Effect of colloid-size copper-based pesticides and wood-preservatives against microbial activities of Gram-positive Bacillus species using five-day biochemical oxygen demand test.

Copper-based pesticides and wood preservatives could end up in the environment during production, use, and end-of-life via different pathways that could cause unintended ecological and adverse health effects. This paper provides the effect of colloid-size Cu-based pesticides (CuPRO and Kocide), micronized Cu azole (MCA-1 and MCA-2) and alkaline Cu quaternary (ACQ) treated woods, Cu2+, Cu2+ spiked untreated wood (UTW), and CuCO3 solutions against Gram-positive Bacillus species using five-day biochemical oxygen demand (BOD5) standard test. The total Cu leached from MCA-1, MCA-2, and ACQ in Milli-Q water after 5 days were ~0.1, ~0.11, and ~0.64 g/kg of wood, respectively. However, the form of Cu leached from MCA woods was mostly ionic (> 90%). The total organic carbon (TOC) content of any tested wood (UTW/MCA-1/MCA-2/ACQ) was ~99% of its corresponding total carbon (TC) content, whereas the TOC of any tested wood sawdust exceeded that of its corresponding piece/block by > 300%. The dissolved oxygen (DO) consumption value in the presence of Cu2+, CuCO3, CuPRO, and Kocide solutions was significantly influenced by Cu particles/ions. However, the DO consumption value in the presence of UTW/MCA-1/MCA-2/ACQ woods was significantly influenced by organics leached from woods. On the other hand, the DO consumption of MCA sawdust was greater than (300%) that of MCA pieces/block. The findings of this study provide more insight into how organics leached from woods significantly reduce the toxic effects of Cu ions against Gram-positive Bacillus species.

Biofilms affecting progression of mild steel corrosion by Gram positive Bacillus sp.

The biodeterioration of metals have detrimental effects on the environment with economic implications. The deterioration of metals is of great concern to industry. In this study, mild steel coupons which were immersed in a medium containing Gram-positive Bacillus spp. and different nutrient sources were compared with the control in sterile deionized water. The weight loss of the coupons in the presence of Bacillus spp. alone was lower than the control and was further reduced when additional carbon sources, especially fructose, were added. The level of metal corrosion was significantly increased in the presence of nitrate with or without bacteria. There was a significant strong correlation between the weight loss and biofilm level (r = 0.64; p < 0.05). The addition of nitrate and Bacillus spp. produced more biofilms on the coupons and resulted in greater weight loss compared to that with Bacillus spp. only under the same conditions. However, Bacillus spp. enriched with carbon sources formed less biofilms and results in lower weight loss compared to that with Bacillus spp. only. The production of biofilm by Bacillus spp. influences the level of metal corrosion under different environmental conditions, thereby, supporting the development of a preventive strategy against corrosion.

Erysipelothrix Bacteremia; is Endocarditis a Rule?

Erysipelothrix rhusiopathiae is a Gram-positive bacillus, a zoonotic pathogen rarely causing human infections ranging from localized skin infections to invasive infections such as endocarditis. In this report, we present two cases of Erysipelothrix bacteremia. The first case is a native valve tricuspid endocarditis, which is a highly unusual valve to be involved. The second case is bacteremia, probably secondary to a minor skin breach, which did not involve heart valves. Erysipelothrix bacteremia is considered highly associated with infective endocarditis and a high mortality rate, which could be a bias due to underreporting of Erysipelothrix bacteremia without endocarditis. Erysipelothrix is intrinsically resistant to vancomycin, the first-line agent for Gram-positive bacteremia. Both the patients in this report were treated successfully with ceftriaxone.

Nocardia niwae Disseminated Nocardiosis: A Novel Species Presenting Concurrently With Lung Adenocarcinoma.

Nocardia includes over 90 species of filamentous gram-positive bacilli that may cause disease in immunocompromised or immunocompetent hosts. Presentations may include pulmonary, 4, cutaneous, or disseminated infections. Tissue diagnosis may be required as it may mimic alternative etiologies. There is a paucity of data regarding rarer species of Nocardia. Intraspecies variability in antimicrobial susceptibility limits many treatment regimens to in-vitro activity data and treatment regimens often must be tailored to individual patients based on microbiologic cultures. We describe the case of a 63-year-old female who presented with disseminated Nocardia niwae, a species that was previously first identified in Florida for which little clinical data is known, along with concurrent lung adenocarcinoma with pulmonary and central nervous system lesions. Typical susceptibility patterns are discussed along with potential side effects of antimicrobial therapy.

Native Knee Septic Arthritis Due to Cutibacterium acnes: A Case Report.

Commensal skin anaerobes have been described as causative agents of prosthetic joint infections. Infection of native joints by these agents are, however, less common. We present the case of a 34-year-old male with recurrent joint effusion following closed trauma to the knee, four years ago, refractory to corticosteroid injections and several arthrocenteses. A synovial biopsy revealed Cutibacterium acnes infection leading to antibiotic therapy with clindamycin, and the patient was referred to orthopaedic and submitted to arthroscopic lavage. Atypical cartilage lesions, resembling the "growth of bacterial colonies", were found in the tibial plateaus with repeated isolation of C. acnes. Inpatient treatment with penicillin and vancomycin was conducted, followed by an oral course of amoxicillin, with no further registered recurrences. In this case, the authors describe a rare cause of native knee septic arthritis while highlighting the importance of repeated microbiology studies and adequate collection technique and sample handling, in order to better ascertain whether the isolated agent represents a contaminated sample or a true infection.

