Intraperitoneal development of the filarial nematode Brugia malayi in the Mongolian jird (Meriones unguiculatus)

In the present study, we describe intraperitoneal development of the FR3 strain of Brugia malayi in Mongolian jirds (Meriones unguiculatus). The third molt for male worms occurred between 4 and 7 days postinfection (dpi) and between 4 and 8 dpi for females. The fourth and final molt occurred between days 21 and 29 for males and 25 and 34 for females, considerably earlier than the times reported for subcutaneous infection models using cats and jirds. The timing of the third molt coincided largely with reports for subcutaneous Brugia pahangi infections of cats and jirds, but the final molt occurred considerably later and lasted longer than those reported for subcutaneous B. pahangi models. Spermatogenesis occurred by at least 50 dpi in adult males, and insemination of females likely occurred between 50 and 60 dpi. Microfilariae were observed in the uteri and ovejectors of adult females at 65 dpi.     

Preparation and in vitro delivery performance of chitosan–alginate microcapsule for IgG

The study aimed to develop chitosan–alginate microcapsule as an oral delivery carrier for IgG. Bovine serum albumin (BSA) was used as the protein to be encapsulated while determining the microcapsule formula by evaluating encapsulation efficiency (EE), loading capacity (LC) and release profile. Results suggested that the optimal formula was composed of 0.1% chitosan, 0.5% CaCl₂, 2% sodium alginate and the loading rate of BSA reached 25%. IgG was substituted for BSA and an IgG microcapsule was prepared following the above formula. The EE and LC of the resulted IgG microcapsule reached 76.83% and 18.53%. After 2?h incubation in simulated gastric fluid, the activity of IgG in the microcapsule remained at 79.79% and the total release rate of IgG in a simulated intestinal fluid reached 82.52%. This encapsulation formula was proved to be an effective oral delivery system which would protect the IgG from severe gastric conditions and guarantee an efficient release in the intestinal tract.     

Field tests demonstrating reduced activity of ivermectin and moxidectin against small strongyles in horses on 14 farms in Central Kentucky in 2007–2009

Efficacy of ivermectin (IVM) and moxidectin (MOX) against small strongyles was evaluated in horses (n = 363) in field tests on 14 farms in Central Kentucky between 2007 and 2009. Most of the horses were yearlings but a few were weanlings and mares. The number of horses treated with IVM was 255 and those treated with MOX was 108. Horses on six farms were allotted into two groups. One group was treated with each of the two drugs, whereas horses on the other eight farms were treated with only one of the two drugs—IVM on six farms and MOX on two farms. Strongyle eggs per gram of feces (EPGs) compared to initial use of IVM and MOX returned almost twice as quickly after treatment of horses on all of the farms. IVM has been used much more extensively in this geographical area than MOX. Reduced activity of MOX was evident even on farms with rare or no apparent previous use of MOX but with probable extensive use of IVM.     

Toll-like receptor- and filarial antigen-mediated, mitogen-activated protein kinase- and NF-κB-dependent regulation of angiogenic growth factors in filarial lymphatic pathology

Filarial lymphatic pathology is of multifactorial origin, with inflammation, lymphangiogenesis, and innate immune responses all playing important roles. The role of Toll-like receptors (TLRs) in the development of filarial pathology is well characterized. Similarly, the association of pathology with elevated levels of plasma angiogenic factors has also been documented. To examine the association between TLR function and the development of lymphangiogenesis in filarial infections, we examined TLR- and filarial antigen-induced expression and production of various angiogenic growth factors. We demonstrate that TLR ligands (specifically TLR2, -3, and -5 ligands) induce significantly increased expression/production of vascular endothelial growth factor A (VEGF-A) and angiopoietin-1 (Ang-1) in the peripheral blood mononuclear cells of individuals with lymphatic pathology (CP individuals) compared to that in cells of asymptomatic infected (INF) individuals. Similarly, filarial antigens induce significantly enhanced production of VEGF-C in CP compared with INF individuals. TLR2-mediated enhancement of angiogenic growth factor production in CP individuals was shown to be dependent on mitogen-activated protein kinase (MAPK) and NF-κB signaling, as pharmacologic inhibition of either extracellular signal-regulated kinase 1/2 (ERK1/2), p38 MAPK, or NF-κB signaling resulted in significantly diminished production of VEGF-A and Ang-1. Our data therefore strongly suggest an important association between TLR signaling and lymphangiogenesis in the development of pathology in human lymphatic filariasis.     

