Reducing the toxicity caused by antibiotics on bacterial communities in the soil is one of the great challenges of this century. For this, the effectiveness of amending the soil with different bioadsorbents such as crushed mussel shell (CMS), pine bark (PB) and biomass ash (BA), as well as combinations of them (CMS + PB and PB + BA) was studied at different doses (0 g kg-1 to 48 g kg-1). Soil samples were spiked, separately, with increasing doses (0-2000 mg kg-1) of cefuroxime (CMX), amoxicillin (AMX), clarithromycin (CLA), azithromycin (AZI), ciprofloxacin (CIP) and trimethoprim (TMP). Their toxicity on bacterial growth was estimated using the tritium-labeled leucine (3H) incorporation method. Toxicity was observed to behave differently depending on the antibiotic family and bioadsorbent, although in different magnitude and at different doses. The toxicity of β-lactams (AMX and CXM) was reduced by up to 54% when the highest doses of bio-adsorbents were added due to the increase in pH (CMS and BA) and carbon (PB) contribution. Macrolides (CLA and AZI) showed slight toxicity in un-amended soil samples, which increased by up to 65% with the addition of the bio-adsorbents. The toxicity of CIP (a fluoroquinolone) increased with the dose of the bio-adsorbents, reaching up to 20% compared with the control. Finally, the toxicity of TMP (a diaminopyrimidine) slightly increased with the dose of bio-adsorbents. The by-products that increase soil pH are those that showed the highest increases of CLA, AZI, CIP and TMP toxicities. These results could help to prevent/reduce environmental pollution caused by different kinds of antibiotics, selecting the most appropriated bio-adsorbents and doses.

Transmission of bacteria between animals and humans in domestic households is increasingly recognized. We evaluated the presence of antimicrobial-resistant fecal bacteria in 8 dog-owner-dog pairs before and after the dog received amoxicillin-clavulanate. The study identified shared flora in the humans and dogs that were affected by antimicrobial administration.

Carbapenem-resistant Acinetobacter baumannii (CRAb) is an urgent public health threat, according to the CDC. This pathogen has few treatment options and causes severe nosocomial infections with > 50% fatality rate. Although previous studies have examined the proteome of CRAb, there have been no focused analyses of dynamic changes to β-lactamase expression that may occur due to drug exposure. Here, we present our initial proteomic study of variation in β-lactamase expression that occurs in CRAb with different β-lactam antibiotics. Briefly, drug resistance to Ab (ATCC 19606) was induced by the administration of various classes of β-lactam antibiotics, and the cell-free supernatant was isolated, concentrated, separated by SDS-PAGE, digested with trypsin, and identified by label-free LC-MS-based quantitative proteomics. Peptides were identified and evaluated using a 1789 sequence database of Ab β-lactamases from UniProt. Importantly, we observed that different antibiotics, even those of the same class (e.g. penicillin and amoxicillin), induce non-equivalent responses comprising various Class C and D serine-β-lactamases, resulting in unique resistomes. These results open the door to a new approach of analyzing and studying the problem of multi-drug resistance in bacteria that rely strongly on β-lactamase expression.

Bartonella sp. are the most common causes of culture-negative infective endocarditis (IE) cases in the United States. Although, infection-related glomerulonephritis can frequently mimic primary vasculitis due to pauci-immune pattern, majority of previously reported cases of Bartonella henselae-associated glomerulonephritis have immune-complex deposits on immunofluorescence. We present a rare case of B henselae IE-related pauci-immune necrotizing glomerulonephritis. Timely recognition of this atypical presentation led to appropriately directed medical therapy.