Trueperella bernardiae bloodstream infection following onco-gynaecologic surgery and literature review.

Trueperella bernardiae is a Gram-positive commensal bacillus of the human skin and oropharynx. It is known as an opportunistic human pathogen causing surgical wound, skin, and soft tissue, osteoarticular, and bloodstream infections (BSIs) with severe complications. We report a case of surgical wound related T. bernardiae BSI following onco-gynaecologic surgery together with a comprehensive literature review of T. bernardiae infections to alert clinicians about this emerging pathogen.

Intracranial Hemorrhage Associated With Listeria monocytogenes Bacteremia in an Elderly Patient on Mycophenolate Mofetil.

Listeria monocytogenes is an important foodborne bacterial pathogen in immunosuppressed patients, pregnant women, and individuals at the extremes of age, including neonates and older adults. Invasion of the central nervous system (CNS) and bacteremia are the principal clinical manifestations of infection in these hosts. In contrast, normal hosts who ingest high numbers of Listeria may develop self-limited febrile gastroenteritis. Hydrocephalus and intracranial hemorrhage (ICH) are very rare and severe complications of L. monocytogenes infection. ICH associated with L. monocytogenes has been reported even less frequently than hydrocephalus, with most cases occurring in the pediatric population. In this paper, we present a case of L. monocytogenes bacteremia in a 71-year-old male, complicated by intracranial hemorrhage. He presented at first with nonspecific symptoms of generalized weakness and fatigability and later developed drowsiness, disorientation, and fever, which prompted further investigations that revealed the presence of ICH and L. monocytogenes bacteremia.

Lawsonella clevelandensis is a rare cause of infected chronic contained rupture of abdominal aortic aneurysm.

Lawsonella clevelandensis is an anaerobic, partially acid-fast, Gram-positive bacillus associated with abscess formation. We present the case of a 70-year-old male with chronic contained rupture of abdominal aortic aneurysm (CCR-AAA) complicated by intra-abdominal abscess formation. An abdominal computed tomography scan revealed a rim-enhancing retroperitoneal collection tracking into the subcutaneous layer of the left flank and buttock, suggestive of CCR-AAA with infected haematoma. He underwent ultrasound-guided needle aspiration of the intra-abdominal collection. Conventional culture techniques failed to isolate L. clevelandensis , and the diagnosis was only confirmed by means of 16S rRNA PCR. The patient underwent branched endovascular repair of his aneurysm, and was commenced on treatment with co-amoxiclav, resulting in significant reduction in the size of the infected collection. This is only the second reported case of infection with L. clevelandensis in the UK, and the first reported case of this organism causing infected CCR-AAA.

Vacancy-Enhanced Photothermal Killing of Bacteria Mediated by Graphene Oxide.

With the emergence of antibiotic resistance, the development of efficient antimicrobial agents has become increasingly important. Graphene oxide (GO) has been used as an antibacterial agent, but how to realize and improve the antibacterial properties of GO is still required critically. Herein, we prepared two GO samples, abbreviated as GO-V11 and GO-V9. Positron annihilation spectra showed that they possessed predominantly VCCCCCCCCCCC (V11C) and VCCCCCCCCC (V9C) carbon vacancies, respectively. Their photothermal antibacterial properties were measured against Gram-negative Escherichia coli (E. coli) and Gram-positive Bacillus subtilis (B. subtilis) by using colony-forming unit and liquid optical density assays. GO-V9 displayed a higher photothermal antibacterial efficiency toward the two bacteria than GO-V11 because GO-V9 had a higher photothermal conversion efficiency (PTCE) (57.3%) than GO-V11 (42.5%). To reveal the difference in their PTCEs and antibacterial efficiencies, their energy band structures were tested with density functional theory calculations. The different vacancies changed the energy band structure from the indirect band gap of GO-V11 to the quasi-metallic band gap of GO-V9. The quasi-metallic band gap showed the higher PTCE, so we revealed the importance of the band gap of GO for its antibacterial mechanism. Tuning the vacancy properties is promising for improving the photothermal antibacterial efficiency.

Listeria monocytogenes meningitis.

Tumbling motility is one of the useful characteristics of Listeria monocytogenes. This can be helpful to identify the causative pathogen along with Gram staining before the confirmatory microbiological examination.

Erysipelothrix rhusiopathiae bacteremia: a challenging diagnosis!

Erysipelothrix rhusiopathiae, a Gram-positive bacillus, is reported to cause for cutaneous infections and endocarditis. We report a case of E. rhusiopathiae bacteremia without severe clinical illness. The patient, a 74-year-old man, is suffering from a chronic lymphoid leukemia (LLC). Following a trauma, the patient developed a bruise on the left inch. Because the site of shock seemed clinically infected, oral amoxicilline-acid clavulanic (AAC) treatment was started after withdrawn 1 set of blood cultures. These blood culture specimens yielded a Gram-positive bacillus identified as E. rhusiopathiae by mass spectrometry MALDI-TOF (Microflex Brüker). The strain was sensitive to beta-lactam, fluoroquinolones and macrolides, resistant to vancomycin (natural resistance), and amikacin but sensitive to gentamicin. After 5 days of treatment by AAC, the patient became apyretic. One year after this episode, we reported no further symptoms of infection, or endocarditis. The natural resistance of E. rhusiopathiae in glycopeptides underlines the importance of a microbiological diagnosis. Indeed, vancomycine can be the treatment of first intention in Gram-positive bacillus bacteremia. The identification of bacteria using mass spectrometry is available the same day of the blood culture positivity and allows to prescribe the most adapted antibiotic treatment for the patient.