Anticarcinogenic activity of kalpaamruthaa,a modified Siddha preparation,against aflatoxin–B1-induced hepatocellular carcinoma in rats

To investigate the potential anticancer effect of kalpaamrutha (KA), a modified Siddha preparation, against aflatoxin–B₁(AFB₁)-induced hepatocellular carcinoma (HCC) in rats, KA (200 mg/kg body weight/day) was administered to AFB₁-induced (2 mg/kg body weight i.p.) HCC rats, orally for 28 days. At the end of the experimental period, changes in body weight were recorded; the levels of alpha-fetoprotein and total protein was estimated in the serum; activities of marker enzymes were assayed in serum and total protein; DNA and RNA contents were estimated in liver tissue; activities of glycolytic enzymes, mitochondrial Krebs cycle enzymes, and respiratory chain enzymes were assayed in liver tissue of control and experimental rats. Further histopathological examination of the liver sections was carried out to support the anticancer effect of KA against AFB₁-induced HCC. Administration of KA overall increase in glycolytic enzymes with a subsequent reduction in gluconeogenic enzymes, mitochondrial Krebs cycle enzymes, and respiratory chain enzymes was observed in HCC-induced rats. These altered enzyme activities were effectively counteracted by supplementation with KA and also prevented the body weight loss by enhancing the host energy metabolism. Histological studies supported the biochemical findings. The results of the present study reveal that the drug KA has potential anticancer effect against AFB₁-induced HCC rats.     

Adhesion,migration and mechanics of human adipose-tissue-derived stem cells on silk fibroin–chitosan matrix

Silk fibroin–chitosan (SFCS) scaffold is a naturally derived biocompatible matrix with potential reconstructive surgical applications. In this study, human adipose-derived mesenchymal stem cells (ASCs) were seeded on SFCS scaffolds and cell attachment was characterized by fluorescence, confocal, time-lapse, atomic force, and scanning electron microscopy (SEM) studies. Adhesion of ASCs on SFCS was 39.4 ± 4.8% at 15 min, increasing to 92.8 ± 1.5% at 120 min. ASC adhered at regions of architectural complexity and infiltrate into three-dimensional scaffold. Time-lapse confocal studies indicated a mean ASC speed on SFCS of 18.47 ± 2.7 μm h^?1 and a mean persistence time of 41.4 ± 9.3 min over a 2.75 h study period. Cytokinetic and SEM studies demonstrated ASC–ASC interaction via microvillus extensions. The apparent elastic modulus was significantly higher (p < 0.0001) for ASCs seeded on SFCS (69.0 ± 9.0 kPa) than on glass (6.1 ± 0.4 kPa). Also, cytoskeleton F-actin fiber density was higher (p < 0.05) for ASC seeded on SFCS (0.42 ± 0.02 fibers μm^?1) than on glass-seeded controls (0.24 ± 0.03 fibers μm^?1). Hence, SFCS scaffold facilitates mesenchymal stem cell attachment, migration, three-dimensional infiltration, and cell–cell interaction. This study showed the potential use of SFCS as a local carrier for autologous stem cells for reconstructive surgery application.     

In vitro activity of nemonoxacin, tigecycline, and other antimicrobial agents against Helicobacter pylori isolates in Taiwan, 1998–2007

The minimum inhibitory concentrations (MICs) of 330 nonduplicate Helicobacter pylori isolates to nemonoxacin, tigecycline, and eight other antimicrobial agents were determined by using the agar dilution method. Sequencing the quinolone resistance-determining regions (QRDRs) in the gyrA gene of these isolates was also performed. Resistance to clarithromycin showed an increasing trend during the ten-year study period and was highest (38%) in 2005. Tigecycline had potent in vitro activities against all isolates, with an MIC₉₀ of 0.06 μg/ml. Among the quinolones tested, nemonoxacin (MIC₅₀ of 0.12 μg/ml and MIC₉₀ of 0.25 μg/ml) and gemifloxacin had one to two-fold better in vitro activities than ciprofloxacin, levofloxacin, and moxifloxacin. Among the nine isolates (2.7%) with levofloxacin resistance, four (44.4%) were also resistant to metronidazole, three (33.3%) to clarithromycin, and two (22.2%) to amoxicillin. Isolates with levofloxacin resistance exhibited one or two of three amino acid alterations (Ser-70, Asn-87, and Asp-91) involved in QRDRs in the gyrA gene. A double mutation at Ser70Cys and Asn87Ile had a higher level of resistance. The results of this study suggest a potentially useful role of nemonoxacin and tigecycline in the treatment of infections caused by H. pylori. The gyrA mutation at Ser-70 is a novel finding and has an impact on levofloxacin resistance.     

