), followed by tobramycin (85%), ampicillin (82.5%), chloramphenicol (60%), piperacillin (55%) and 52.5% for each sulfamethoxazole and azithromycin. The meropenem and imipenem showed less resistance (35%) followed by ciprofloxacin (30%) and gentamicin (15%). The PCR assay exhibited that these isolates carried blaTEM gene at the rate of 38/40 (95%), blaSHV gene at the rate of 33/40 (82.5%) and blaCTX-M gene at the rate of 37/40 (92.5%). Therefore, reducing the frequency and severity of infections, however, more research is needed to understand how the rates of pathogenicity of Proteus species isolates can be controlled.

Nitric Oxide and Hypochlorite Assessment and Screening of some β-Lactamase Encoding Genes among Gram Negative Bacteria in Patients with Acute Leukemia

Objective: The serologic levels of both nitric oxide (NO) and hypochlorite (ClO-) were assessed in this study for Iraqi acute leukemic patients infected with Gram negative bacteria (GNB). Alongside, the phylogenetic analysis for both blaSHV and blaTEM genes of GNB was performed. Methods: The clinical samples were recovered from acute leukemic patients at hematology center in Baghdad from January 2021 to December 2021. The identification of bacterial isolates and susceptibility test were performed using Vitek 2 Compact System. Serum levels of NO and ClO- were assayed by Enzyme Linked Immunosorbent assay and colorimetric method, respectively. Gene screening was done utilizing polymerase chain reaction. DNA sequencing, GenBank accession numbers submission, and phylogenetic analysis were also conducted. Results: From 260 patients with acute leukemia, 485 clinical samples were collected from different sites. Of this total, 70 (15%) isolates of GNB were obtained, distributing as Klebsiella pneumoniae 23 (33%), Escherichia coli 21 (30%), Pseudomonas aeruginosa 18 (26%), and Acinetobacter baumannii 8 (11%). These isolates were mainly collected from urine 39 (55.71%), followed by blood 23 (32.85%), and the least from swabs 8 (11.42%). The infections of GNB were higher among acute myeloblastic leukemia (AML) patients 40 (57.14%) than these with acute lymphoblastic leukemia (ALL) 30 (42.85%). The levels of NO were higher among groups of patients than control groups. Additionally, ClO-levels were observed to be slightly increased in patients above these of controls. Most isolates of K. pneumoniae and E. coli showed high resistance rates for penicillins (ampicillin and ticarcillin), cephalosporins (ceftazidime, cefotaxime, ceftriaxone, and cefepime), followed by gentamicin and ciprofloxacin. Cefoxitin, aztreonam, imipenem and meropenem were nearly more effective against GNB isolates. On the other hand, about half isolates P. aeruginosa and all A. baumannii were resistant to the tested antibiotics. Extended Spectrum β- Lactamases (ESBLs) were released in 49 (70%) of the tested isolates of GNB. The multidrug resistant (MDR) pattern was noticed among 58 (82.85%) of GNB. Interestingly, ESBLs producing MDR isolates were determined in 34 (58.62%) of the studied GNB. Genotypic screening revealed that blaSHV and blaTEM genes were characterized in 20 (28.57%) and 32 (45.71%) of GNB isolates, respectively, while all GNB were negative for blaCTX-M. DNA sequencing of blaSHV amplicons revealed the occurrence of one point mutation (111T>A) in six isolates of K. pneumoniae with a missense effect (p.31Q>L) on the encoded protein. Forty-five GenBank accession numbers were recorded in NCBI to represent the studied variants of ESBLs. Phylogenetic analysis of both blaSHV and blaTEM displayed the possible epidemiologic routes of the tested GNB by detecting the origin host, source of collection, and geographic spread as compared with the reference sequences. Conclusion: high serum levels of both NO and ClO- indicated the potential role of these microbicidal agents to predict the serious infections of GNB in acute leukemia population. Phylogenetic analysis represented an important tool, possibly aiding in early control and prevention of pathogenic GNB.

