Influenza sentinel surveillance in Libya was formally established in 2022 by the Libyan National Center for Disease Control (NCDC). Between 2022 and 2024, a total of 1864 nasopharyngeal specimens were collected from patients presenting with influenza-like illness and tested using the GeneXpert for influenza A virus, influenza B virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and respiratory syncytial virus (RSV). Influenza A virus was detected in 21.1% (393/1864) of samples and influenza B virus was detected in 5.4% of samples (100/1864). SARS-CoV-2 and RSV were identified in 11.6% (216/1864) and 4.1% (77/1864) of specimens, respectively. A subset of 22 influenza A-positive samples was selected based on sample availability and sufficient remaining volume after the initial test for confirmatory testing and further molecular characterization. Real-time RT-PCR subtyping identified 11 A(H1N1)pdm09 and four A(H3N2) viruses. Whole-genome sequencing was successfully performed for 11 isolates, followed by phylogenetic analysis. Genetic characterization revealed that all A(H1N1)pdm09 viruses belonged to clade 6B.1A.5a.2a (5a.2a), while A(H3N2) viruses clustered within clade 3C.2a1b.2a.2a.3a.1 (2a.3a.1) were based on hemagglutinin gene mutations. No neuraminidase mutations associated with antiviral resistance were detected. This study represents the first molecular and phylogenetic characterization of circulating human influenza viruses in Libya, with sequence data submitted to the Global Initiative on Sharing All Influenza Data (GISAID) to establish baseline genetic data for influenza viruses in Libya.

Highly pathogenic avian influenza (HPAI) virus H5N1of clade 2.3.4.4b has emerged as the predominant lineage circulating in poultry flocks worldwide, raising concerns regarding the protective efficacy of currently available commercial vaccines, particularly in domestic ducks, which play an important role in virus maintenance and transmission. Thus, this study evaluated the immunogenicity along with the protective efficacy of four inactivated H5 vaccines against a recently isolated local HPAI-H5N1 (Newvalley-3-H5N1-2024, clade 2.3.4.4b) strain in Pekin ducks in Egypt. A total of 150 seronegative ducks were divided into vaccinated and control groups (10 groups) and vaccinated at 10 days of age. At 31 days of age, the vaccinated and positive control groups were challenged using 106.5 EID50/0.5 mL/duck with the local isolate (Newvalley-3-H5N1-2024) via the oculo-nasal route. The vaccine efficacy was assessed through clinical signs, survival rate, hemagglutination inhibition (HI) antibody titer, tracheal and cloacal viral shedding quantified by real-time RT-PCR, and histopathological examination of trachea, lung, pancreas, and brain tissues. Generally, all ducks vaccinated with the ValleyVac Avian Flu H5 plus and MEFLUVACTM H5 PLUS 8 showed a significantly higher survival rate (100%) at 10 days post-vaccination (DPV) than those in the positive control (66.7% mortality rate). In contrast, ducks exhibited mortality rates ranging from 6.7% in the SERVAC Flu H5N1 group to 13.4% in the Sinder Fluvac group. The ValleyVac Avian Flu H5 plus and MEFLUVAC™ H5 PLUS 8 vaccines induced the highest HI antibody titers at 7, 14, 21, and 28 DPV in both homologous and heterologous AIV antigens, resulting in a significant reduction in viral load among all vaccinated duck groups (p-value < 0.05) comparable to the positive control group. Conversely, the SERVAC Flu H5N1 and Sinder Fluvac vaccines provided partial protection, suboptimal immunogenicity at different time points, and elevated viral shedding. Histopathological findings in ValleyVac Avian Flu H5 plus and MEFLUVAC™ H5 PLUS 8 vaccines exhibited mild tissue alterations following AIV challenge. Marked pathological lesions were observed in the SERVAC Flu H5N1 and Sinder Fluvac vaccinated groups. Among tested vaccines, both ValleyVac Avian Flu H5 plus and MEFLUVACTM H5 PLUS 8 showed the highest level of protective efficacy against the circulating AIV strain compared with other commercial vaccines. This study highlights the need for continuous molecular surveillance, antigenic matching, and regular updating of vaccine seed strains to ensure efficient HPAI control in Egypt.