Characterization of hLF1–11 immobilization onto chitosan ultrathin films,and its effects on antimicrobial activity

hLF1–11 (GRRRRSVQWCA) is an antimicrobial peptide (AMP) with high activity against methicillin-resistant Staphylococcus aureus (MRSA), the most prevalent species in implant-associated infection. In this work, the effect of the surface immobilization on hLF1–11 antimicrobial activity was studied. Immobilization was performed onto chitosan thin films as a model for an implant coating due to its reported osteogenic and antibacterial properties. Chitosan thin films were produced by spin-coating on gold surfaces. hLF1–11 was immobilized onto these films by its C-terminal cysteine in an orientation that exposes the antimicrobial activity-related arginine-rich portion of the peptide. Two levels of exposure (with and without a polyethylene glycol (PEG) spacer) were analyzed. Covalent immobilization was further compared with the AMP physical adsorption onto chitosan films. Surfaces were characterized using ellipsometry, contact angle measurements, atomic force microscopy, infrared and X-ray photoelectron spectroscopies and using a fluorimetric assay for hLF1–11 quantification. Surface antimicrobial activity was assessed through surface adhesion and viability assays using an MRSA (S. aureus ATCC 33591). The incorporation of hLF1–11 increased significantly bacterial adhesion to chitosan films. However, the presence of hLF1–11, namely when immobilized through a PEG spacer, decreased the viability of adherent bacteria with regard to the control surface. These results demonstrated that hLF1–11 after covalent immobilization by its cysteine can maintain activity, particularly if a spacer is applied. However, further studies, exploring the opposite orientation or the same C-terminal orientation, but non-cysteine related, can help to clarify the potential of the hLF1–11 immobilization strategy.     

Comparative activity of ceftobiprole against coagulase-negative staphylococci from the BSAC Bacteraemia Surveillance Programme, 2013–2015

Coagulase-negative staphylococci (CoNS) are a significant cause of bacteraemia, the treatment of which is becoming increasingly complex due to the emergence of multidrug-resistant strains. This study aimed to evaluate the in vitro activity of ceftobiprole, an advanced-generation cephalosporin, as compared with other antimicrobial agents against CoNS from patients with bacteraemia. As part of the British Society for Antimicrobial Chemotherapy (BSAC) Bacteraemia Surveillance Programme, 650 blood isolates of CoNS were obtained from patients with bacteraemia at 74 centres throughout the UK and Ireland for the years 2013–2015. Minimum inhibitory concentrations (MICs) of ceftobiprole and other antimicrobial agents were determined using the BSAC agar dilution method. Susceptibility was assessed by European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. The majority of the isolates (63.2%) were Staphylococcus epidermidis. Overall, methicillin resistance, as determined by oxacillin susceptibility testing, was observed in 64.2% of isolates. The MIC_50/90 of ceftobiprole was 1/2 mg/L, and 100% of CoNS isolates were inhibited at the EUCAST ceftobiprole non-species-specific pharmacokinetic/pharmacodynamic breakpoint of 4 mg/L. Only one isolate was resistant to vancomycin. Overall rates of resistance to ciprofloxacin, clindamycin, erythromycin and teicoplanin were 50.5, 25.1, 68.2 and 20.9%, respectively. In S. epidermidis, resistance to oxacillin was associated with increased resistance to other antimicrobials. Ceftobiprole demonstrated in vitro activity against all CoNS species isolated from patients with bacteraemia and was active against species resistant to other antistaphylococcal antimicrobials. The collection of clinical data regarding the efficacy of ceftobiprole in treating CoNS bacteraemia is warranted.     

