Prevalence of extended-spectrum beta-lactamase-producing Enterobacteriaceae among clinical isolates in Turaif general hospital, northern borders- Saudi Arabia.

INTRODUCTION: Enterobacteriaceae that produce extended-spectrum beta-lactamase (ESBL) are quickly spreading, posing a threat to world healthcare. METHODOLOGY: 138 gram-negative bacteria were collected from different samples (stool, urine, wound, blood, tracheal aspirate, catheter tip, vaginal swab, sputum, and tracheal aspirate) from hospitalized patients. Samples were subcultured and identified in accordance with their biochemical reactions and culture characteristics. Against all the isolated Enterobacteriaceae, an antimicrobial susceptibility test was performed. VITEK®2 system, phenotypic confirmation, and Double-Disk Synergy Test (DDST) had been utilized to identify the ESBLs. RESULTS: Of the 138 samples studied, the prevalence of ESBL-producing infections among the clinical samples of the present study was 26.8 % (n = 37). E. coli was the commonest ESΒL producer at 51.4% (n = 19) followed by K. pneumoniae at 27% (n = 10). The potential risk factors for the ESBL development that produces bacteria were as follows, patients with the presence of indwelling devices, previous history of hospital admission, and usage of antibiotics. ESBL is statistically (p ≤ 0.05) higher among the patients with indwelling devices, ICU admission, who had a previous hospital admission in the last 6 months as well as who was given antibiotics (quinolones and/or cephalosporins) in the last 6 months. One hundred thirty-two (95.7%) of ESBL isolates were resistant to amoxicillin, while the lowest resistance was for fosfomycin (15.2%). CONCLUSIONS: ESBL-producing Enterobacteriaceae are highly prevalent in Turaif General Hospital setting with some potential risk factors. A strict policy to be made available on the usage of antimicrobials in hospitals and clinics should be established.

Immunomodulatory effects of chronic trichinellosis on Toxoplasma gondii RH virulent strain in experimental rats.

Mixed parasitic infections could affect the host immunological responses and re-design the pathogenesis of each other. The impact of Toxoplasma gondii (T. gondii) and Trichinella spiralis (T. spiralis) co-infection on the immune response remains unclear. The objective of the present study was to investigate the possible effect of chronic trichinellosis on the immune response of rats infected with T. gondii virulent RH strain. Animals were divided into four groups: group I: non-infected negative control; group II: infected with T. spiralis; group III: infected with T. gondii and group IV: infected with T. spiralis then infected with T. gondii 35 days post T. spiralis infection (co-infected group). The interaction between T. spiralis and T. gondii was evaluated by histopathological examination of liver and brain tissues, immunohistochemical expression of inducible nitric oxide synthase (iNOS), and ß-catenin in the brain tissues, and CD4+ and CD8+ T cells percentages, and tumor necrosis factor (TNF)-alpha expression in the spleen tissues. Along with, splenic interleukin (IL)-4 and IL-10 mRNA expression levels were measured 15 days post-Toxoplasma infection. Our study revealed that prior infection with T. spiralis leads to attenuation of Th1 response against T. gondii, including iNOS, TNF-α, and CD8+ T-cell response with improvement of the histopathological changes in the tissues. In conclusion, in the co-infected rats, a balanced immune response has been developed with the end result, improvement of the histopathological changes in the liver and brain.

The effects of L-citrulline adjunctive treatment of Toxoplasma gondii RH strain infection in a mouse model.

Toxoplasma gondii is a zoonotic intracellular protozoan parasite and its therapeutic limitations are one of its major problems. L-citrulline is an organic compound that has beneficial effects on many diseases. The purpose of this study was to assess the impact of L-citrulline, alone or in combination with sulfamethoxazole-trimethoprim (SMZ-TMP) on acute toxoplasmosis caused by Toxoplasma gondii RH virulent strain. In our study, 60 Swiss albino mice were divided into two main groups; the control group and the infected treated group, which was subdivided into group IIa: infected treated with L-citrulline, group IIb: infected treated with SMZ-TMP, and group IIc: infected treated with L-citrulline combined with SMZ-TMP. The effects of treatment were assessed by parasitological study, electron microscopic study of tachyzoites, and histopathological study of the liver. Moreover, ELISA measurement of the serum level of Interferon-gamma, Interleukin 10, Nitric oxide, and apoptotic markers was used. It was noticed that L-citrulline combined with SMZ-TMP significantly increased the survival time of infected mice with a significant decrease in the number of tachyzoites compared to the other groups. Moreover, it increased the levels of measured cytokines and serum anti-apoptotic proteins Bcl-2 and improved the extent of liver cell damage associated with a decrease in inflammatory infiltration. In conclusion, L-citrulline supplementation was found to be effective against acute toxoplasmosis, especially when combined with SMZ-TMP as it has multifactorial mechanisms; nitric oxide production, anti-inflammatory, anti-apoptotic, and immune stimulator.