Streptococcus agalactiae infections may lead to clinical or subclinical mastitis in dairy animals when it invades the mammary gland. In this study, 51 S. agalactiae strains were isolated from 305 milk samples that were collected from goats with mastitis in 13 provinces of China. The antimicrobial resistance of S. agalactiae was determined by disk diffusion methods against 18 antibiotics from six classes. In addition, multilocus sequence typing (MLST), and the presence of resistance and virulence genes was determined by PCR analysis. Seven sequence types in five clonal complexes were identified according to MLST; CC103 and CC67 strains were predominant, with rates of 45.1% and 39.2%, respectively. All isolates (100%) were multiresistant to three or more antimicrobial agents. S. agalactiae isolates had a 100% resistance rate to penicillin, oxacillin, and amoxicillin, followed by doxycycline (82.4%), tetracycline (76.5%), and amikacin (74.5%). The lowest resistance was observed for ciprofloxacin (29.4%), which varied in five different regions. The detection rates of six classes of antimicrobial-related genes were calculated as follows: 33 (64.7%) for β-lactam-related resistance gene, 12 (23.5%) for tetracyclines, 11 (21.6%) for quinolone-related resistance genes, 10 (19.6%) for aminoglycosides, 7 (13.7%) for macrolides (ermA, ermB, and mefA), and 3 (5.9%) for lincosamide (lnu(B)). Regarding virulence genes, profile 1 (bca cfb-cspA-cylE-hylB-bibA-pavA-fbsA-fbsB) was the most prevalent, with a detection rate of 54.9%. This work provides a primary source related to the molecular epidemiology of S. agalactiae in dairy goat herds in China and will aid in the clinical treatment, prevention, and control of mastitis.

Approximately 36% of the United States (US) population is infected with Helicobacter pylori (HP), a known major risk factor for peptic ulcer disease and gastric cancer. HP eradication reduces the rate of complications; however, the benefits are undermined by rising rates of HP eradication treatment failure. This real-world observational cohort analysis aims to describe HP diagnostic and treatment patterns among insured patients in the US. Using diagnoses, lab results, and treatment patterns, we identified adults (18+) with new diagnoses of HP in the Veradigm Health Insights EHR Database linked to Komodo claims data (1/1/2016-12/31/2019). Patients were required to have ≥ 12 months of data pre-/post-index. We captured patient characteristics, HP-related diagnostic testing, and the use of US guideline-recommended HP eradication regimens. HP eradication rates following first-line eradication treatment were measured among patients with available lab results. Overall, 31.8% of the 60,593 included patients did not receive guideline-recommended treatment. Among the 68.2% (41,340) with first-line treatment, 80.2% received clarithromycin-based triple therapy, and 6.6% received bismuth quadruple therapy. Of the 4569 patients with a repeated course of eradication therapy, 53.4% received the same regimen as their first-line, the majority (90.7%) of whom received two rounds of clarithromycin-based triple therapy. Among the 2455 patients with results of HP non-serology testing following first-line treatment, the 180-day eradication rate was 80.2% overall, with differences based on treatments and demographics. This study highlights gaps between guideline-recommended HP management and real-world patterns, underscoring the need to improve HP testing, treatment, and follow-up practices.

A young adult man presented to an outlying emergency department with a sore throat, fever and chills. Upon failure of symptomatic management and a course of amoxicillin, he developed rectal pain and loose stools. Despite outpatient doxycycline treatment for presumed chlamydial proctitis, he developed worsening rectal pain and bloody stools. Results on abdominal and pelvic CT were consistent with proctitis. His symptoms worsened despite added metronidazole for bacterial proctitis. Workup revealed an elevated erythrocyte sedimentation rate, C reactive protein and calprotectin, suggestive of a diagnosis of inflammatory bowel disease (IBD). A colonoscopy revealed proximal tightness of the rectum, and pathology reported features suggestive of IBD. He was treated with prednisone and mesalamine. However, immunostaining positive for cytomegalovirus (CMV) confirmed a diagnosis of tissue-invasive CMV proctitis. This was further supported by serological testing for CMV consistent with a diagnosis of CMV proctitis preceded by a primary CMV infection of the pharynx.