Abstract Despite intensive vaccination efforts, Chicken Infectious Anemia Virus (CIAV) remains a formidable threat to the Egyptian poultry industry, primarily through the emergence of vaccine-escape variants. While most studies have focused on Northern Egypt, there is a critical knowledge gap regarding the viral landscape in the Southern provinces. This study provides the most extensive surveillance to date, spanning 10 diverse Egyptian governorates with a strategic focus on Upper Egypt (2024–2025). Out of 400 collected samples, TaqMan-based qPCR revealed a high prevalence of 30% (120/400). Five representative isolates were selected for whole-genome sequencing and molecular characterization. The isolates were classified as Genotype II by phylogenetic analysis, showing a notable genetic divergence (85–87% amino acid similarity) from traditional Genotype I vaccine strains. Notably, comprehensive recombination analysis identified isolate PX96998 as a mosaic variant, with breakpoints indicating intra-genotypic recombination between closely related genotype II lineages, highlighting complex evolutionary dynamics in the field. Furthermore, 3D homology modeling of the VP1 protein identified critical structural alterations in functional loop regions, potentially hindering the binding affinity of neutralizing antibodies and facilitating immune evasion. In an experimental setting, the genotype II isolate demonstrated hypervirulence in SPF chickens, causing severe development retardation and extensive atrophy of lymphoid organs (p < 0.0001). Pathognomonic pale, fatty bone marrow with a sharp drop in PCV% to 18 ± 0.58% indicated severe aplastic anemia. By the fifth week after infection, there was a complete humoral collapse with undetectable ELISA titers due to the huge systemic replication revealed by viral load measurement, which peaked in the thymus (9.50 ± 0.25 log₁₀) and bone marrow (9.00 ± 0.22 log₁₀). These results were supported by histopathology, which revealed intranuclear inclusion bodies and systemic lymphocyte depletion. These findings support the highly pathogenic genotype II CIAV’s dominance and aggressive evolution in Egypt. The emergence of recombinant variants with altered structural epitopes underscores the urgent need to replace outdated vaccination plans with genotype-matched immunogens in order to lessen the severe consequences on Egypt’s poultry industry.

Fowl adenoviruses are opportunistic emerging viruses that spread widely in fowls, infecting birds of all ages, including young broiler chicks. This study aims to genotype the current adenovirus strains associated with inclusion body hepatitis hydropericardium syndrome (IBH-HPS) among infected broilers in Upper Egypt and to evaluate their pathogenic features. In 2024, 100 tissue samples were collected across Assiut and Sohag governorates in Upper Egypt for genetic characterization and pathogenicity evaluation. FAdVs were detected in 22% (11/50) of flocks. Typical FAdV lesions of dead embryos were observed after seven days post egg inoculation. Regarding the PCR assay of the hexon gene, only 8 of 30 samples were confirmed positive at 897 bp, yielding a 26.6% positivity rate. The remaining samples were considered negative using established RT-qPCR protocols for other viral pathogens. Partial sequencing of the hexon gene revealed that FAdV isolates (n = 4) clustered within FAdV species-D serotype 2/11, as determined by phylogenetic analysis. The four isolates shared (98-99%) and (94-100%) nucleotide and amino-acid similarities to FAdV-D of Israeli strains (2019-2020) and contemporary Egyptian isolates (2022), respectively, and low genetic divergence (54-81%) in comparison with other documented species. The amino acid sequence alignment and 3D structure indicate that the four immunogenic HVRs are located in the L1 region of the hexon protein, and that the highly conserved 91GQMTT95, a specific region for FAdV-D serotype 2/11, is present. Regarding pathogenicity, the gross and histopathological findings observed clearly demonstrate the systemic pathogenicity of FAdV-2/11 in the infected group, with a final mortality rate of 30% at seven days post-infection (dpi). The FAdV DNA in hepatic tissues and cloacal swabs was confirmed by the PCR method at 3 dpi and 5 dpi. These results emphasize the circulating of FAdV-2/11 species D in Upper Egypt and highlight the significant need for a single inactivated vaccine that effectively targets the relevant FAdV serotypes to achieve broader and more efficient protection.

