Antimicrobial resistance is a serious threat to public health that dramatically undermines our ability to treat bacterial infections. Microorganisms exhibit resistance to different drug classes by acquiring resistance determinants through multiple mechanisms including horizontal gene transfer. The presence of drug resistance genotypes is mostly associated with corresponding phenotypic resistance against the particular antibiotic. However, bacterial communities harbouring silent antimicrobial resistance genes—genes whose presence is not associated with a corresponding resistant phenotype do exist. Under suitable conditions, the expression pattern of such genes often revert and regain resistance and could potentially lead to therapeutic failure. We often miss the presence of silent genes, since the current experimental paradigms are focused on resistant strains. Therefore, the knowledge on the prevalence, importance and mechanism of silent antibiotic resistance genes in bacterial pathogens are very limited. Silent genes, therefore, provide an additional level of complexity in the war against drug‐resistant bacteria, reminding us that not only phenotypically resistant strains but also susceptible strains should be carefully investigated. In this review, we discuss the presence of silent antimicrobial resistance genes in bacteria, their relevance and their importance in public health.

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‘To be, or not to be’—The dilemma of ‘silent’ antimicrobial resistance genes in bacteria

Background: Infections due to the hepatitis B (HBV) and hepatitis C (HCV) viruses constitute a global public health problem. Although screening of these infections remains a pivotal tool for timely detection and management of carriers, this preventive measure has been neglected in Africa. Objective: The current study determined the prevalence of hepatitis B surface antigen (HBsAg) and anti-HCV as well as their risk factors through a screening campaign organized in a rural setting in northern Cameroon. Methods: A cross-sectional analytical study was conducted during a screening campaign for viral hepatitis organized at the Mokolo District Hospital, Cameroon, from January 19, 2017 to February 27, 2017. Sociodemographic data from all consenting participants was collected and examined for signs of chronic liver disease. Participants were then screened for HBsAg and anti-HCV using a rapid diagnostic test (ACON®). Results: Of the 364 participants enrolled, 28.6% tested positive for HBsAg and 2.2% for anti-HCV. All HBsAg-positive and anti-HCV-positive individuals were asymptomatic and unaware of their infection status prior to testing. None of the socio-demographic factors assessed was associated with a positive HbsAg status. Conclusion: HBV and HCV infections are endemic in this rural health district. Participants who tested positive were apparently healthy and completely unaware of their infection status. Transmission of the hepatitis virus may be a public health concern in this district. It is recommended that community health education activities on preventive measures for HBV and HCV infections, regular screening for disease surveillance, and close follow-up of disease progression in these asymptomatic individuals be conducted.

http://www.jhpr.ir/article_60715_291ab42236eeb7e3c3765b86faec65b0.pdf

Seroprevalence of Hepatitis B and C Infections in Mokolo District Hospital, Northern Cameroon: The Value of a Screening Campaign

Viral and bacterial infections represent an occupational risk for female sex workers. This study aimed at determining HPV coinfection with genital pathogens among female sex workers in West and Central Africa and identifying antibiotic resistance genes. A total of 182 samples from female sex workers were analyzed by real-time PCR and classic PCR. For the molecular diagnosis of HPV, the real-time multiplex amplification kit “HPV Genotypes 14 Real-TM Quant” from SACACE Biotechnologies®, detecting 14 high-risk HPV genotypes, was used, while for other pathogens, the real-time multiplex amplification kit N. gonorrhoeae/C. trachomatis/M. genitalium/T. vaginalis Real-TM, allowing their simultaneous detection, was used. The women were aged 17–50 years with an average age of 27.12 ± 6.09 years. The pathogens identified were HPV 54.94% (100/120), Neisseria gonorrhoeae (13.74%), Chlamydia trachomatis (11.54%) and Mycoplasma genitalium (11.54%). The most common HPV genotypes were HPV68, HPV38 and HPV52. The antibiotic resistance genes identified were bla QNR B 24.00%, bla GES 22.00%, bla SHV 17.00%, blaCTX-M 13.00% and bla QNR S 1.00%. This study revealed the presence of various HPV genotypes associated with other pathogens with problems of antibiotic resistance among sex workers of West and Central African origin working in Ouagadougou.