A male in his 50s arrived by ambulance at a regional Australian hospital after being pinned by a buffalo against a fence by the chest and abdomen. Primary and secondary surveys identified an open fibula fracture and superficial abrasions. CT trauma series identified retropharyngeal free gas extending to the right carotid sheath. Flexible nasoendoscopy revealed a normal upper airway and no site of perforation. Oesophagoscopy and gastroscopy were completed to evaluate for a site of free gas leakage. A hypopharyngeal tear was identified 15 cm from the incisors at the cricopharyngeal sphincter. A gastrograffin swallow was completed which showed no leak. The decision was made to manage the patient conservatively with intravenous dexamethasone and intravenous ceftriaxone/metronidazole for antibiotic prophylaxis. The patient had his diet gradually upgraded and was discharged home 4 days later with oral amoxicillin and clavulanic acid.

Elucidating the interactions between plastic nanoparticles and small molecules is important to understanding these interactions as they occur in polluted waterways. For example, plastic that breaks down into micro- and nanoscale particles will interact with small molecule pollutants that are also present in contaminated waters. Other components of natural water, such as dissolved organic matter, will also influence these interactions. Here we use a collection of complementary NMR techniques to examine the binding between polystyrene nanoparticles and three common antibiotics, belonging to a class of molecules that are expected to be common in polluted water. Through examination of proton NMR signal intensity, relaxation times, saturation-transfer difference (STD) NMR, and competition STD-NMR, we find that the antibiotics have binding strengths in the order amoxicillin < metronidazole ≪ levofloxacin. Levofloxacin is able to compete for binding sites, preventing the other two antibiotics from binding. The presence of tannic acid disrupts the binding between levofloxacin and the polystyrene nanoparticles, but does not influence the binding between metronidazole and these nanoparticles.

Bacterial urinary tract infections (UTI) commonly occur in children; if left untreated, they may result in severe consequences such as uro-sepsis and renal damage. This study aimed to determine the bacterial profile, antimicrobial susceptibility patterns and associated factors among paediatric patients suspected of urinary tract infections in Arba Minch General Hospital (AMGH). An institution-based cross-sectional study was conducted from 01 October 2020 to 31 January 2021. A convenient sampling technique was used to recruit the participants; data were collected using a pre-tested questionnaire. To quantify the bacteria (as per the Kass count, >105CFU/ml), midstream urine samples were streaked onto bacteriological media. Isolates were identified by following standard procedures. The antibiotic susceptibility test was performed as per the Kirby-Bauer disc diffusion technique. Data were analyzed using SPSS software. Out of the 246 children included, 38 (15.4%) were found to be positive for significant bacteriuria. Isolates of Escherichia coli, 9/38 (23.7%), and Staphylococcus aureus, 9/38 (23.7%), were the most predominant. The majority of Gram-negative bacterial (GNB) isolates showed resistance towards amoxicillin-clavulanate (89.5%), ampicillin (84.6%), and ceftazidime (81%). Likewise, 76.9 and 76.5% of Gram-positive bacteria (GPB), respectively, had shown resistance towards co-trimoxazole and tetracycline. Multi-drug and extensively drug resistance were detected respectively in the case of 68.4 and 15.8% of the total isolates; ESBL production was found in 57.1% of GNB, whereas 55.6% of S. aureus were methicillin-resistant S. aureus (MRSA). The process of un-circumcision was significantly associated with UTI [(adjusted odds ratio= 3.578; 95% confidence interval: 1.263 - 10.13; p=0.016)].