Background:Avian encephalomyelitis (AE) is an imperative viral disease of avian species worldwide caused by the AE virus (AEV). Aim:This retrospective study aimed to genetically characterize field AEV strains circulating in the local governorates of Egypt and assess their genetic divergence in comparison with commercially available vaccines. To the best of our knowledge, this is the first described study of AEV-VP1 gene sequencing and phylogeny in broilers in Egypt. Methods:A total of 150 tissue specimens from broilers of four Egyptian governorates were used for isolation and genetic characterization. The samples were tested for other pathogens, including egg drop syndrome virus, Newcastle disease virus, avian reovirus, avian reticuloendotheliosis virus, infectious bronchitis virus, Chicken anemia virus, and Marek's disease virus. Results:Young chicks showed neurological symptoms and a mortality rate of 4%-8%. Only crop impaction and distended proventriculus were observed in sick chicks. Histopathological findings revealed typical lesions of lymphocytic encephalomyelitis in the cerebrum with mononuclear cuffing of perivascular spaces in the cortex and medulla. The proventriculus revealed mild lymphocytic infiltration within the submucosa. Typical pathological changes in leg rigidity and encephalomalacia were observed in specific pathogen-free embryonated chicken eggs (SPF-ECE). Regarding reverse transcriptase quantitative polymerase chain reaction (RT-qPCR), 8 (8/150) samples were positive with a prevalence rate of 5.3%, and the screening results were negative for other viral infections. The 4 selected positive samples were amplified using a one-step conventional RT-PCR assay for partial sequencing of the AEV-VP1 gene. Interestingly, the phylogenetic analysis exhibited that AEV isolates belong to cluster II within the same clade of Chinese strains and have a genetic similarity to Chinese, Iranian, American vaccinal, and British isolates, with 94%-98%a nucleotide similarity, and 96%-99% amino acid identity. Conclusion:Continuous monitoring and potentially updating the vaccination strategies in a timely manner are necessary to ensure vaccine effectiveness as an efficient control strategy in poultry flocks.

Background and Aim:Newcastle disease virus (NDV) is one of the most economically important avian pathogens worldwide, yet information regarding its molecular epidemiology and pathological characteristics in ostriches remains limited. This study investigated the prevalence, molecular characteristics, pathotype, phylogenetic relationships, and histopathological changes associated with NDV circulating in young ostrich flocks in Egypt. Materials and Methods:A total of 60 tissue samples were collected from diseased, non-vaccinated ostriches aged 3 weeks to 2 months from eight farms across four Egyptian governorates during 2024. Virus isolation was performed using specific-pathogen-free embryonated chicken eggs, followed by hemagglutination and hemagglutination inhibition assays. Pathogenicity was determined using the mean death time (MDT) and intracerebral pathogenicity index (ICPI). Molecular detection was conducted by real-time reverse-transcription polymerase chain reaction targeting the matrix gene, followed by partial fusion gene amplification, sequencing, and phylogenetic analysis. Histopathological examination was performed on major organs, and positive samples were additionally screened for avian influenza virus, infectious bronchitis virus, and infectious bursal disease virus to exclude coinfections. Results:Eight of 60 samples tested positive for NDV, with the highest prevalence detected in Ismailia governorate. All positive samples were negative for the tested coinfecting viruses. The isolates exhibited a hemagglutination titer of 9 log₂ hemagglutination units/mL and a hemagglutination inhibition titer of 6 log₂. Biological pathotyping confirmed a lentogenic pathotype with an MDT of 96 h and an ICPI of 0.4. Phylogenetic analysis classified the isolates within genotype II, class II, possessing the characteristic lentogenic fusion protein cleavage motif ¹¹²GRQGRL¹¹⁷. The isolates shared 97%-99% nucleotide identity with commonly used vaccine strains, including LaSota, Hitchner, and Clone 30. Histopathological examination revealed marked lesions in the respiratory and digestive systems, including epithelial degeneration, hemorrhage, inflammatory infiltrates, lymphoid depletion, hepatic necrosis, and intestinal villous damage, despite the lentogenic nature of the virus. Conclusion:This study provides the first comprehensive molecular, pathotyping, phylogenetic, and histopathological characterization of lentogenic genotype II NDV circulating in young ostriches in Egypt. The findings demonstrate that lentogenic vaccine-related genotype II strains can induce clinically relevant pathological alterations in ostriches, emphasizing the need for continuous molecular surveillance, host-specific vaccination strategies, enhanced biosecurity, and integrated monitoring of ostriches, poultry, and wild birds to reduce NDV transmission and evolution.

