Bloodstream infection with pandrug-resistant Alcaligenes faecalis treated with double-dose of tigecycline

Alcaligenes faecalis promotes colitis to colorectal cancer transition through IgA+ B cell suppression and vinculin acetylation

Lymphoid tissue-resident commensal bacteria (LRC), a subtype of gut microbiota essential for inflammation-associated carcinogenesis, predominantly attribute to colorectal cancer(CRC), whereas its role was largely unknown. Herein, we found Alcaligenes faecalis (A. faecalis), the main LRC embedded in Peyer's patches, was abundantly enriched in colitis, adenoma, and stage-dependently observed in CRC tissues. Interestingly, A. faecalis alone can not affect intestinal homeostasis, while during colitis, A. faecalis significantly translocated from Peyer's patches to colon, remarkably attenuated immune response abilities of B cells, T cells, and DC cells in PPs, consequently impeded IgA+ B cells homing. Meanwhile, during colitis, the ectopia of A. faecalis in colon tissues, promoted vinculin acetylation by A. faecalis-derived metabolite acetic acid, which impeded intestinal barrier via hindering the binding of vinculin to β-catenin. Our study revealed A. faecalis not only suppress mucosal immune responses via reducing IgA+ B cells in Peyer's patches but also disrupt intestinal barrier via increasing vinculin acetylation, ultimately promoting inflammation-to-cancer transition in CRC.

Alcaligenes faecalis, Stenotrophomonas maltophilia, and Pseudomonas aeruginosa in a Mixed Microbial Contact Lens Keratitis: A Case Report

We present a case of mixed microbial keratitis in an otherwise healthy contact lens wearer. The microbes detected on microscopy included Pseudomonas aeruginosa, Acanthamoeba, Alcaligenes faecalis, and Stenotrophomonas maltophilia. P. aeruginosa and Acanthamoeba are well-recognised corneal pathogens, although S. maltophilia is uncommon, and A. faecalis is extremely rare. We were only able to find one previously reported case of A. faecalis keratitis, in a cornea that was otherwise compromised by ocular cicatricial pemphigoid. To the best of our knowledge, this case represents the second reported case of A. faecalis keratitis, and the first one in the context of a mixed microbial contact lens-related keratitis.

First-Genome Sequence Data of an Alcaligenes nematophilus Strain EBU-23 Encoding bla Gene Implicated in Acute Childhood Gastroenteritis

Although an environmental contaminant, Alcaligenes sp. are now increasingly reported in clinical infections. Here, we present a whole-genome sequence of an extended spectrum beta-lactamase (ESBL) Alcaligenes nematophilus strain EBU-23 encoding beta-lactamase, bla gene, isolated from the stool of a hospitalized infant with acute gastroenteritis in a tertiary hospital in Nigeria. Antibiotics susceptibility test revealed that the isolate was resistant to the β-lactams, cephalosporins, and penicillin, β-lactam combination, and the fluoroquinolones. Genomic analysis exposed the presence of a class A beta-lactam hydrolase gene and multiple multidrug efflux permease which may be responsible for the beta-lactamase and multidrug resistance observed with the isolate. To the best our knowledge, we describe the first whole-genome sequence of a multidrug-resistant A. nematophilus implicated in acute childhood gastroenteritis in Nigeria.

EFFECT OF PENICILLIUM SPECIES ON THE ANTIBIOTIC RESISTANCE PROFILE OF ALCALIGENES FAECALIS

Background

Infectious diseases due to antibiotic resistant pathogens are a global public health problem. This study aimed at determining the potential effect of bacterial-fungal interaction on the antibiotic susceptibility profile of Alcaligenes faecalis.

Materials and Methods

Alcaligenes faecalis was isolated from water samples. The isolate was identified using the conventional biochemical tests and the 16S rRNA molecular sequencing technique. Additionally, Penicillium species was isolated and identified based on colony morphological characteristics and microscopic features. Standardized isolates were co-cultured in broth medium. Antibiotic susceptibility evaluation of the Alcaligenes faecalis from the co-culture and the original Alcaligenes faecalis was carried out using the Kirby bauer disk diffusion method.