Storing reclaimed water via managed aquifer recharge (MAR) is an effective strategy for alleviating groundwater overdraft and achieving water resource recycling simultaneously. However, β-lactam antibiotics in the reclaimed water can induce stress on aquifer system, reshape microbial community, and affect the emergence and prevalence of antibiotic resistance genes (ARGs). In this study, three sandy soil columns (H 1.5 m, ID 14 cm) were employed to simulate MAR, and synthetic reclaimed water containing either amoxicillin (AMO), ampicillin (AMP) or oxacillin (OXA) was continuously recharged for 120 d The temporal and spatial attenuation of β-lactams and nitrogen was studied, and microbial collaboration and the resistance mechanism were elaborated. Biodegradation is the main pathway for β-lactams elimination, AMO and AMP were eliminated when migrating 30 cm, while the attenuation of OXA experienced in the whole column with final removal efficiency of 82%. Moreover, refractory OXA induced more ARGs production, and approximately 10% and 13% higher than that of AMO and AMP columns. Efflux pump and antibiotics inactivation were the two major resistance mechanisms. NO3--N gradually decreased (by 26%, 38%, and 49% for AMO, AMP, and OXA, respectively) along the recharge direction. Microbial co-occurrence network revealed that nitrogen-cycling bacteria were the keystone species in aquifer community, and ammonation provided NH4+-N for the nitrification process of ammonia-oxidizing archaea (AOA), promoting the further denitrification for nitrogen removal in MAR process. Nitrogen-cycling bacteria were the key and active ARG hosts, which could keep nitrogen transformation activity under antibiotics stress. In sum, nitrogen-cycling bacteria exhibited intimate collaboration and elastic resistance in response to the malnutrition environment and β-lactams exposure during MAR.

The present study revealed the emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) and the associated driving factors in an urban river system surrounding Cuttack city, Odisha. The high contamination factor and contamination degree indicate poor water quality. The CRKP isolates showed 100% resistance against piperacillin, amoxicillin-clavulanic acid, piperacillin-tazobactam, ceftriaxone, ceftazidime, meropenem, and imipenem but less resistance to colistin (12.85%). Among the CRKP isolates, carbapenemase genes blaNDM, blaOXA-48-like, and blaKPC were detected in 94.28%, 35%, and 10% of isolates, respectively. The resistance genes (blaNDM, blaTEM, and blaCTX-M) were found to be significantly correlated with toxic metals (As, Cd, Co, Cu, Fe, Mn, Pb) (P < 0.05). Detection of virulence factors (yersiniabactin and aerobactin) and capsular serotypes (K1, K2, and K54 types) explain the pathogenicity of CRKP isolates. Enterobacterial repetitive intergenic consensus-PCR based molecular typing separated the CRKP strains into 13 clusters, of which VI and XI clusters showed similar resistance and virulence determinants, indicating the dissemination of clones from wastewater to the river system. Our results provide first-hand information on assessing risks to public health posed by the CRKP isolates and toxic metals in the Kathajodi River. Molecular surveillance of nearby hospitals for the prevalence of CRKP will help trace their transmission route.

The environmental accumulation and spread of antibiotic resistance pose a major threat to global health. Aerobic composting has become an important hotspot of combined pollution [e.g., antibiotic resistance genes (ARGs) and heavy metals (HMs)] in the process of centralized treatment and resource utilization of manure. However, the interaction mechanisms and environmental drivers of HMs resistome (MRGs), antibiotic resistance (genotype and phenotype), and microbiome during aerobic composting under the widely used amoxicillin (AMX) selection pressure are still poorly understood. Here, we investigated the dynamics of HMs bioavailability and their MRGs, AMX-resistant bacteria (ARB) and antibiotic resistome (ARGs and intI1), and bacterial community to decipher the impact mechanism of AMX by conducting aerobic composting experiments. We detected higher exchangeable HMs and MRGs in the AMX group than the control group, especially for the czrC gene, indicating that AMX exposure may inhibit HMs passivation and promote some MRGs. The presence of AMX significantly altered bacterial community composition and AMX-resistant and -sensitive bacterial structures, elevating antibiotic resistome and its potential transmission risks, in which the proportions of ARB and intI1 were greatly increased to 148- and 11.6-fold compared to the control group. Proteobacteria and Actinobacteria were significant biomarkers of AMX exposure and may be critical in promoting bacterial resistance development. S0134_terrestrial_group was significantly negatively correlated with blaTEM and czrC genes, which might play a role in the elimination of some ARGs and MRGs. Except for the basic physicochemical (MC, C/N, and pH) and nutritional indicators (NO3 --N, NH4 +-N), Bio-Cu may be an important environmental driver regulating bacterial resistance during composting. These findings suggested the importance of the interaction mechanism of combined pollution and its synergistic treatment during aerobic composting need to be emphasized.