In vitro activity of aztreonam–avibactam against Enterobacterales isolates collected in Latin America,Africa/Middle East,Asia, and Eurasia for the ATLAS Global Surveillance Program in 2019–2021

This study aimed to report reference method antimicrobial susceptibility results for 24,937 recent (2019–2021) clinical isolates of Enterobacterales from 27 countries in Latin America, Eurasia, Africa/Middle East, and Asia with a focus on the investigational combination aztreonam–avibactam against metallo-β-lactamase (MBL) isolates. Antimicrobial susceptibility testing was performed by the CLSI broth microdilution methodology. Minimum inhibitory concentrations (MICs) were interpreted using the CLSI (2022) breakpoints for all agents except aztreonam–avibactam (provisional pharmacokinetic/pharmacodynamic susceptible breakpoint, ≤ 8 mg/L) and tigecycline (US-FDA). Molecular testing for β-lactamase genes was performed on isolates with meropenem MICs ≥ 2 mg/L, ceftazidime–avibactam MICs ≥ 16 mg/L, and/or aztreonam–avibactam MICs ≥ 16 mg/L, and 50% of isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Klebsiella variicola, and Proteus mirabilis testing with ceftazidime and/or aztreonam MICs ≥ 2 mg/L. Aztreonam–avibactam inhibited 99.8% of all Enterobacterales at ≤ 8 mg/L (MIC₉₀, 0.25 mg/L) and maintained activity against phenotypically resistant subsets of multidrug-resistant (MDR) (99.5% susceptible), extensively drug-resistant (XDR) (98.7%), and carbapenem-resistant Enterobacterales (CRE) (99.1%) isolates. At ≤ 8 mg/L, aztreonam–avibactam inhibited 100%, 99.6%, 99.6%, and 98.8% of KPC-, OXA-48-like-, ESBL-, and MBL-carrying isolates, respectively. MBL-positive isolates were most prevalent in India (20.5%), Guatemala (13.8%), and Jordan (13.2%). No differences in the activity of aztreonam–avibactam were observed across the global regions evaluated. At a concentration of ≤ 8 mg/L, aztreonam–avibactam inhibited almost all Enterobacterales collected from developing countries, including MBL-producing isolates. The widespread dissemination of MBLs among Enterobacterales highlights the unmet need for new agents such as aztreonam–avibactam for the treatment of CRE infections.

     

Long-term trends in the epidemiology of human leptospirosis (Slovak Republic, 1954–2006)

The purpose of this study was the observation of eventual shifts in some basic epidemiological features of human leptospirosis in Slovakia over a long period of time. Epidemiological traits of human leptospirosis were evaluated in three decades: 1954-1963 (822 cases), 1976-1985 (477 cases) and 1997-2006 (310 cases). The evaluation encompassed the aetiologic structure of cases, the incidence rate of diseases, men-to-women ratio of patients, as well as the professional and seasonal distribution of patients. The most affected feature was the incidence rate, which decreased by more than 70% over time. Another considerable change was the proportion of different major serological types of leptospirosis. The initially prevailing Sejroe infections fell to 4th place in the percentage rank, while Grippotyphosa disease, which was ranked 2nd place at the beginning of the observations, became dominating. Icterohaemorrhagiae disease climbed from 4th place to 2nd place. Third place was reserved by the Pomona?+?Tarassovi infections during the whole study period. A distinct tendency of age- and gender-specific incidence rate compared to the proportion of leptospirosis by age and gender was noticed; only minor alterations of the values of both parameters were registered over time. The overall value of the men-to-women ratio (MWR) of diseased persons was virtually within the same range in all three time periods but varied according to different age groups. The MWRs relative to the causal Leptospira serovars were stable over time but markedly differed among distinct serovars. Incidence rates related to age and aetiology showed different trends for the major serological types of leptospirosis. Changes were observed in the professional distribution of leptospirosis: there was an important proportional decrease of cases among farmers and field workers, an increase among house-wives?+?pensioners, but only some slight changes in abattoir workers/butchers, pupils?+?students and workers. The seasonal distribution of patients did not show any remarkable changes; the maximum percentage of cases occurred during the period extending from July to November during the whole period of observation. The epidemiological features of human leptospirosis underwent important shifts in the Slovak Republic over a 50-year period of time. They were very closely related to economical, social and political changes, which are discussed in this paper. The results may be useful for specialists in other European countries.     