Background: Hypericum triquetrifolium (HT) is an herbal medicine that has promising pharmacological properties and is traditionally used to treat multiple diseases. Aim: This study examined the chemical composition, antioxidant, anti-inflammatory, and antiviral properties of HT, focusing on its impact on the cytopathic effect of human coronavirus-229E (HCoV-229E). Methods: The phytochemical content and in vitro bioactivity of the aqueous extract of HT collected from Al Marj, Libya, were documented. Common antioxidants were quantified, and the antioxidant activity of the extract was assessed using standard methods. The anti-inflammatory effect of albumin denaturation was evaluated. In this study, we determined the cytotoxicity on Medical Research Council-5 cells and antiviral activity by measuring the extract's ability to inhibit the cytopathic effect of HCoV-229E on MRC-5 cells. Results: The phytochemical analysis confirmed the presence of phenols, flavonoids, proanthocyanidin, anthocyanidin, and catechin, and a high total phenolic content. The extract possessed strong free radical scavenging activity. In addition, the HT extract significantly inhibited heat-induced albumin denaturation, demonstrating its anti-inflammatory effect. The extract significantly inhibited the cytopathic effect of HCoV-229E on MRC-5 cells, indicating for the first time the antiviral effect of HT. Conclusion: To the best of our knowledge, this study is the first to demonstrate that HT extract has low cytotoxicity and potential antiviral activity against a surrogate human coronavirus. Although these results are promising, they are based on in vitro testing with HCoV-229E, and further studies, including in vivo and clinical investigations, are necessary to assess the relevance of HCoV-2 to severe acute respiratory syndrome-CoV-2 and other human coronaviruses. [J Microbiol Infect Dis 2026; 16(1.000): 1-11]

Avian oncogenic viruses represent a major cause of neoplastic and immunosuppressive diseases in poultry, leading to substantial economic losses worldwide and providing valuable models for studying virus-induced tumorigenesis. Among these viruses, Marek's disease virus, avian leukosis virus, and reticuloendotheliosis virus induce lymphoid and hematopoietic malignancies through distinct yet convergent molecular mechanisms. Increasing evidence indicates that microRNAs and their viral homologs are central regulators linking viral infection to oncogenic transformation, immune dysregulation, and pathological outcomes. This review provides an integrated overview of microRNA's role in the pathogenesis and pathology of avian oncogenic viral diseases, emphasizing its contributions to lymphocyte proliferation, survival, immune modulation, and tumor development. We discuss the unique case of Marek's disease virus, in which a viral microRNA ortholog is indispensable for tumor induction in vivo, representing the first direct demonstration of a virus-encoded microRNA acting as a primary oncogenic factor in a natural host. In contrast, avian leukosis virus and reticuloendotheliosis virus exploit host microRNA pathways through insertional mutagenesis and NF-κB-mediated transcriptional activation, respectively, contributing to tumor progression in a context-dependent manner. The review further correlates molecular findings with gross and microscopic pathological lesions. It highlights how microRNA-driven regulatory networks shape disease severity, tissue tropism, and tumor morphology. So, these insights establish microRNA as a conserved molecular hub in avian viral oncogenesis and underscore its relevance for understanding viral tumor pathology, improving differential diagnosis, and advancing comparative oncology across species.

Background: Newcastle disease (ND) is a highly infectious disease affecting multiple avian species worldwide. Repeated ND outbreaks in Pakistan have presented substantial challenges to the poultry sector. Aim: Extensive surveillance in Pakistan over a decade has revealed a high prevalence of avian orthoavulavirus 1 (AOAV-1), highlighting the need for tailored vaccination approaches and continuous monitoring. Methods: This study presented a 10-year biosurveillance (2011-2020) of AOAV-1 across 1083 locations (including commercial farms, backyard poultry, live bird retail stalls, household birds, national zoos, and wild migratory birds), with a total of 5,145 samples (trachea and oropharyngeal swabs) and 822 blood samples collected from 18 avian species. Tracheal and swab samples were inoculated in embryonated chicken eggs, and the positive allantoic fluids were assessed for AOAV-1 prevalence using reverse-transcriptase real-time PCR (rRT-PCR) targeting the fusion (F) gene. Serum samples were evaluated using a hemagglutination inhibition (HI) test to detect AOAV-1 antibodies. Results: rRT-PCR analysis showed a prevalence of 37.41%, while seroprevalence assessed through the HI assay was 48%. Moreover, over a decade after repeated outbreaks of virulent AOAV-1 that resulted in high morbidity and mortality in Pakistan, the responsible strain was detected in vaccinated chickens across multiple commercial poultry farms, despite the existence of elevated AOAV-1-specific antibody titers (>4.6 log2). Conclusion: The observations suggest a possible role of vaccinated poultry as a reservoir of virulent AOAV-1. These findings contribute to our understanding of the high prevalence of AOAV-1 in Pakistan, emphasizing the need for customized vaccination approaches and continuous monitoring to enable effective management of AOAV-1 in avian species.