Since 2016, following the Italian "National Plan to Contrast Antimicrobial Resistance", Campania Region has implemented an antimicrobial stewardship program, including the obligation to associate an appropriate International Classification of Diseases-9 code to each antibiotic prescription, the publication of schemes for empirical antibiotic therapy and educational interventions.

This study aimed to examine specific niches and usage for the aztreonam/amoxicillin/clavulanate combination and to use population pharmacokinetic simulations of clinical dosing regimens to predict the impact of this combination on restricting mutant selection. The in vitro susceptibility of 19 New-Delhi metallo-β-lactamase (NDM)-producing clinical isolates to amoxicillin/clavulanate and aztreonam alone and in co-administration was determined based on the minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC). The fractions of a 24-h duration that the free drug concentration was within the mutant selection window (fTMSW) and above the MPC (fT>MPC) in both plasma and epithelial lining fluid were determined from simulations of 10,000 subject profiles based on regimens by renal function categories. This combination reduced the MIC of aztreonam and amoxicillin/clavulanate to values below their clinical breakpoint in 7/9 K. pneumoniae and 8/9 E. coli, depending on the β-lactamase genes detected in the isolate. In the majority of the tested isolates, the combination resulted in fT>MPC > 90% and fTMSW < 10% for both aztreonam and amoxicillin/clavulanate. Clinical dosing regimens of aztreonam and amoxicillin/clavulanate were sufficient to provide mutant restriction coverage for MPC and MIC ≤ 4 mg/L. This combination has limited coverage against NDM- and extended-spectrum β-lactamase co-producing E. coli and K. pneumoniae and is not effective against isolates carrying plasmid-mediated AmpC and KPC-2. This study offers a potential scope and limitations as to where the aztreonam/amoxicillin/clavulanate combination may succeed or fail.

Prudent antibiotic use in pigs is critical to ensuring animal health and preventing the development of critical resistance. We evaluated the antimicrobial resistance (AMR) pattern in commensal and enterotoxigenic Escherichia&nbsp;coli (ETEC) isolates obtained in 2017-2021 from pigs suffering from enteric disorders. Overall, the selected 826 E. coli isolates showed the highest level of resistance to ampicillin (95.9%), tetracycline (89.7%), cefazolin (79.3%), and trimethoprim/sulfamethoxazole (74.8%). The resistance rates of the isolates to ampicillin increased (p < 0.05), reaching 99.2% of resistant strains in 2021. Regarding isolates harboring virulence genes, ETEC F18+ were significantly more resistant to florfenicol, gentamicin, kanamycin, and trimethoprim/sulfamethoxazole than ETEC F4+ strains. E. coli lacking virulence factor genes were more resistant to amoxicillin with clavulanic acid and cefazolin, but less resistant to gentamicin (p < 0.01) than isolates harboring virulence factors. Throughout the study period, a significant number of ETEC F18+ isolates developed resistance to florfenicol, gentamicin, and kanamycin. Finally, ETEC 18+ significantly (p < 0.05) increased resistance to all the tested antibiotics. In conclusion, AMR varied for E. coli over time and showed high levels for molecules widely administered in the swine industry, emphasizing the need for continuous surveillance. The observed differences in AMR between commensal and ETEC isolates may lead to the hypothesis that plasmids carrying virulence genes are also responsible for AMR in E. coli, suggesting more research on genetic variation between pathogenic and nonpathogenic E. coli.