Antimicrobial susceptibility of Gram-Negative Infections in King Faisal Medical Complex at Taif, Saudi Arabia

Objectives: Describe susceptibility patterns to several antimicrobials in Gram-negative pathogens isolated from patients in King FaisalMedical Complex (KFMC) at Taif, Saudi Arabia over a 6-month period. Methods: The study included a cumulative antibiogram of Gram-negative bacteria (GNB). Interpretation of the antimicrobial susceptibilitytests was based on the Clinical and Laboratory Standards Institute (CLSI) guidelines and the Phoenix system. Results: Overall, 763 clinical infections by GNB isolates of the specimens collected during six months were culture-positive. Amongthe array of GNB, Escherichia coli numbered 290 (38.0%) was the most frequently identified, then Klebsiella pneumoniae 276 (36.2%),Pseudomonas aeruginosa 77 (10.1%), Acinetobacter baumannii 48 (6.3%), Proteus spp. 31 (4.1%), Citrobacter koseri 11 (1.4%), Serratiaspp. 8 (1.0 %), Enterobacter aerogenes 7 (0.9%), Klebsiella Oxytoca 4 (0.5%), Providencia rettgeri 3 (0.4 %), Klebsiella ozaenae 3 (0.4%),Morganella morganii 2 (0.3%), Stenotrophomonas maltophilia 2 (0.3 %), and Pseudomonas puda 1 (0.1%). Fifty-one isolates were resistantto all tested antibiotics, but 97 (12.7 %) were susceptible to all the tested antibiotics. The majority (87.3%) of isolates were resistant toone or more antimicrobials tested. In general, 83% of the bacterial species were MDR. The carbapenem sensitivity was 68.7% for allGNB isolates, 47.3% and 52.3% of K. pneumoniae, 20.8% and 25% of Acinetobacter, and 64.1% and 75.6% of P. aeruginosa to imipenemand meropenem, respectively. The carbapenem sensitivity for E. coli was extremely high showing 100% and 99.9% for imipenem andmeropenem, respectively. Antibiotic sensitivity of the most isolated GNB pathogens was highly variable showing that tigecycline is themost effective antibiotic with 82.4% sensitivity while was non-effective for Acinetobacter. The colistin sensitivity was 88.3% for E. coli,69.2% for P. aeruginosa, 45.5% for K. pneumoniae and less effective against A. baumannii. Conclusion: Antibiotic resistance among K. pneumoniae, A. baumannii and P. aeruginosa was high for many used antibiotics, thus continued surveillance is needed.

717. Antimicrobial Resistance of Gram-Negative Bacteria in Respiratory Isolates from an Intensive Care Unit in Guatemala

Abstract Background Antimicrobial resistance (AMR) among Gram-negative bacteria (GNB) is a growing concern in public health, particularly in ICU settings. Over the past few decades, there has been a significant increase in ESBL and carbapenem resistance in Latin America, which has resulted in higher mortality rates and increased healthcare costs. One way to understand local bacterial resistance profiles is to examine respiratory isolates, which can serve as a proxy for resistance observed in the clinical setting. It is critical for clinicians to be aware of these profiles in order to make informed decisions about treatment options. Methods A retrospective study was conducted on all respiratory isolates from the ICU of a third-level national hospital over a 6-month period. All respiratory isolates were analyzed for to identify microorganisms and their AMR to selected antibiotics, including Ceftriaxone (CRO), Ceftazidime (CAZ), Cefepime (CEF) and carbapenems. Results A total of 500 isolates were obtained during the study period, resulting in the isolation of 988 microorganisms. GNB represented 92.3% (n=912) of these isolates. Pseudomonas spp was the most common GNB identified (28.07%), followed by Acinetobacter (26.97%) and Klebsiella spp (20.94%). Stenotrophomona isolates were excluded from the analysis as resistance profiling for this organism is not routinely performed in the institution, leaving a total of 868 isolates for AMR analysis. A total of 527 GNB isolates (60.78%) were identified as resistant to both 3rd generation cephalosporines and CEF. Strains with this resistance pattern were considered highly suggestive of ESBL production. Moreover, 66.78% (n=579) of GNB’s analyzed evidenced resistance to carbapenems, with 13.61% (n=118) of strains having been identified as carbapenemase-producing bacteria. Some GNB exhibited alarming levels of resistance as evidenced in table 1.Table 1.Resistance of selected GNBPercentage of bacterial strains from respiratory isolates resistant to selected antibiotics. Conclusion The high level or resistance observed in GNB from respiratory isolates in this study is concordant with other data from Latin America. While the prevalence of GNB in respiratory isolates does not necessarily correlates with clinical infection rates, the high level of resistance found may be an indicator of the AMR epidemiology of infections in this ICU. Disclosures All Authors: No reported disclosures

Prevalence of Antimicrobial Resistance in Gram-Negative Bacteria Bloodstream Infections in Peru and Associated Outcomes: VIRAPERU Study.