Results

The antibiotic susceptibility profile of Alcaligenes faecalis before and after co-culture remained largely unchanged except in the case of chloramphenicol, where the isolate showed reduced susceptibility. Molecular analysis of resistance gene revealed the absence of tested gene encoding antibiotic resistance, including the streptomycin resistance (str) genes (stra and strb) and the erythromycin resistance methylase (erm) gene.

Conclusion

The result of this study showed that there is a minimal influence of Penicillium cultures on the susceptibility of A. faecalis. Further research involving a wide spectrum of microorganisms and their interactions should be conducted to acquire a thorough understanding of the influence of microbial interactions on antibiotic susceptibility profiles in order to pave way for novel strategies to combat antimicrobial resistance.

Antimicrobial Resistance in Papua New Guinea: A Narrative Scoping Review

Antimicrobial-resistant bacterial infections are a known threat to the public health of low-income countries and are undercharacterized in Papua New Guinea. A scoping literature review of scientific peer-reviewed publications on antimicrobial resistance in Papua New Guinea was conducted, and their results were summarized. Many of the available data on resistant bacteria in Papua New Guinea have come from Port Moresby and Goroka and have been focused on Staphylococcus aureus, as well as important pediatric pathogens such as Streptococcus pneumoniae and Haemophilus influenzae. Progressive resistance to the commonly used antibiotics penicillin and chloramphenicol among most clinically important bacterial pathogens has prompted healthcare workers to adopt expensive broad-spectrum antibiotics. There is already evidence of resistance to newly adopted antibiotics among several Gram-negative organisms. Drivers of antimicrobial resistance in Papua New Guinea include a high burden of infectious diseases, inappropriate antibiotic prescription practices, poor regulation of antibiotics, incomplete adherence, substandard drug quality, and overcrowding of healthcare facilities. There is a lack of information on antimicrobial resistance among priority pathogens and from several important regions of Papua New Guinea.

Microbiota Assessment of Fresh-Cut Apples Packaged in Two Different Films

The aim of this work was to assess the natural microbiota of packed fresh-cut apples during refrigerated storage. Two different films were tested for the package, a biodegradable (PLA) film and a conventional and commercial one (OPP). Two antioxidant additives were applied, a natural olive pomace extract and the commercial ascorbic acid used by the industries. The results revealed lower bacteria counts in samples with olive pomace extract and PLA films than in those with ascorbic acid and OPP films after 5 and 12 days of storage. These findings suggest that the use of such natural extracts as additives in fruits could delay the growth of mesophilic bacteria. The characterization and identification of the bacterial isolates from fresh-cut apple samples showed that the most prevalent species were Citrobacter freundii, Staphylococcus warneri, Pseudomonas oryzihabitans, Alcalinogenes faecalis, Corynebacterium jeikeium, Micrococcus spp., Pantoea aglomerans and Bacillus spp. Furthermore, an increase in the microbial diversity during the storage time at refrigerated temperatures was observed, except for the sample treated with olive pomace extract and packaged in OPP film. The highest microbial diversity was found for samples with ascorbic acid as an additive. This could indicate a negative effect of ascorbic acid on the microbial inhibition of apple slices. The natural olive pomace extract demonstrated potential as an antimicrobial additive for fresh-cut apples.

Right Lower Extremity Osteomyelitis With Alcaligenes faecalis in a Patient With Poorly Controlled Type 2 Diabetes Mellitus

Alcaligenes faecalis (A. faecalis) is a Gram-negative, rod-shaped, oxidase(+) and catalase(+), obligate aerobe commonly found in soil or water. It has also been found in human intestinal microbiota and more rarely in hospital settings and is typically associated with opportunistic infections. Although it has intrinsic resistance to many commonly used antibiotics, it is increasingly found to have developed antibiotic resistance. We present a rare case of A. faecalis osteomyelitis in a patient with a chronic diabetic foot ulcer.