Human umbilical cord blood mesenchymal stem cells as a potential therapy for schistosomal hepatic fibrosis: an experimental study.

The objective of our study was to assess the effect of human umbilical cord blood (HUCB) mesenchymal stem cells (MSCs) transplantation on schistosomal hepatic fibrosis in mice. The study animals were divided into three groups. Group I is a control group, where the mice were infected with Schistosoma mansoni cercariae and remained untreated. The mice of the other two groups were infected and treated with either praziquantel (Group II) or HUCB-MSCs (Group III). Liver function tests, as well as histopathological evaluation of liver fibrosis using hematoxylin and eosin and Masson's trichrome stains, were performed. Additionally, an immunohistochemical study was carried out using anti-glial fibrillary acidic protein (GFAP) in hepatic stellate cells. Compared to the control group, the treated (praziquantel and MSCs) groups showed a substantial improvement, with a significant difference regarding the histopathological evaluation of liver fibrosis in the MSCs-treated group. In conclusion, MSCs could be a promising and efficient cell therapy for liver fibrosis.

The impact of L-citrulline on murine intestinal cell integrity, immune response, and arginine metabolism in the face of Giardia lamblia infection.

Giardiasis is an intestinal protozoal disease caused by Giardia lamblia (G. lamblia) which is a major worldwide health problem due to development of resistance to commonly used drugs. Therefore, it is necessary to identify an effective drug for giardiasis. This study aimed to assess the therapeutic role of L-citrulline against giardiasis in experimental animals. 40 male Swiss Albino weaned rats were used in this study, divided into four groups. Group I: normal control; group II: infected un-treated; group III: infected and treated with L-citrulline and Group IV: infected and treated with metronidazole. The efficacy was evaluated by counting Giardia trophozoites in the intestinal mucosa and cysts in the stool of infected rats. Histopathological analyses, immunohistochemistry expression of inducible nitric oxide synthase (iNOS) in the small intestine tissues were performed. Along with, serum IL6, the intestinal arginase enzyme level and giardial flavohemoglobin (flavoHb) expression were measured. L-citrulline administration reduced the mean number of G. lamblia cysts and trophozoites, serum IL-6, and intestinal arginase enzyme levels. Furthermore, the intestinal brush border was restored, with a reduction in the inflammatory infiltrate and an increase in iNOS activity. Moreover, there was a significant decrease in flavoHb gene expression in both the L-citrulline and metronidazole treated groups. Thus L-citrulline is effective in NO production therefore it has a therapeutic potential in controlling giardiasis.

MRSA as an indicator of infection control measures in Turaif General Hospital, Northern Area-Saudi Arabia.

INTRODUCTION: Saudi Arabia can be considered a hot spot for Methicillin-resistant Staphylococcus aureus (MRSA) infections with significant regional variations. As far as we know, this is the first study to evaluate the prevalence of MRSA in clinical samples obtained from Turaif general hospital (TGH), Northern Area-Saudi Arabia, and screening the resistance profile to the most regularly used antimicrobials as an indicator for evaluation of the implemented infection control measures. METHODOLOGY: Totally, 410 Samples were collected from patients in TGH with clinically suspected nosocomial infections. MRSA isolates were identified by the classical bacteriological, biochemical, and cefoxitin-based methods as recommended by the Clinical Laboratory Standard Institute. Confirmation of isolates and testing of their antimicrobial susceptibilities were performed by the automated Vitek 2 compact system. RESULTS: Totally, 130 nosocomial isolates were detected. Staphylococcus aureus (29.23%) was the most frequently isolated Gram-positive pathogen. MRSA represented 39.47% of Staphylococcus aureus and 11.54% of all isolates. MRSA-causing surgical site infections were the most predominant type of MRSA nosocomial infections representing (25.00%). Recent antibiotic therapy, prolonged hospital stays, and indwelling devices were significant risk factors for the development of MRSA infections. Although all MRSA isolates were sensitive to vancomycin, teicoplanin, linezolid, Fosfomycin, and tigecycline, many isolates were resistant to other tested antimicrobials. CONCLUSIONS: Hospital administrators should strengthen the ideal use of antibiotics according to the local hospital policy to control the selective drug pressure on Staphylococcus aureus strains with minimizing exposure to the risk factors by implementing the proper infection control policies.