Surveillance of antimicrobial resistance among gram-negative bacteria (GNB) is of critical importance, but data for Peru are not available. To fill this gap, a non-interventional hospital-based surveillance study was conducted in 15 hospitals across Peru from July 2017 to October 2019. Consecutive unique blood culture isolates of key GNB (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter spp.) recovered from hospitalized patients were collected for centralized antimicrobial susceptibility testing, along with linked epidemiological and clinical data. A total of 449 isolates were included in the analysis. Resistance to third-generation cephalosporins (3GCs) was present in 266 (59.2%) GNB isolates. Among E. coli (n = 199), 68.3% showed 3GC resistance (i.e., above the median ratio for low- and middle-income countries in 2020 for this sustainable development goal indicator). Carbapenem resistance was present in 74 (16.5%) GNB isolates, with wide variation among species (0% in E. coli, 11.0% in K. pneumoniae, 37.0% in P. aeruginosa, and 60.8% in Acinetobacter spp. isolates). Co-resistance to carbapenems and colistin was found in seven (1.6%) GNB isolates. Empiric treatment covered the causative GNB in 63.3% of 215 cases. The in-hospital case fatality ratio was 33.3% (92/276). Pseudomonas aeruginosa species and carbapenem resistance were associated with higher risk of in-hospital death. In conclusion, an important proportion of bloodstream infections in Peru are caused by highly resistant GNB and are associated with high in-hospital mortality.

Retracted: In Vitro Activity of Various Sulbactam Compounds and Piperacillin/Tazobactam against Clinical Isolates of Different Gram-Negative Bacteria.

[This retracts the article DOI: 10.1155/2021/1175379.].

Antimicrobial Activity of Basil (Ocimum basilicum L.) Against Gram-Negative Bacteria Involved in Pneumonia Infection

Infectious diseases are still a global problem, for example, acute respiratory infections (SARI). Resistance in pneumonia involving Gram-negative bacterial infection reduces the effectiveness of antibiotic use and increases the length of hospital stay. This study examines the potential of antimicrobial compounds from basil plants against isolates of Gram-negative bacteria involved in pneumonia infection. This research is an experimental study through several stages: basil extraction, initial screening of bioactive compounds, isolation and identification of bacteria from sputum, and testing for antimicrobial activity of basil extracts. Sputum samples were collected from 43 pneumonia patients (male and female) involving Klebsiella pneumoniae, Acinetobacter baumannii, Enterobacter aerogenes, Pseudomonas aeruginosa, Serratia marcescens, Proteus mirabilis, and Escherichia coli. The inhibitory activity against pathogenic bacteria was directly proportional to the basil extract concentration. Initial screening for phytochemical compounds showed that the extracts of basil leaves and stems contained active compounds of tannins and flavonoids. The 25% concentration of basil extract was the minimum inhibitory concentration (MIC) against the test bacteria. The 100% basil extract concentration produced the largest inhibition zone i.e., 10.93 mm. The overall findings of this study provide baseline information for the possible use of the Ocimum basilicum extract in the treatment of pneumonia involving Gram-negative bacteria.

Surveillance of bacterial resistance in children aged 0-14 years from 2018 to 2022