Background: Infectious bronchitis virus (IBV) is a highly spreading, evolving virus that induces multiple manifestations, including respiratory, urinary, and reproductive symptoms, and presents a considerable risk to the Egyptian poultry sector. This study assessed various IBV vaccination protocols available in broiler populations comprising live attenuated vaccines such as IB Var II, 793/B (4/91), IB Primer, and H120 against the local novel IBV-GI-23.3 strain. Methods: Vaccines were administered to eight groups of SPF chicks at 1 day only or 1 + 14 days of age. Birds were challenged via the oculo-nasal route at 28 days of age using 106 EID50/0.2 mL/chick with the NewValley-1-EGYIBV-GI23.3-2023 local strain. Ciliostasis activity and the scores for histopathological lesions were evaluated at 7 days post-challenge (DPC). Virus shedding was monitored at 3, 5, and 7 DPC using the real-time RT-PCR method. Results: The ciliostasis test indicated that the vaccinated groups receiving the IB Primer + 4/91 vaccine regime at 1 day only or 1 + 14 days of age received the highest level of protection (65%, 68%, respectively). Similarly, administration of IB Primer + IB Var II at 1 + 14 days of age demonstrated substantial protection (63%). Conversely, administering the H120 + 4/91 vaccination protocol at days 1 and 14 resulted in a moderate level of protection (53%). Tracheal IBV shedding quantification and subsequent histopathological signs of trachea, proventriculus, bursa, and kidney degenerative changes were significantly lower in the vaccinated groups (especially the IB Primer + 4/91 vaccine regime at 1 day only or 1 + 14 days) than in the positive control groups. Conclusions: The heterologous combined IB Primer + 4/91 program demonstrated the most significant protective efficacy against the IBV field challenge strains compared with other vaccines in broiler chickens.

The bioactive algal components that contribute to their antimicrobial properties have garnered significant attention, particularly in light of the rising incidence of antibiotic resistance. The current study aimed to evaluate the antibacterial activity of a Petalonia fascia methanolic extract and to explore the potentiation action of extract-antibiotic combinations with the available antibiotics, as well as the effects of their mixture on multidrug-resistant (MDR) bacteria, namely, five methicillin-resistant Staphylococcus aureus (MRSA) strains. The algal crude extract displayed antibacterial activity against all assayed isolates, with an inhibition zone ranging from 16 to 21 mm and the best spectrum of bactericidal effect with a ratio of MBC/MIC < 4 obtained on the five tested bacterial strains. Amoxicillin-extract mixtures decreased the bacterial growth rate dramatically on all five S. aureus isolates in a time-dependent manner. These results indicate the ability of the extract to modulate antibiotic activity. However, the possibility of its use to solve the issue of antibiotic-resistant bacterial strains and their application as therapeutic agents against infectious diseases warrants further investigation.