Molecular Epidemiology of Human Papillomaviruses, Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium among Female Sex Workers in Burkina Faso: Prevalence, Coinfections and Drug Resistance Genes.

This study investigated genotypic and phenotypic antimicrobial resistance profiles, phylogenic relatedness, plasmid and virulence composition of 39 Salmonella enterica strains isolated from chicken meat samples using whole genome sequencing (WGS) technology. Four distinct serotypes were identified; Salmonella Minnesota (16/39, 41%), Salmonella Infantis (13/39, 33.3%), Salmonella Enteritidis (9/39, 23.1%), and one isolate was detected for Salmonella Kentucky (1/39, 2.6%), with sequence types (STs) as followed: ST548, ST32, ST11, and ST198, respectively. Phenotypic resistance to tetracycline (91.2%), ampicillin (82.4%), sulfisoxazole (64.7%), and nalidixic acid (61.6%) was the most observed. Resistome analysis revealed the presence of resistance genes to aminoglycosides, β-lactamase, sulfonamides, trimethoprim, phenicol, lincosamide, macrolides, and tetracyclines. Plasmidome showed the presence of eight incompatibility groups, including IncA/C2, IncFIB(K)_1_Kpn3, Col440I_1, IncR, IncX1, IncI1_1_Alpha, IncFIB(S)/IncFII(S), IncHI2/IncHI2A, IncX2 and ColpVC plasmids across the 39 genomes. Three resistance genes, sul2, tetA and blaCMY-2, were predicted to be located on IncA/C2 plasmid in S. Minnesota isolates, whereas all S. Infantis isolates were positive to IncFIB(K)_1_Kpn3 plasmid that carries blaCTX-M-65 gene. Eleven Salmonella pathogenicity islands and up to 131 stress and/or virulence genes were identified in the evaluated genomes. Phylogenetic analysis showed four phylogroups that were consistent with the identified ST profiles with a high level of inter-diversity between isolates. This is the first genomic characterization of Salmonella isolates from retail chicken meat in Saudi Arabia using WGS technology. The availability of Salmonella genomes from multiple geographic locations, including Saudi Arabia, would be highly beneficial in future source-tracking, especially during epidemiological surveillance and outbreak investigations.

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Antimicrobial resistance and genomic characterization of Salmonella enterica isolates from chicken meat

The emergence of antibiotic-resistant bacteria due to the overuse or inappropriate use of antibiotics has become a significant public health concern. The agri-food chain, which serves as a vital link between the environment, food, and human, contributes to the large-scale dissemination of antibiotic resistance, posing a concern to both food safety and human health. Identification and evaluation of antibiotic resistance of foodborne bacteria is a crucial priority to avoid antibiotic abuse and ensure food safety. However, the conventional approach for detecting antibiotic resistance heavily relies on culture-based methods, which are laborious and time-consuming. Therefore, there is an urgent need to develop accurate and rapid tools for diagnosing antibiotic resistance in foodborne pathogens. This review aims to provide an overview of the mechanisms of antibiotic resistance at both phenotypic and genetic levels, with a focus on identifying potential biomarkers for diagnosing antibiotic resistance in foodborne pathogens. Furthermore, an overview of advances in the strategies based on the potential biomarkers (antibiotic resistance genes, antibiotic resistance-associated mutations, antibiotic resistance phenotypes) for antibiotic resistance analysis of foodborne pathogens is systematically exhibited. This work aims to provide guidance for the advancement of efficient and accurate diagnostic techniques for antibiotic resistance analysis in the food industry.

Antibiotic resistance mechanism and diagnosis of common foodborne pathogens based on genotypic and phenotypic biomarkers.