Objective: To understand the distribution and antimicrobial resistance of common bacteria from children aged 0-14 years from China Antimicrobial Resistance Surveillance System. Methods: Bacterial resistance data of 2 575 040 strains from children aged 0-14 years were extracted from the national bacterial resistance surveillance reports from October 2018 to September 2022 and resistance changes were further analyzed by comparing with all data in each year. Results: The total number of bacteria isolated from children in 2018-2022 ranged from 415 306-588 016 strains, accounted for 15.9% (514 193/3 234 372), 16.2% (572 107/3 528 471), 12.8% (415 306/3 249 123), 13.0% (485 418/3 743 027), and 12.2% (588 016/4 828 509), respectively. The proportions of gram-positive bacteria among children were 45.4% (233 456/514 193), 44.5% (254 869/572 107), 44.7% (185 756/415 306), 42.6% (206 903/485 418), and 41.7% (245 044/588 016), respectively. The top five isolates of gram-positive bacteria were Staphylococcus aureus (36.0%-38.8%), Streptococcus pneumoniae (27.1%-31.7%), Staphylococcus epidermidis (7.3%-9.3%), Enterococcus faecium (4.0%-4.8%), and Enterococcus faecium (2.5%-3.6%), and the top five isolates of gram-negative bacteria were Escherichia coli (21.8%-26.2%), Haemophilus influenzae (14.4%-26.4%), Klebsiella pneumoniae (10.1%-14.7%), Moraxella catarrhalis (7.3%-11.9%), and Pseudomonas aeruginosa (5.5%-6.8%). The bacteria from children aged 0-14 years commonly isolated from sputum samples (48.8%-57.0%). The prevalence of methicillin-resistant S. aureus was 28.7%-30.1%. The detection rates of vancomycin-resistant E. faecalis or E. faecium were 0.1%-0.3%. The proportions of non-cerebrospinal fluid-derived penicillin-resistant S. pneumoniae were 0.7%-1.6%. The prevalence of cefotaxime and (or) ceftriaxone-resistant E. coli and K. pneumoniae decreased were 43.7%-50.0% and 31.8%-42.7%, respectively. The resistant rates of E. coli to imipenem and meropenem were 1.2%-1.9% and 1.2%-2.0%, respectively, and the resistant rates of K. pneumoniae to imipenem and meropenem were 7.3%-10.1% and 8.2%-12.2%, respectively. About 6.6%-10.2% and 5.3%-9.6% of the P. aeruginosa isolates showed resistant to imipenem and meropenem, respectively, while 17.2%-24.0% and 19.0%-29.4% of the Acinetobacter baumannii isolates were resistant to imipenem and meropenem, respectively. Conclusions: There is no significant change in the composition of common clinical pathogens in children aged 0-14 years from 2018 to 2022. The prevalence of some resistant bacteria such as methicillin-resistant S. aureus and carbapenem-resistant Enterobacterales is decreasing. However, it is necessary to pay attention to antimicrobial resistance of bacteria from children and long-term monitoring of the prevalence of resistant bacteria should be conducted.

Potential sources of water contamination in Sulaymaniyah city hospitals: isolation and identification of non-fermentative gram-negative bacteria

Potential sources of water contamination in Sulaymaniyah city hospitals: isolation and identification of non-fermentative gram-negative bacteria

Gram-negative bacteria of critical priority in ICU patients from a tertiary care hospital

Intensive care units (ICU) are the epicenter of antimicrobial resistance (AMR), and patients' infections are mainly caused by Gram-negative bacteria (GNB). To describe the frequency and trends in AMR of GNB deriving from the clinical samples of ICU patients at a tertiary care hospital in Mérida, Yucatán. Study which included the review of laboratory reports of all bacteriological samples collected from patients admitted to neonatal, pediatric and adult ICU from January 1 2019 to December 31 2021. 433 GNB isolates were recovered, with Klebsiella pneumoniae being the most predominant isolate (n = 117; 27.02%). The majority of GNB were recovered from bronchial secretions (n = 163). Overall, GNB showed high resistance rates to ampicillin (89.48%), ampicillin/sulbactam (66.85%), cephalosporins (58.52-93.81%), tobramycin (58.06%), and tetracycline (61.73%). Among GNB, 73.90% and 68.53% exhibited multidrug-resistant, and highly resistant microorganisms' profiles, respectively, and 47.54% of Acinetobacter baumannii exhibited an extensively drug-resistant profile. A total of 80.33% of A. baumannii was carbapenem-resistant, and 83.76% of K. pneumoniae strains were ESBL-producing. Our data could be helpful to improve the empirical therapy and the infection-control program.

Identification of TMexCD-TOprJ-producing carbapenem-resistant Gram-negative bacteria from hospital sewage.