Different panel of toll-like receptors expression during chronic Schistosoma mansoni infection in experimental animals.

BACKGROUND: Many studies have reported the immunomodulatory effect of helminths to avoid the lethal immunopathology. During schistosomiasis, the immune response is orchestrated by toll-like receptors (TLRs). Modulating TLRs can alter the function of antigen presentation cells with the shift of the host's Th1 response to a dominant regulatory Th2 response. The objective of our study was to clarify which TLRs are related to the immune response of chronic Schistosoma infection. METHODS: The study animals were divided into two groups; group I: uninfected mice; control group and group II: Schistosoma mansoni infected mice. mRNA expression of TLR2, 3, 4, 7, and 9 in different organs (liver, large intestine, and spleen) were assessed on day 90 post-infection. RESULTS: TLR gene expression has changed depending on the tissue studied as the mRNA level of TLR2, TLR7, and TLR9 were significantly upregulated in all examined organs while TLR3 expression showed only significant upregulation in the liver of infected mice. On the other hand, TLR4 expression was significantly upregulated in the liver while significantly downregulated in the large intestine. CONCLUSION: This study provides a better understanding of TLRs profile in different organs against S. mansoni parasites during the chronic phase of infection.

Age-related changes in cerebral congenital toxoplasmosis: Histopathological and immunohistochemical evaluation.

Congenital toxoplasmosis is a widespread worldwide disease producing varying degrees of damage to the fetus including ocular and neurological impairment. However, the underlying mechanisms are not yet clear. Therefore, the current study aimed to investigate the progress of congenital cerebral toxoplasmosis in experimentally infected offspring animal model at different age groups till become adults. To fulfill this aim, the offspring of Me49 T. gondii infected pregnant mice were divided into groups; embryo, infant, young and adult phases. Blood and brain samples were collected for further hormonal and histopathological studies and immunohistochemical staining of glial fibrillary acidic protein (GFAP) and synaptophysin (SYN). Our results showed several encephalitic changes in the infected groups ranging from gliosis to reduced cortical cell number and fibrinoid degeneration of the brain. We showed increased expression of GFAP and SYN indicating activation of astrocytes and modification of the synaptic function, respectively. These changes started intrauterine following congenital infection and increased progressively afterward. Moreover, infected mice had elevated corticosterone levels. In conclusion, the current study provided new evidences for the cellular changes especially in the infected embryo and highlighted the role of GFAP and SYN that may be used as indicators for T. gondii-related neuropathy.

Can the route of Toxoplasma gondii infection affect the ophthalmic outcomes?

Ocular toxoplasmosis is the most common cause of retinochoroiditis worldwide in humans. Some studies highlighted the idea that ocular lesions differ according to the route of infection but none of them mimicked the natural route. The current study aimed to investigate the ophthalmic outcomes in congenital and oral routes of infection with Toxoplasma in experimental animals. Mice were divided into three groups; group I: congenital infection, group II: acquired oral infection and group III: non-infected. We used Me49 chronic low-virulence T. gondii strain. We found that retina is the most affected part in both modes of infections. However, the retinal changes are different and more pronounced in case of congenital infection. The congenitally infected mice showed retinal lesions e.g. total detachment of retinal pigment epithelium from the photoreceptor layer and irregular arrangement of retinal layers. More severe damage was observed in mice infected early in pregnancy. While the postnatal orally infected mice showed fewer changes. In conclusion, the routes of Toxoplasma infection affect the ophthalmic outcomes and this may be the case in human disease. Although both are vision threatening, it seems that the prognosis of postnatal acquired ocular toxoplasmosis is better than that of congenital disease.

IMPACT OF IMMUNE SUPPRESSION ON HISTOPATHOLOGICAL AND IMMUNOLOGICAL PARAMETERS OF MICE EXPERIMENTALLY INFECTED WITH GIARDIA LAMBLIA.

Giardiasis is one of the most frequent entero-parasites worldwide; its prevalence is more common in developing countries. Giardia lamblia is considered one of the opportunistic parasites and aits clinical manifestations represent the expression of host resistance and parasite viri lence. As of chronic giardiasis cases were expected to worsen in immunosuppressed patients with development of various complications. This work assessed the histolopathological and the possible immunological effects of infection with G. lamblia in an immunosuppressed experimental animal model in comparison to immunocompetent one. Mice were divided into 4 groups;. group I: simmunocompetent (IC) mice infected with G. lamblia cysts, group II: immunosup pressed (S) mice infected with cysts, group III: uninfected immunocompetent mice and group. IV: uninfected immunosuppressed mice. From each group, small intestine was. removed for histopathological and molecular studies. Also, cyst counting in the stool of infected mice was estimated. We found that the number of G. lamblia cysts in the stool of IS mice was significantly higher than that from IC ones. Shortening of the villi was more pronounced in the IS than in IC group. Furthermore, intraepithelial lymphocytic count, goblet cell count and mast cell count were significantly decreased in the IS infected group as compared to IC ones. Expression of interleukin.6 mRNA showed high expression in IC infected mice while it was weak in IS mice. In conclusicn, the present study revealed the importance of the innate immunity presented by goblet cells, mast cells and other adaptive immunity responses; in the clearance of Giardia.