The Libyan coast has various types of wetlands that are passed by many migratory birds throughout the year, however, studies on bacterial isolation from these birds in Lybia are scarce. The present study aimed to isolate enteropathogenic bacterial species from the seagulls that migrated to the Libyan coast as well as identification of the antibiotics that are resistant to these bacteria. A total of 50 fresh fecal samples were collected from slender-billed gulls in January 2023 at Farwa Island near the city of Zuwara, in Western Libya. Bacteria were isolated by conventional culturing method, identified using the Enterosystem 18R, and antibiotic susceptibility tests were conducted on the isolated bacteria. The results revealed the isolation of 46 bacteria, but only 32 of them were identified using biochemical tests. These identified bacteria belong to six species of Enterobacteriacae, namely Citrobacter (C.) freundii, Pantoea (P.) agglomerans, Escherichia (E.) coli, Enterobacter (En.) cloacae, Serratia liquifaciens, and Proteus mirabilis, with percentages of 53.125%, 31.25%, 6.25%, 3.125%, 3.125%, and 3.125%, respectively. All isolated bacteria were 100% sensitive to gentamicin (10 µg) and ciprofloxacin (5 µg). The highest resistance result was observed against the antibiotic cefoxitin (30 µg), with both C. freundii (5 samples) and P. agglomerans (4 samples). Resistance was observed in 5 samples of C. freundii and 4 samples of P. agglomerans out of 11 samples. Resistance to antibiotics, such as azithromycin (15 µg), ceftriaxone (30 µg), and ampicillin (10 µg), was also noted in a few isolates. The results indicated that C. freundii was the most antibiotic-resistant bacterial species isolated in this study. The highest multiple antibiotic resistance index was demonstrated by bacteria C. freundii, P. agglomerans, and En. cloacae, with a value of 0.33 for each of them. In conclusion, slender-billed gulls carry multi-drug-resistant bacteria. The study recommends the implementation of a national program to survey antibiotic-resistant bacteria, determine their prevalence, and assess the presence of antibiotic residues in animal-derived food. Furthermore, the present study advises expanding scientific studies on risk analysis, and antibiotic alternatives in migratory birds.

Background: Food poisoning caused by bacterial agents is a worldwide problem, usually accompanied by unpleasant symptoms and may be sever leading to death. Natural compounds from marine algae namely flavonoids may play a role in the remedy of this condition. Aim: This research aims to assess the potency of flavonoids extracted from Enteromorpha intestinalis and Caulerpa prolifera as antibacterial agents. Methods: E. intestinalis was collected from Western Libyan Coast and C. prolifera was collected from Farwa Island. The antimicrobial activity and determination of minimum inhibitory concentration of algal flavonoid containing extracts was performed in vitro against some positive and negative Gram bacteria. Results: Crude extract containing flavonoids from E. intestinalis were more effective than C. prolifera extract against Staphylococcus aureus with antimicrobial essay (25-28+1 and 14.5-37.5+0.5-1.5), MIC (50 and 50-250 µg/mL), MBC (75 and 75-250 µg/mL). In Bacillus cereus, the antimicrobial assay (19-24.5+0.5-1.5: 24+1), MIC (50-250 + 100 µg/mL) and MBC (250 and 125 µg/mL). On the other hand, flavonoids containing extract from C. prolifera were more effective than E. intestinalis against Enterohemorrhagic Escherichia coli O157 EHEC O157 (25-28+1: 14-18.5+0.5-1.5), MIC (100-250:100-500 µg/mL) and MBC (150-250 and 250-500 µg/mL). Salmonella enterica qualitatively combat by flavonoid from E. intestinalis (13.5-14+0.5-1: 10.5-13.5+0.5-1.5), MIC (100-250: 250 µg/mL) and MBC (100-250: 250 µg/mL). Flavonoids from C. prolifera (4 strains: 2 strains) were effective against S. enterica. Crude flavonoids from both algae were not effective against Bacillus pumilus. Conclusion: Data from this study could conclude that flavonoid extracts from E. intestinalis and C. prolifera could be used against foodborne bacterial agents.

Background: Fowlpox virus (FPV) has been used as a vector for many years. To date, surprisingly, very little data exist on the persistence of fowlpox vaccines in chicken tissues, or what kind of immune cells respond to vaccination at the site of inoculation. Although both humoral and cellular- mediated immunity (CMI) play a part in overall immunity against FPV, little is known regarding the cell-mediated immune responses to FPV infection. Aim: The main aim of this paper was to measure persistence of fowlpox vaccine in skin tissues following vaccination. Methods: One-day-old chicks were vaccinated with Fowlpox virus FP9. Skin samples were collected from the site of inoculation for several days following vaccination to assess the presence of for FPV, as well as other immune cells including macrophages, CD4+ T cells, CD8+ T cells, and B cells. Results: Results showed that FPV does not persist for long, and is cleared by 6 days post-vaccination (dpv). The response of immune cells (macrophages, B cells, CD4+ and CD8+ T cells) that infiltrated the site of vaccination was assessed. Conclusion: The results in this paper reflected the response at the site of inoculation following single vaccination, therefore, further studies regarding viral persistence and infiltration of immune cells at the site of inoculation after booster vaccination should be done. [J Microbiol Infect Dis 2024; 14(3.000): 131-140]