Carbapenems and tigecycline are crucial antimicrobials for the treatment of gram-negative bacteria infections. Recently, a novel resistance-nodulation-division (RND) efflux pump gene cluster, tmexCD-toprJ, which confers resistance to tigecycline, has been discovered in animals and clinical isolates. It was reported that hospital sewage could act as a reservoir for gram-negative bacteria with high antimicrobial resistance genes. In this study, we analyzed 84 isolates of carbapenem-resistant gram-negative bacteria (CR-GNB) from hospital sewage, and identified five isolates of TMexCD-ToprJ-producing CR-GNB, including one Raoultella ornithinolytica isolate and four Pseudomonas spp. isolates. All these five isolates carried at least one carbapenem resistance gene and were resistant to multiple antibiotics. Multiple tmexCD-toprJ clusters were detected, including tmexC2D2-toprJ2, tmexC3D3-toprJ3, tmexC3.2D3.3-toprJ1b and tmexC3.2D3-toprJ1b. Among these clusters, the genetic construct of tmexC3.2D3-toprJ1b showed 2-fold higher minimum inhibitory concentration (MIC) of tigecycline than other three variants. In addition, it was found that the tmexCD-toprJ gene cluster was originated from Pseudomonas spp. and mainly located on Tn6855 variants inserted in the same umuC-like genes on chromosomes and plasmids. This unit co-localized with blaIMP or blaVIM on IncHI5-, IncpJBCL41- and IncpSTY-type plasmids in the five isolates of TMCR-GNB. The IncHI5- and IncpSTY-type plasmids had the ability to conjugal transfer to E. coli J53 and P. aeruginosa PAO1, highlighting the potential risk of transfer of tmexCD-toprJ from Pseudomonas spp. to Enterobacterales. Importantly, genomic analysis showed that similar tmexCD-toprJ-harboring IncHI5 plasmids were also detected in human samples, suggesting transmission between environmental and human sectors. The emergence of TMCR-GNB from hospital sewage underscores the need for ongoing surveillance of antimicrobial resistance genes, particularly the novel resistance genes such as the tmexCD-toprJ gene clusters in the wastewater environment.

Antimicrobial Susceptibility Among Gram-Negative Isolates in Pediatric Patients in Latin America, Africa-Middle East, and Asia From 2016-2020 Compared to 2011-2015: Results From the ATLAS Surveillance Study.

Antimicrobial resistance (AMR) data in the pediatric population are limited, particularly in developing countries. This study assessed the AMR profile and key resistance phenotypes and genotypes for Gram-negative bacteria (GNB) isolates collected as part of the Antimicrobial Testing Leadership and Surveillance program from pediatric patients in Latin America, Africa-Middle East, and Asia in 2016-2020 versus 2011-2015. Minimum inhibitory concentrations by broth microdilution methodology were interpreted per the Clinical and Laboratory Standards Institute. European Committee on Antimicrobial Susceptibility Testing breakpoints were used for interpreting colistin activity. β-lactamase genes were screened by polymerase chain reaction and sequencing. For Acinetobacter baumannii, low susceptibility (<60.0%) was observed for all antimicrobials, except colistin (≥92.9%), across regions and year periods. Ceftazidime-avibactam, amikacin, colistin, and meropenem were mostly active (78.6%-100.0%) against Enterobacter cloacae, Escherichia coli, and Klebsiella pneumoniae. For Pseudomonas aeruginosa, susceptibility to ceftazidime-avibactam, amikacin, and colistin was ≥85.9%. Among resistance phenotypes, carbapenem-resistant (CR, ≥44.8%) and difficult-to-treat resistant (DTR, ≥37.1%) rates were the highest in A. baumannii. A consistent increase in CR and DTR K. pneumoniae was noted across regions over time. Extended-spectrum β-lactamases (ESBL)-producing K. pneumoniae (32.6%-55.6%) were more frequent than ESBL-producing E. coli (25.3%-37.1%). CTX-M was the dominant ESBL among Enterobacterales. NDM-positive Enterobacterales species and VIM-positive P. aeruginosa were identified across regions. This study identified high susceptibility to few agents for key GNB in pediatric patients. Continued surveillance of resistance phenotypes and genotypes at regional levels may help to guide appropriate treatment decisions.

Synergistic action of indole-3-carbinol with membrane-active agents against multidrug-resistant Gram-negative bacteria.

The purpose of this study was to evaluate the antimicrobial activity of indole-3-carbinol (I3C) with membrane-active agents, namely carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and ethylenediaminetetraacetic acid (EDTA) against multidrug-resistant (MDR) Gram-negative bacteria and bacterial persisters. The determination of minimal inhibitory concentration (MIC) showed that I3C was effective against Acinetobacter baumannii (3.13‒6.25×10-3mol l-1), Klebsiella pneumoniae (8×10-3mol l-1), Pseudomonas aeruginosa (6.25‒12.5×10-3mol l-1), and Escherichia coli (6.25‒12.5×10-3mol l-1). Our study demonstrated that EDTA synergistically enhanced the bactericidal activity of I3C against most MDR Gram-negative bacteria isolates and contributed to an 8- to 64-fold MIC reduction compared with that of I3C alone, yet CCCP only displayed synergy with I3C against P. aeruginosa and A. baumannii. The EDTA-I3C combination also significantly reduced the viable number of testing bacteria (P=7.2E-05), effectively reduced bacterial persisters, and repressed bacterial growth compared with that the use of I3C alone. Our data demonstrate that use of EDTA as adjuvant molecules can effectively improve the antibacterial activity of I3C and may help to reduce the development of antimicrobial resistance.

