Serotype Typhi Research Articles

Restraining the multidrug efflux transporter STY4874 of Salmonella Typhi by reserpine and plant extracts.

Efflux-mediated multidrug resistance is a well-known phenomenon facilitated by multidrug resistant (MDR) transporters. One of the approaches to counteract efflux-mediated resistance is the use of MDR pump inhibitors, and thus be used in combination with the conventional antibiotics to treat deadly diseases like typhoid fever. We have previously reported that STY4874, an efflux transporter of Salmonella serotype Typhi, exhibited promising characteristics as MDR pump. In this study, we aimed to get an insight into possible STY4874 inhibitors of plant origin. STY4874 was overexpressed in Escherichia coli and extracts from pomegranate peel, milk thistle seeds and reserpine, a synthetic plant alkaloid, were screened for inhibition of ciprofloxacin efflux. The extracts of milk thistle seeds and reserpine when incubated with ciprofloxacin showed statistically significant STY4874-mediated inhibitory activity, rendering the efflux pump inactive and hence early growth inhibition of host cells compared with cells expressing efflux pump and incubated only with ciprofloxacin. This efflux pump inhibitory activity was further confirmed by time-kill experiments. This study is the first to report on efflux pump inhibition of S. Typhi STY4874 and results can be extended towards its close homologues such as MdfA and MdtM from E. coli. SIGNIFICANCE AND IMPACT OF THE STUDY: Understanding and combating resistance governed by multidrug efflux transporters is an ongoing research intensive area, affecting treatment of various nosocomial and endemic/epidemic infections. Confronting drug resistance requires that inhibitors debilitating the underlying mechanisms should be included in combination therapy. One such example is the prescription of clavulanic acid as combination therapy with amoxicillin, collectively called as co-amoxiclav to combat β-lactamase-mediated resistance. However, research related to finding the inhibitors of efflux transporters, the resistance mechanism distinct from β-lactamase mediated resistance is at an early stage. The current study finds that plant-derived inhibitors can be an option towards restraining efflux-mediated resistance.

ANTIMICROBIAL SUSCEPTIBILITY IN CULTURE POSITIVE ENTERIC FEVER

INTRODUCTION: Enteric fever includes typhoid and paratyphoid fever. Peak incidence is seen in children 5–15 years of age; but in regions where the disease is highly endemic, as in India, children younger than 5 years of age may have the highest infection rates. There are about 22 million new typhoid cases occur each year. Young children in poor, resource limited areas, who make up the majority of the new cases and there is a mortality figures of 215,000 deaths annually. A sharp decline in the rates of complications and mortality due to typhoid fever is observed as a result of introduction of effective antibiotic therapy since 1950s. MDR-ST became endemic in many areas of Asia, including India soon after multidrug-resistant strains of Salmonella enterica serotype typhi (MDR-ST) that were resistant to all the three first-line drugs then in use, namely chloramphenicol, amoxycillin and co-trimoxazole emerged in early 1990s.
 MATERIAL AND METHODS: Only blood culture or bone marrow culture positive cases were included. The patients with culture isolated enteric fever were included in the study. Antimicrobial susceptibility testing was carried out by disk diffusion method using antibiotic discs. The analysis of the antimicrobial susceptibility was carried out as per CLSI interpretative guidelines.
 RESULTS: A total of 82 culture positive cases were included in the present study. 80 culture isolates were from blood culture and 2 from the bone marrow culture. Salmonella entericasubspecies enterica serovartyphi (S typhi) was isolated from 67 (81.70%) patients while Salmonella enterica subspecies entericaserovarparatyphi (S paratyphi A) was isolated from 13 (15.85%) cases and 2 (2.44%) were Salmonella enterica subspecies entericaserovarschottmuelleri (S paratyphi B). Of the 82 cases 65(79.3%) isolates were resistant to ciprofloxacin, 17 (20.7%) were resistant to nalidixic acid, one (1.2%) case each was resistant to Cefotaxime and ceftriaxone, 2 (2.4%) were resistant to chloramphenicol, 10 (12.2%) were resistant and to cotrimoxazole 3 (3.7%) were resistant.
 CONCLUSION: In a culture positive cases 65(79.3%) isolates were resistant to ciprofloxacin and 17 (20.7%) were resistant to nalidixic acid. Multidrug resistant isolates were 65(79.3%).