Background and Aim: Bovine viral diarrhea (BVD) is endemic in North Africa and the Mediterranean Basin with high socioeconomic impacts. However, there are no data on this disease in Libya. One of the aims of this study was to provide data on BVD in Libya, to fill in the gap in the region and to investigate the level of seroprevalence of BVD virus (BVDV) in Libya and associated risk factors. Material and Methods: A total of 1599 serum samples were collected from cattle herds belonging to seven Libyan regions. All sera were assayed using a screening enzyme -linked immunosorbent assay for the detection of antibodies against BVDV. Results: The overall seroprevalence of BVDV was estimated to be 48.6% (95% confidence interval, 46.08%-50.98%). A seroprevalence rate of 36.8% was detected in cattle aged <1 year, 41.0% in cattle aged between 1 and 2 years, and 49.7% in cattle aged >2 years. Statistically significant differences (p = 0.001) were observed between age groups. BVDV seroprevalence was significantly associated with geographical region (p = 0.033). Conclusion: To the best of our knowledge, this is the first study on BVD in Libya, and the results suggest that BVD is endemic in Libya. Further studies are required to isolate and characterize the circulated BVDV in Libya.

Background and Aim:Klebsiella pneumoniae is one of the most common causes of clinical and asymptomatic mastitis in dairy cattle, as well as in milk and dairy products that affect milk quality. Mastitis caused by K. pneumoniae is even more serious due to its poor response to antibiotic therapy. The aim of this study was to detect and identify the presence of K. pneumoniae in milk and dairy products produced in Libya. Materials and Methods:A total of 234 samples were randomly collected from various locations in Libya. Samples were examined for the presence of K. pneumoniae using conventional cultural techniques, including cultivation in violet red bile agar plus 4-methylumbelliferyl-ß-D-glucuronide broth and CHROM agar, followed by polymerase chain reaction identification and partial sequencing of 16S rRNA. Results:Of the 234 samples of milk and dairy products collected, 16 (6.8%) isolates revealed mucoid colonies on agar media that were phenotypically suggested to be K. pneumoniae. Identification of isolates was confirmed using molecular techniques (16S rRNA). Among the examined samples, K. pneumoniae was recovered from camel's milk, raw cow's milk, raw fermented milk, Maasora cheese, Ricotta cheese, soft cheese, full cream milk powder, milk powder infant formula, cereal baby food, and growing-up formula. Antibiotic susceptibility testing was performed on 12 of the 16 K. pneumoniae isolates, and the results showed that K. pneumoniae isolates were resistant to more than eight antibiotics; interestingly, two isolates showed metallo-beta-lactamase (MBL) production. Conclusion:K. pneumoniae is considered a risk to human health because many of these products do not comply with the microbiological criteria of international and/or Libyan standards. This study emphasized the relationship between K. pneumoniae and raw milk, cheese, milk powder, and infant milk retailed in Libya. There is a need to take the necessary measures to ensure effective hygiene practices during production in dairy factories, handling, and distribution on the market, in particular at a small local production scale.

Fowlpox virus (FPV) has been used as a vector for many years. To date, surprisingly, very little data exist on the persistence of fowlpox vaccines in chicken tissues, or what kind of immune cells respond to the vaccination at the site of inoculation. Although both humoral and cellular mediated immunity (CMI) play a part in overall immunity against FPV, little is known regarding the cell-mediated immune responses to FPV infection. The main aim of this paper was to measure persistence of the recombinant fowlpox vaccine in the skin tissues following vaccination. The results showed that the recombinant FPVs do not persist for long, and are cleared by 6 days post-vaccination (dpv). The response of immune cells (macrophages, B cells, CD4+ and CD8+ T cells) that infiltrating the site of vaccination was estimated.