Implication of artemisinin nematocidal activity on experimental trichinellosis: In vitro and in vivo studies.

Benzimidazole drugs are used for treatment of trichinellosis, but they have a limited effect against encapsulated larval stages of Trichinella spiralis. Hence, there is a considerable interest in developing new anthelmintic drugs. Our aim is to investigate the possible effect of artemisinin on T. spiralis in in vitro and in vivo studies. T. spiralis worms were isolated from infected mice and transferred to 3 culture media; group I: with no drugs, group II: contained artemisinin and group III: contained mebendazole, then they were subjected to electron microscopic study. An in vivo study was done where mice were divided into three groups; group I: infected and untreated, group II: received artemisinin and group III: received mebendazole. The efficacy of treatment was assessed by adult and total larval counts, histopathological study of the small intestinal and muscle tissues and immunohistochemical staining of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in muscles. Adult worm teguments showed significant degeneration and destruction with both drugs. Also, significant reduction of total adult and larval counts occurred in treated groups in comparison to the control group. Histopathological examination of the small intestine and muscles showed marked improvement with reduction in the inflammatory infiltrates with both drugs. COX-2 and VEGF expressions were reduced in both treated groups with more reduction in the artemisinin-treated group. This study revealed that artemisinin has the potential to be an alternative drug against trichinellosis.

Nitazoxanide anthelmintic activity against the enteral and parenteral phases of trichinellosis in experimentally infected rats.

Most of the drugs used for the treatment of trichinellosis show a limited bioavailability and a high degree of resistance. Therefore, this study aimed to characterize the anthelmintic potential activity of nitazoxanide (NTZ) in a rat model of experimental trichinellosis. Animals were divided into three groups; group I, infected and non-treated; group II, received NTZ for three days post-infection (dpi) and group III, received NTZ 30 dpi for 14 consecutive days. Treatment efficacy was assessed by Trichinella spiralis adult and larval counts, histopathological studies of the small intestine and muscles and inducible nitric oxide synthase (iNOS) expression in the small intestine. T. spiralis adult count was reduced in NTZ -treated group (66.6%) and the larval count decreased to 68.7 and 76.7% in the early and late treatment, respectively. The infected non-treated rats showed massive inflammatory cellular infiltration in the small intestines and muscles. This inflammatory response was minor in the treated groups and was accompanied by a decrease in iNOS expression. Moreover, in group III, the larvae were replaced by homogenized substance with some destructive changes in the capsule. In conclusion, NTZ showed a promising activity against enteral and more effect in parenteral phases of trichinellosis.

Carbonic anhydrase enzyme as a potential therapeutic target for experimental trichinellosis.

Trichinellosis is a globally distributed helminthic infection. There is a considerable interest in developing new anti-helminthic drugs affecting all the developmental stages of Trichinella. Acetazolamide (carbonic anhydrase (CA) inhibitor) involves a novel mechanism of action by inhibiting such an essential enzyme for parasite metabolism. This work aimed to study the effect of acetazolamide against different stages of T. spiralis in experimental animals. Mice were divided into three groups: group I: infected and treated with acetazolamide on day 2 post infection (P.I.), group II: infected and treated with acetazolamide on day 12 P.I., and group III: infected non-treated. From each group, small intestine and muscles were removed for histopathological and immunohistochemical studies. Also, total adult and muscle larval count were estimated. We found that acetazolamide was effective in reduction of both adult and muscle larval counts. When given early, the effect was more pronounced on the adults (62.7 %). However, the efficacy of the drug against muscle larvae was increased when given late (63 %). Improvement of the intestinal histopathological changes was observed in all the treated groups. Degeneration of encysted larvae with minimal pathologic changes of infected skeletal muscle was observed in the treated groups. Expression of matrix metalloproteinase-9 showed a statistically significant decrease in the intestinal and muscle tissues in all treated groups as compared to the control group. In conclusion, the present study revealed that acetazolamide, carbonic anhydrase inhibitor, could be a promising drug against both adults and larvae of T. spiralis.