Acetylcholinesterase secreted by Anisakis simplex larvae (Nematoda: Anisakidae) parasitizing herring,Clupea harengus: an inverse relationship of enzyme activity in the host–parasite system

Acetylcholinesterase (AChE) is a key enzyme involved in nerve impulse transmission in both vertebrates and invertebrates. In addition to neuromuscular AChE, many parasitic nematodes synthesize AChE in secretory glands and release the enzyme into their external environment. In this study, we evaluate the activities of both somatic and secreted AChE from larvae (L3) of the parasitic nematode Anisakis simplex, and compare these to the AChE activity in its host, herring, Clupea harengus. A. simplex larvae were obtained from a herring sampled in three areas of the southern Baltic. Enzyme kinetics were determined for excretory/secretory (E/S) products and somatic extracts of larvae as well as for herring muscle tissue. The results reveal that mean AChE activity is approximately fourfold higher in E/S products and eightfold higher in somatic extracts of post-secretory A. simplex larvae than in host muscle tissue. The level of AChE activity in nematodes is inversely related to the enzyme activity in their hosts, i.e. reduced AChE activity in herring was accompanied by increased enzyme activity in its parasites. The physiological function of AChE secreted by parasitic nematodes has been widely discussed in the literature, and numerous roles for this form of enzyme have been suggested. The results of our investigation indicate that AChE secretion by A. simplex larvae may constitute an adaptive mechanism that promotes survival under adverse environmental conditions. Larvae probably increase secretion of AChE in response to a direct and/or indirect effect of neurotoxic compounds. This is the first report of such a phenomenon in A. simplex.     

The role of evolutionarily conserved signalling systems in Echinococcus multilocularis development and host–parasite interaction

Alveolar echinococcosis, one of the most serious and life-threatening zoonoses in the world, is caused by the metacestode larval stage of the fox-tapeworm Echinococcus multilocularis. Mostly due to its accessibility to in vitro cultivation, this parasite has recently evolved into an experimental model system to study larval cestode development and associated host–parasite interaction mechanisms. Respective advances include the establishment of axenic in vitro cultivation systems for parasite larvae as well as culture systems by which the early development of metacestode vesicles from totipotent parasite stem cells can be reconstituted under controlled laboratory conditions. A series of evolutionarily conserved signalling molecules of the insulin, epidermal growth factor and transforming growth factor-β pathways that are able to functionally interact with corresponding host cytokines have been described in E. multilocularis and most likely play a crucial role in parasite development within the liver of the intermediate host. Furthermore, a whole genome sequencing project has been initiated by which a comprehensive picture on E. multilocularis cell–cell communication systems will be available in due time, including information on parasite cytokines that are secreted towards host tissue and thus might affect the immune response. In this article, an overview of our current picture on Echinococcus signalling systems will be given, and the potential to exploit these pathways as targets for anti-parasitic chemotherapy will be discussed.     

Short Article The Use of Mercury against Pediculosis in the Renaissance: The Case of Ferdinand II of Aragon,King of Naples, 1467–96

The hair samples of Ferdinand II of Aragon (1467–1496), King of Naples, whose mummy is preserved in the Basilica of San Domenico Maggiore in Naples, showed a high content of mercury, with a value of 827ppm. Furthermore, examination using a stereomicroscope and a scanning electron microscope (SEM) of head and pubic hairs of Ferdinand II, revealed a lice infestation. The reasons for the massive presence of the mercury in the king''s hair are discussed and contemporary literature regarding the use of this metal in medical therapies and in cosmetic practices is analysed. As a result, the high value of mercury in the hair of Ferdinand II can be attributed to antipediculosis therapy, applied as a topic medicament. This case represents an important finding for the history of medicine, because demonstrates that in the Renaissance mercury was applied locally not only to treat syphilis, as well attested by direct and indirect sources, but also to prevent or eliminate lice infestation.     