West Nile virus (WNV) is a globally significant mosquito-borne Flavivirus that causes West Nile disease (WND). In Libya, evidence of WNV circulation has been reported in humans but never in animals. The aim of this study was to determine the seroprevalence of WNV infection in horses and dogs in Libya. In total, 574 and 63 serum samples were collected from apparently healthy, unvaccinated horses and dogs, respectively, between 2016 and 2019. A commercially available competitive enzyme-linked immunosorbent assay (c-ELISA) kit was initially used to test the collected samples for the presence of WNV Ig-G antibodies. Positive and doubtful sera were also tested using a more specific virus neutralisation assay to confirm whether the ELISA-positive results were due to WNV or other Flavivirus antibodies. The seroprevalence of WNV IgG antibodies according to ELISA was 13.2% out of 574 of total horses’ samples and 30.2% out of 63 of total dogs’ samples. The virus neutralisation test (VNT) confirmed that 10.8% (62/574) and 27% (17/63) were positive for WNV-neutralising titres ranging from 1:10 to 1:640. Univariable analysis using chi-square tests was conducted to measure the statistical significance of the association between the hypothesized risk factors including city, sex, breed, and age group and were then analyzed using the subsequent multivariable logistic regression model for horse samples. Age group was found to be the only significant risk factor in this study. The results of the present study provide new evidence about WNV circulation in Libya.

Background:Libyan wetlands are diverse; the coastline of Libya, in particular, has different kinds of wetlands, such as salt marshes, bays, lakes, lagoons, and islands. These varieties in habitats provide good shelters and foraging sites for migratory birds during their journeys between Eurasia and Africa. Since the beginning of the Libyan winter census of waterbirds International waterbirds census (Libya IWC) in 2005, which continued regularly until 2012, it has had relatively the same performance in the number of covered sites. However, since 2013, due to the security situation that Libya has experienced due to wars and conflict, which negatively affected the quality of the IWC in Libya, the number of sites has dramatically decreased, reaching only six locations during the middle of the previous decade.Aim:The IWC 2022 aimed to count the birds along the Libyan coast from January 10 to 29.Methods:The census activities were conducted from dawn to dusk during the study period by using high-quality Telescopes, binoculars, and digital cameras for the documentation. Point transects method was used to cover the sites.Results:The results of this year showed that a total of 64 sites were covered, and 68 species of waterbirds were counted, with an abundance of 61,850 individuals. During the census period, a total of 52 non-waterbird species found in Wetlands were recorded, and the number of individuals was 14,836 birds. A total of 18 threatened species were observed during this survey, 12 of them are mentioned in the International Union for Conservation of Nature Red List, and nine species are mentioned in the regional activities center of specially protected areas annex II as threatened in the Mediterranean, where the species; Larus audouinii (Payraudeau, 1826), Larus genei (Breme, 1839), and Puffinus yelkouan (Acerbi, 1827) are mentioned in both of them.Conclusion:The lack of the number of ornithologists and bird watchers is still one of the factors affecting the quality of the IWC in Libya, as well as lack of funding remains an important factor that plays a major role in the success of the waterbirds census.

In mammals, the role of interleukin-18 (IL-18) in the immune response is to drive inflammatory and, normally therefore, anti-viral responses. IL-18 also shows promise as a vaccine adjuvant in mammals. Chicken IL-18 (chIL-18) has been cloned. The aim of this study was to investigate the potential of chIL-18 to act as a vaccine adjuvant in the context of a live recombinant Fowlpox virus vaccine (fpIBD1) against Infectious bursal disease virus (IBDV). fpIBD1 protects against mortality, but not against damage to the bursa of Fabricius caused by IBDV infection. The Fowlpox virus genome itself contains several candidate immunomodulatory genes, including potential IL-18 binding proteins (IL-18bp). We knocked out (Δ) the potential IL-18bp genes in fpIBD1 and inserted (::) the cDNA encoding chIL-18 into fpIBD1 in the non-essential ORF030, generating five new viral constructs –fpIBD1::chIL-18, fpIBD1ΔORF073, fpIBD1ΔORF073::chIL-18, fpIBD1ΔORF214, and fpIBD1ΔORF214::chIL-18. The subsequent protection from challenge with virulent IBDV, as measured by viral load and bursal damage, given by these altered fpIBD1 strains, was compared to that given by the original fpIBD1. Complete protection was provided following challenge with IBDV in chicken groups vaccinated with either fpIBDIΔ073::IL-18 or fpIBD1Δ214::IL-18, as no bursal damage nor IBDV was detected in the bursae of the birds. The results show that chIL-18 can act as an effective vaccine adjuvant by improving the fpIBD1 vaccine and providing complete protection against IBDV challenge.