Epidemiology, Drug Resistance, and Risk Factors for Mortality Among Hematopoietic Stem Cell Transplantation Recipients with Hospital-Acquired Klebsiella pneumoniae Infections: A Single-Center Retrospective Study from China

Objective

Infection is the most common complication and cause of death after hematopoietic stem cell transplantation (HSCT). Our study aims to investigate the clinical characteristics and risk factors for death of Klebsiella pneumoniae infections in HSCT recipients, so as to provide evidence for guiding antibiotic use and improving prognosis in the future.

Methods

The epidemiology, clinical manifestations and drug resistance rate with K. pneumoniae infections among HSCT recipients between January 1, 2012 and September 30, 2021 were retrospectively reviewed. Logistic regression model and Cox regression model were respectively used to determine the risk factors for carbapenem-resistant Klebsiella pneumoniae (CRKP) acquisition and death.

Results

Fifty-nine HSCT recipients suffered from K. pneumoniae infections, with a mortality rate of 42.4%. The most common site was lung, followed by blood stream. The resistance rate of K. pneumoniae to various clinically common antibiotics was high, especially CRKP, which was only sensitive to amikacin and tigecycline. Independent risk factor for CPKP acquisition was a previous infection within 3 months before transplantation (OR=10.981, 95% CI 1.474-81.809, P=0.019). Independent risk factors for mortality included interval from diagnosis to transplantation > 180 days (HR=3.963, 95% CI 1.25-12.561, P=0.019), engraftment period > 20 days (HR=8.015, 95% CI 2.355-27.279, P=0.001), non-use of anti-CMV immunoglobulin/rituximab after transplantation (HR=10.720, 95% CI 2.390-48.089, P=0.002), and PCT > 5 μg/L (HR=5.906, 95% CI 1.623-21.500, P=0.007).

Conclusion

K. pneumoniae infection has become a serious threat for HSCT recipients, which reminds us to pay enough attention and actively seek new strategies.

Pulmonary Dysfunction Augmenting Bacterial Aerosols in Leather Tanneries of Punjab, Pakistan

BACKGROUND

Particulate matter-associated microbes in the workplace are a burning issue in occupational toxicology. Studies have reported on respiratory infections among tannery cohorts. This study uniquely presents measurements of airborne bacterial concentrations associated with varied particulate-matter sizes, their exposure, and consequent severity in occupational respiratory problems, all for different microenvironments within leather tanneries.

METHODS

Analyses included molecular identification of isolates, computation of mass median aerodynamic diameter of aerosols, tannery process-exposure dose (TPED) to bacterial aerosols, and spirometry and symptom assessment of impaired pulmonary function.

RESULTS

The highest bacterial concentrations were for rawhide treatment and finishing units, showing 3.6×103 and 3.7×103 CFU/m3, respectively. Identified bacterial species included Ochrobactrum pseudogrignonense, Neisseria bacilliformis, Enterobacter cloacae, Alcaligenes faecalis, Klebsiella pneumoniae, and Corynebacterium spp. Maximum and minimum values of mass median aerodynamic diameter were 8.3 µm and 0.65 µm for buffing and snuffing and production units, respectively. The highest TPED was 1,516.9 CFU/kg for finishing units. Respiratory symptoms in order of incidence were dyspnea > phlegm > cough > wheezing and tachypnea (equivalent). Bronchodilator measurements of FEV1, FVC, and PEF represent decline in lung function. Of 26 patients identified with COPD, most were working in rawhide treatment.

CONCLUSION

We conclude that exposure-infection synergy is also a cause of pulmonary ailments and COPD development, rather than the better-known exposure-smoking synergy.

Antibacterial Activity of Biosynthesized Selenium Nanoparticles Using Extracts of Calendula officinalis against Potentially Clinical Bacterial Strains