One of the crucial public health problems today is the emerging and re-emerging of multidrug-resistant (MDR) bacteria coupled with a decline in the development of new antimicrobials. Non-typhoidal Salmonella (NTS) is classified among the MDR pathogens of international concern. To predict their MDR potentials, 23 assembled genomes of NTS from live cattle (n = 1), beef carcass (n = 19), butchers’ hands (n = 1) and beef processing environments (n = 2) isolated from 830 wet swabs at the Yaounde abattoir between December 2014 and November 2015 were explored using whole-genome sequencing. Phenotypically, while 22% (n = 5) of Salmonella isolates were streptomycin-resistant, 13% (n = 3) were MDR. Genotypically, all the Salmonella isolates possessed high MDR potentials against several classes of antibiotics including critically important drugs (carbapenems, third-generation cephalosporin and fluoroquinolone). Moreover, >31% of NTS exhibited resistance potentials to polymyxin, considered as the last resort drug. Additionally, ≤80% of isolates harbored “silent resistant genes” as a potential reservoir of drug resistance. Our isolates showed a high degree of pathogenicity and possessed key virulence factors to establish infection even in humans. Whole-genome sequencing unveiled both broader antimicrobial resistance (AMR) profiles and inference of pathogen characteristics. This study calls for the prudent use of antibiotics and constant monitoring of AMR of NTS.

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Detection of Antimicrobial Resistance, Pathogenicity, and Virulence Potentials of Non-Typhoidal Salmonella Isolates at the Yaounde Abattoir Using Whole-Genome Sequencing Technique

Introduction Les infections sexuellement transmissibles sevissent toujours dans les pays en voie de developpement et particulierement au Cameroun. Le but de notre etude est de determiner la distribution des infections sexuellement transmissibles suivantes: l’hepatite virale B, le Chlamydia trachomatis et de la syphilis dans une population de femmes venant consulter spontanement a l’Hopital de District de Nkoldongo a Yaounde, d’evaluer d’eventuelles coinfections entre ces trois affections et de ressortir les connaissances de ces femmes sur leur mode de transmission sexuelle. Methodes Notre etude prospective et descriptive a porte sur 182 femmes dont l’âge variait entre 18 et 48 ans. Les femmes ont ete testees serologiquement pour le Chlamydia trachomatis par une methode ELISA (kit des laboratoires General Biological Corp). L’hepatite virale B a ete depistee par une methode immunochromatographique (kit des laboratoires Human) et la syphilis par une methode d’agglutination en ce qui concerne le RPR (Kit des laboratoires Biocentric) et le TPHA (kit des laboratoires Human). Resultats Nos resultats ont montre que: la distribution du Chlamydia trachomatis, de l’hepatite virale B et la syphilis a ete respectivement de 22,52%, 4,39%, 0,54%.De plus, nous avons observe une coinfection Chlamydia trachomatis hepatite virale B avec un taux de 2,74%. Par ailleurs la reinfection au Chlamydia trachomatis a ete rencontree dans 4,94% de cas. S’agissant du mode de transmission de ces affections 67,57% et 70,87% de femmes ne connaissaient pas la voie de transmission sexuelle pour le Chlamydia trachomatis et pour l’hepatite virale B respectivement, tandis que 91,2 % des femmes connaissaient la voie de transmission sexuelle pour la syphilis. Conclusion Le diagnostic d’une infection a Chlamydia trachomatis chez une patiente doit susciter le depistage de l’hepatite virale B. Introduction Sexually transmitted infections are still frequent in developing countries and particularly in Cameroon. The aim of this study was to determine the distribution of the following sexually transmitted infections: viral hepatitis B, Chlamydia trachomatis and syphilis in a population of women spontaneously visiting the Nkoldongo District Hospital in Yaounde as well as to evaluate possible co-infections among these three conditions and to bring out women’s prior knowledge of how sexual transmission occurs. Methods We conducted a prospective and descriptive study including 182 women aged between 18 and 48 years. These women underwent serologic testing for Chlamydia trachomatis with ELISA (General Biological Corp laboratory test kit. Hepatitis B virus was detected using immunochromatographic method (Human laboratory kit) while syphilis was detected using RPR agglutination (Biocentric Laboratories kit )and TPHA agglutination (Human laboratory kit) method. Results Our results showed that the distribution of Chlamydia trachomatis, viral hepatitis B and syphilis was 22.52%, 4.39%, 0.54% respectively. Moreover, we reported a Chlamydia trachomatis and Viral hepatitis B coinfection rate of 2.74%. In addition, Chlamydia trachomatis reinfection was detected in 4.94% of cases. Regarding the mode of transmission of these infections, 67.57% and 70.87% of women didn’t know how Chlamydia trachomatis and viral hepatitis sexual transmission could occur respectively, while 91.2% of women knew how was syphilis spread. Conclusion The diagnosis of chlamydia trachomatis infection should prompt screening for viral hepatitis B.