Functional immune boosters; the herb or its dead microbiome? Antigenic TLR4 agonist MAMPs found in 65 medicinal roots and algae's.

Humans have been consuming medicinal plants (as herbs/ spices) to combat illness for centuries while ascribing beneficial effects predominantly to the plant/phytochemical constituents, without recognizing the power of obligatory resident microorganism' communities (MOCs) (live/dead bacteria, fungus, yeast, molds etc.) which remain after industrial microbial reduction methods. Very little is known about the taxonomic identity of residual antigenic microbial associated molecular patterns (MAMPs) debris in our botanical over the counter (OTC) products, which if present would be recognized as foreign (non-self) antigenic matter by host pattern recognition receptors (PRRs) provoking a host immune response; this the basis of vaccine adjuvants. As of today, only few research groups have removed the herbal MAMP biomass from herbs, all suggesting that immune activation may not be from the plant but rather its microbial biomass; a hypothesis we corroborate. The purpose of this work was to conduct a high through put screening (HTPS) of over 2500 natural plants, OTC botanical supplements and phytochemicals to elucidate those with pro-inflammatory; toll like receptor 4 (TLR4) activating properties in macrophages. The HTPS was conducted on RAW 264.7 cells vs. lipopolysaccharide (LPS) E. coli 0111:B4, testing iNOS / nitric oxide production as a perimeter endpoint. The data show not a single drug/chemical/ phytochemical and approximately 98 % of botanicals to be immune idle (not effective) with only 65 pro-inflammatory (hits) in a potency range of LPS. Method validation studies eliminated the possibility of false artifact or contamination, and results were cross verified through multiple vendors/ manufacturers/lot numbers by botanical species. Lead botanicals were evaluated for plant concentration of LPS, 1,3:1,6-β-glucan, 1,3:1,4-β-D-glucan and α-glucans; where the former paralleled strength in vitro. LPS was then removed from plants using high-capacity endotoxin poly lysine columns, where bioactivity of LPS null "plant" extracts were lost. The stability of E.Coli 0111:B4 in an acid stomach mimetic model was confirmed. Last, we conducted a reverse culture on aerobic plate counts (APCs) from select hits, with subsequent isolation of gram-negative bacteria (MacConkey agar). Cultures were 1) heat destroyed (retested/ confirming bioactivity) and 2) subject to taxonomical identification by genetic sequencing 18S, ITS1, 5.8 s, ITS2 28S, and 16S. The data show significant gram negative MAMP biomass dominance in A) roots (e.g. echinacea, yucca, burdock, stinging nettle, sarsaparilla, hydrangea, poke, madder, calamus, rhaponticum, pleurisy, aconite etc.) and B) oceanic plants / algae's (e.g. bladderwrack, chlorella, spirulina, kelp, and "OTC Seamoss-blends" (irish moss, bladderwrack, burdock root etc), as well as other random herbs (eg. corn silk, cleavers, watercress, cardamom seed, tribulus, duckweed, puffball, hordeum and pollen). The results show a dominance of gram negative microbes (e.g. Klebsilla aerogenes, Pantoae agglomerans, Cronobacter sakazakii), fungus (Glomeracaea, Ascomycota, Irpex lacteus, Aureobasidium pullulans, Fibroporia albicans, Chlorociboria clavula, Aspergillus_sp JUC-2), with black walnut hull, echinacea and burdock root also containing gram positive microbial strains (Fontibacillus, Paenibacillus, Enterococcus gallinarum, Bromate-reducing bacterium B6 and various strains of Clostridium). This work brings attention to the existence of a functional immune bioactive herbal microbiome, independent from the plant. There is need to further this avenue of research, which should be carried out with consideration as to both positive or negative consequences arising from daily consumption of botanicals highly laden with bioactive MAMPS.