Systemic and extraintestinal forms of human infection due to non-typhoid salmonellae in Bulgaria, 2005–2010

The purpose of this investigation was to review the clinical cases diagnosed as systemic or extraintestinal salmonellosis between 2005 and 2010 in Bulgaria, to determine the antimicrobial resistance of the causative salmonellae, and to analyze the pulsed field gel electrophoresis (PFGE) profiles of extraintestinal Salmonella Corvallis isolates. Culture, biochemical tests, and serotyping were performed. Resistance to 12 antimicrobial agents was studied with the Bauer–Kirby disk diffusion method. The double-disk synergy method was used for the screening of the presence of extended-spectrum beta-lactamases (ESBLs). PFGE typing and analysis of the dendrogram was performed for the comparative investigation of Salmonella Corvallis isolates. Between 2005 and 2010, 2,227 human non-typhoid Salmonella isolates were investigated at the National Reference Laboratory of Enteric Pathogens, Sofia, Bulgaria. Thirty-three strains (1.48?%) from nine national regions were isolated from patients with systemic and extraintestinal forms of salmonellosis. The serotype distribution was as follows: S. enteritidis (n?=?21), S. choleraesuis (diphasic n?=?3; monophasic n?=?3), S. typhimurium (n?=?2), Salmonella Corvallis (n?=?2), Salmonella Montevideo (n?=?1), and S. javiana (n?=?1). Eight patients developed severe forms of infections: sepsis (n?=?2), septic shock (n?=?1 with fatal outcome), meningitis (n?=?3), and acute renal failure (n?=?2). Twenty-two percent of isolates were resistant to ampicillin and gentamicin, 17.64?% to tetracycline, 14.28?% to nalidixic acid, and 10?% to chloramphenicol. All isolates were susceptible to ciprofloxacin. One Salmonella Corvallis isolate recovered from a patient with chronic hemolytic anemia produced an ESBL and its PFGE profile demonstrated less than 96?% similarity to fecal and wound Salmonella Corvallis with susceptible phenotypes. S. enteritidis was the most common cause of systemic and extraintestinal forms of human salmonellosis in Bulgaria. Resistance to ampicillin and gentamicin were the predominant profiles, although one Salmonella Corvallis isolate produced an ESBL. The ESBL-producing Salmonella Corvallis isolate clustered separately from the susceptible Salmonella Corvallis isolates.     

Detection of specific antibodies against West Nile and Usutu viruses in healthy blood donors in northern Italy, 2010–2011

Neutralizing antibodies against West Nile (WNV) and Usutu (USUV) viruses were measured in 6000 samples collected, between 1 September 2010 and 30 June 2011, from blood donors living in different districts of Emilia-Romagna, northeastern Italy. On the basis of the microneutralization assay (MNTA), 47 (0.78%) subjects were positive for WNV and 14 (0.23%) for USUV. These results were compared with those obtained 2 years ago and suggest an increased circulation of USUV among humans in Emilia-Romagna.     

Detection of human enteroviruses and parechoviruses as part of the national enterovirus surveillance in the Netherlands, 1996–2011

Laboratories of the Dutch Working Group on Clinical Virology have routinely performed enterovirus diagnostics in the Netherlands since the early 1960s, with country-wide coverage. Enterovirus-positive samples are typed for clinical and epidemiological purposes, as well as to document the absence of poliovirus circulation. Human parechoviruses 1 and 2, initially recognized as enteroviruses, and since 2006 also the higher numbered human parechovirus types, have been detected as part of this surveillance. The purpose of this report is to describe the national enterovirus surveillance data from stool specimens collected in the Netherlands between 1996 and 2011 by all the participating laboratories. Since 2007, the average annual percentage of human enterovirus- and parechovirus-positive specimens increased from 6.5 to 10.8 % and from 0.3 to 2.5 % of the total numbers of specimens tested, respectively, following a gradual implementation of molecular diagnostics directly on clinical samples. Increased detection rates were observed for human enterovirus species A coxsackieviruses (from 0.1 to 0.5 %). Human enteroviruses of species B, C, and D were detected at average rates of 4.7, 0.04, and 0.005 %, respectively. The introduction of molecular diagnostics also resulted in an increase in the number of untyped enterovirus-positive specimens for which the presence of poliovirus was not excluded (from 1.3 to 3.1 % since 2007). To increase knowledge on human entero- and parechovirus epidemiology and type-specific pathogenesis, as well as to warrant the quality of the poliovirus surveillance in the Netherlands, it is of importance to continue the typing of enterovirus- and parechovirus-positive samples.