[Sero-epidemiological study of three sexually transmitted infections: Chlamydia Trachomatis, Hepatitis B, Syphilis. A case study conducted at the Nkoldongo District Hospital in Yaoundé].

INTRODUCTION: les infections sexuellement transmissibles sevissent toujours dans les pays en voie de developpement et particulierement au Cameroun. Le but de notre etude est de determiner la distribution des infections sexuellement transmissibles suivantes: l’hepatite virale B, le Chlamydia trachomatis et de la syphilis dans une population de femmes venant consulter spontanement a l’Hopital de District de Nkoldongo a Yaounde, d’evaluer d’eventuelles coinfections entre ces trois affections et de ressortir les connaissances de ces femmes sur leur mode de transmission sexuelle. METHODES: notre etude prospective et descriptive a porte sur 182 femmes dont l’âge variait entre 18 et 48 ans. Les femmes ont ete testees serologiquement pour le Chlamydia trachomatis par une methode ELISA (kit des laboratoires General Biological Corp). L’hepatite virale B a ete depistee par une methode immunochromatographique (kit des laboratoires Human) et la syphilis par une methode d’agglutination en ce qui concerne le RPR (Kit des laboratoires Biocentric) et le TPHA (kit des laboratoires Human). RESULTATS: nos resultats ont montre que: la distribution du Chlamydia trachomatis , de l’hepatite virale B et la syphilis a ete respectivement de 22,52%, 4,39%, 0,54%.De plus, nous avons observe une coinfection Chlamydia trachomatis hepatite virale B avec un taux de 2,74%. Par ailleurs la reinfection au Chlamydia trachomatis a ete rencontree dans 4,94% de cas. S’agissant du mode de transmission de ces affections 67,57% et 70,87% de femmes ne connaissaient pas la voie de transmission sexuelle pour le Chlamydia trachomatis et pour l’hepatite virale B respectivement, tandis que 91,2 % des femmes connaissaient la voie de transmission sexuelle pour la syphilis. CONCLUSION: le diagnostic d’une infection a Chlamydia trachomatis chez une patiente doit susciter le depistage de l’hepatite virale B.

Etude séro-epidémiologique de trois infections sexuellement transmissibles (Chlamydia Trachomatis, Hépatite B, Syphilis): cas de l’Hôpital de District de Nkoldongo à Yaoundé

Bonglaisin Julius Nsawir

Papers

Detection of Antimicrobial Resistance, Pathogenicity, and Virulence Potentials of Non-Typhoidal Salmonella Isolates at the Yaounde Abattoir Using Whole-Genome Sequencing Technique

[Sero-epidemiological study of three sexually transmitted infections: Chlamydia Trachomatis, Hepatitis B, Syphilis. A case study conducted at the Nkoldongo District Hospital in Yaoundé].

Etude séro-epidémiologique de trois infections sexuellement transmissibles (Chlamydia Trachomatis, Hépatite B, Syphilis): cas de l’Hôpital de District de Nkoldongo à Yaoundé