The use of selenium nanoparticles (SeNPs) in the biomedical area has been increasing as an alternative to the growing bacterial resistance to antibiotics. In this research, SeNPs were synthesized by green synthesis using ascorbic acid (AsAc) as a reducing agent and methanolic extract of Calendula officinalis L. flowers as a stabilizer. Characterization of SeNPs was performed by UV-vis spectrophotometry, infrared spectrophotometry (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) techniques. SeNPs of 40–60 nm and spherical morphologies were obtained. The antibacterial activity of marigold extracts and fractions was evaluated by disk diffusion methodology. The evaluation of SeNPs at different incubation times was performed through the colony-forming unit (CFU) count, in both cases against Serratia marcescens, Enterobacter cloacae, and Alcaligenes faecalis bacteria. Partial antibacterial activity was observed with methanolic extracts of marigold leaves and flowers and total inhibition with SeNPs from 2 h for S. marcescens, 1 h for E. cloacae, and 30 min for A. faecalis. In addition, SeNPs were found to exhibit antioxidant activity. The results indicate that SeNPs present a potentiated effect of both antimicrobial and antioxidant activity compared to the individual use of marigold extracts or sodium selenite (Na₂SeO₃). Their application emerges as an alternative for the control of clinical pathogens.

Extensively drug-resistant Alcaligenes faecalis infection

Background

Alcaligenes faecalis is usually causes opportunistic infections in humans. Alcaligenes faecalis infection is often difficult to treat due to its increased resistance to several antibiotics. The results from a clinical study of patients with Alcaligenes faecalis infection may help improve patients’ clinical care.

Methods

We conducted a retrospective analysis of all patients presenting with Alcaligenes faecalis infection from January 2014 to December 2019. The medical records of all patients were reviewed for demographic information, clinical symptoms and signs, comorbidities, use of intravenous antibiotics within the past three months, bacterial culture, antibiotics sensitivity test, and clinical outcomes.

Results

Sixty-one cases of Alcaligenes faecalis infection were seen during the study period, including 25 cases of cystitis, nine cases of diabetic foot infection, eight cases of pneumonia, seven cases of acute pyelonephritis, three cases of bacteremia, and nine cases of infection at specific sites. Thirty-seven patients (60.7%) had a history of receiving intravenous antibiotics within three months of the diagnosis. Fifty-one (83.6%) cases were mixed with other bacterial infections. Extensively drug-resistant infections have been reported since 2018. The best sensitivity rate to Alcaligenes faecalis was 66.7% for three antibiotics (imipenem, meropenem, and ceftazidime) in 2019. Two antibiotics (ciprofloxacin and piperacillin/tazobactam) sensitivity rates to A. faecalis were less than 50%.

Conclusions

The most frequent Alcaligenes faecalis infection sites, in order, are the bloodstream, urinary tract, skin and soft tissue, and middle ear. The susceptibility rate of Alcaligenes faecalis to commonly used antibiotics is decreasing. Extensively drug-resistant Alcaligenes faecalis infections have emerged.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05557-8.

Bacillus subtilis TR47II as a source of bioactive lipopeptides against Gram-negative pathogens causing nosocomial infections

This study aimed to investigate the antimicrobial, antibiofilm, and cytotoxic effects of biosurfactant lipopeptides synthesized by Bacillus subtilis TR47II. For this purpose, the lipopeptides were partially purified using a three-step process and characterized. In the first step, the crude extract obtained from acid precipitation exhibited strong antibacterial activity against the Gram-negative opportunistic pathogens Alcaligenes faecalis ATCC 8750, Achromobacter xylosoxidans ATCC 13138, Pseudomonas alcaligenes ATCC 14909, and Pseudomonas putida ATCC 15175. Moreover, partial inhibition was observed against Klebsiella aerogenes ATCC 13048 (42%), Escherichia coli ATCC 25922 (16%), and Pseudomonas aeruginosa ATCC 27853 (47%). The lipopeptides in the crude extract were extracted with methanol and fractioned on a silica gel chromatography column, rendering four TLC-pooled chromatographic fractions, named F1, F2, F3, and F4. The chromatographic fraction F4 was the most bioactive, with MIC values between 300 and 600 µg mL^-1. Besides, F4 at sub-MIC doses dislodged the biofilms of A. faecalis, A. xylosoxidans, and P. alcaligenes by about 100, 85, and 81%, respectively. No cytotoxic effect was observed in mammalian cells at MIC. MALDI-TOF-MS analysis revealed that F4 contained cyclic lipopeptides belonging to two families: iturins (m/z 1004 to 1087) and fengycins (m/z 1424 to 1545). The dual effect of F4 on planktonic and sessile growth could suggest that the synergistic application of these biosurfactants could be efficient in the control of these opportunistic pathogens.

First whole genome sequence of Paenalcaligenes suwonensis bearing blaVIM-5 Metallo-β-lactamase: A clinical isolate responsible for acute gastroenteritis

Carbapenemase-producing Alcaligenes species has been described in only few studies, with none so far from the African continent. Here, we report the whole genome sequence of Peanalcaligenes suwonensis bearing bla_VIM-5 metallo-β-lactamase and first detection of carbapenemase producing Alcaligenes faecalis isolated from patients attending tertiary healthcare facilities in Nigeria. The isolates were identified by MALDI-TOF Mass Spectrometry. Antibiotic susceptibility assay, modified Carba NP test and genomic investigation revealed that two isolates of Alcaligenes faecalis and an isolate of Paenalcaligenes suwonensis harboured bla_VIM-5 gene. The genome sequence analysis of the P. suwonensis 191B isolate, responsible for acute gastroenteritis, reveal the presence of 18 antibiotic resistance genes coding for resistance to five different classes of antibiotics. Three of the genes (bla_OXA-368, bla_CARB-4 and bla_VIM-5) codes for resistance to β-lactam antibiotics. To our best knowledge, we describe here the first genome sequence of P. suwonensis species and the first detection of class B carbapenemase bla_VIM-5 in a clinical isolate of P. suwonensis species and Alcaligenes faecalis in Nigeria. The finding of this study is of concern, as lateral dissemination of the genes into clinically important Gram-negative pathogens is highly likely.

Rare but Fatal Case of Cavitary Pneumonia Caused by Alcaligenes Faecalis

Alcaligenes faecalis is a gram-negative bacterium that is commonly found in the environment. This pathogen is usually transmitted in the form of droplets through ventilation equipment and nebulizers, but transmission through direct contact has also been documented in few case reports. This pathogen can cause rare but fatal infections including appendicitis, abscesses, meningitis, bloodstream infection, endocarditis, and post-operative endophthalmitis. Pan drug resistance to all commercially available antibiotics has been emerging globally. We present the case of a 66-year-old male who had respiratory failure along with multiple comorbidities. A large cavitary lesion caused by pan drug-resistant Alcaligenes faecalis was found on chest imaging. Despite the treatment with broad-spectrum antibiotics, the clinical outcome was very poor.

Diabetic Foot Ulcer with Infection

<b><i>Background:</i></b> Diabetic foot ulcers are an increasingly common complex problem and are associated with a very considerable health care burden. Diabetic foot ulcer with <i>Alcaligenes faecalis</i> infection is rarely reported in the literature. We report a case series of diabetic foot ulcer with <i>A. faecalis</i> infection treated at our facility. <b><i>Methods:</i></b> We conducted a retrospective analysis of all patients with diabetic foot ulcer with <i>A. faecalis</i> infection seen from January 2014 to April 2019. We analyzed the clinical characteristics, ulcer lesion classification, comorbidities, prior intravenous antibiotic use within 3 months, wound culture, antibiotics sensitivity test, and clinical outcomes of these patients. <b><i>Results:</i></b> Eight cases of diabetic foot ulcer with <i>A. faecalis</i> infection were seen in 5 males and 3 females. Mean age was 54.6 years. All patients had other comorbidities, and all ulcer lesions were of chronic duration (&#x3e;14 days). All wound cultures revealed polymicrobial infection, with 2 cases of diabetic foot with extensive drug-resistant <i>A. faecalis</i> infection found in 2019. All patients needed intravenous antibiotic therapy and surgical interventions for the chronic ulcer lesion. The wound failed to heal in 3 patients. <b><i>Conclusions:</i></b> All diabetic foot ulcers with <i>A. faecalis</i> infection were of chronic duration (&#x3e;14 days) and had polymicrobial infection. Extensive drug-resistant <i>A. faecalis</i> emerged in 2019. Definitive antibiotic therapy is necessary for all infected wounds and should be based on both the culture results and susceptibility data. All patients will need appropriate wound care, and most will need rapid surgical intervention for an optimal outcome.