Laboratory characterisation of Salmonella enterica serotype Typhi isolates from Zimbabwe, 2009\u20132017

BackgroundTyphoid fever remains a major public health problem in Zimbabwe with recurrent outbreaks reported since 2009. To provide guidance on appropriate treatment choice in order to minimise the morbidity and mortality of typhoid fever and prevent large scale outbreaks, we investigated the antimicrobial susceptibility patterns, prevalence of Salmonella enterica serotype Typhi (S. Typhi) H58 haplotype and molecular subtypes of S. Typhi from outbreak strains isolated from 2009 to 2017 in Zimbabwe and compared these to isolates from neighbouring African countries.MethodsAntimicrobial susceptibility testing was performed on all isolates using the disk diffusion, and E-Test, and results were interpreted using Clinical and Laboratory Standards Institute (CLSI) guidelines (2017). S. Typhi H58 haplotype screening was performed on 161 (58.3%) isolates. Pulsed-field gel electrophoresis (PFGE) was performed on 91 selected isolates across timelines using antibiotic susceptibility results and geographical distribution (2009 to 2016).ResultsBetween 2009 and 2017, 16,398 suspected cases and 550 confirmed cases of typhoid fever were notified in Zimbabwe. A total of 276 (44.6%) of the culture-confirmed S. Typhi isolates were analysed and 243 isolates (88.0%) were resistant to two or more first line drugs (ciprofloxacin, ampicillin and chloramphenicol) for typhoid. The most common resistance was to ampicillin-chloramphenicol (172 isolates; 62.3%). Increasing ciprofloxacin resistance was observed from 2012 to 2017 (4.2 to 22.0%). Out of 161 screened isolates, 150 (93.2%) were haplotype H58. Twelve PFGE patterns were observed among the 91 isolates analysed, suggesting some diversity exists among strains circulating in Zimbabwe. PFGE analysis of 2013, 2014 and 2016 isolates revealed a common strain with an indistinguishable PFGE pattern (100% similarity) and indistinguishable from PFGE patterns previously identified in strains isolated from South Africa, Zambia and Tanzania.ConclusionsResistance to first line antimicrobials used for typhoid fever is emerging in Zimbabwe and the multidrug resistant S. Typhi H58 haplotype is widespread. A predominant PFGE clone circulating in Zimbabwe, South Africa, Zambia and Tanzania, argues for cross-border cooperation in the control of this disease.

Detection and Molecular Characterization of Staphylococci from Eggs of Household Chickens.

Eggs are a healthy and nutritious food source, but may be contaminated by bacteria. Previous studies have reported the presence of staphylococci in eggs of farmed chickens, but no study has evaluated the staphylococcal population of eggs from household chickens. In this study, staphylococci from eggs (n = 275) of household chickens collected from November 2016 to March 2017 from different villages of Khyber Pakhtunkhwa province, Pakistan, were characterized. Seven species of staphylococci were identified from 65 eggs, including the predominant species, Staphylococcus xylosus (49/275; 17.8%). S. xylosus isolates (n = 73) were tested for antimicrobial susceptibility, presence of resistance genes, genetic relatedness, and inhibitory activity against other bacteria. The majority of isolates were resistant to oxacillin (83.6%) and tetracycline (24.7%), but also exhibited resistance to daptomycin and linezolid (5.5% each). Of the 10 resistance genes tested, isolates were only positive for mecA (35.6%; 26/73), mecC/C1 (2.7%; 2/73), and tet(K) (14/73; 19%). Using pulsed-field gel electrophoresis (PFGE), nine clusters had identical PFGE patterns. Isolates produced inhibitory activity against a broad spectrum of bacteria; 20.5%, 19.2%, 17.8%, and 16.4% of S. xylosus were able to inhibit growth of Salmonella enterica serotype Typhi, methicillin-susceptible Staphylococcus aureus, Escherichia coli, and methicillin-resistant Staphylococcus aureus, respectively. This study demonstrated the presence of genetically related antimicrobial-resistant S. xylosus from eggs from household chickens. Like table eggs, eggs of household chickens also contain staphylococci that may be resistant to antimicrobials used to treat human infections. These data will allow comparison between staphylococci from eggs from different sources and may indicate the relative safety of eggs from household chickens. Further study of these egg types and their microbial composition is warranted.

The global burden of typhoid and paratyphoid fevers: a systematic analysis for the Global Burden of Disease Study 2017

SummaryBackgroundEfforts to quantify the global burden of enteric fever are valuable for understanding the health lost and the large-scale spatial distribution of the disease. We present the estimates of typhoid and paratyphoid fever burden from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, and the approach taken to produce them.MethodsFor this systematic analysis we broke down the relative contributions of typhoid and paratyphoid fevers by country, year, and age, and analysed trends in incidence and mortality. We modelled the combined incidence of typhoid and paratyphoid fevers and split these total cases proportionally between typhoid and paratyphoid fevers using aetiological proportion models. We estimated deaths using vital registration data for countries with sufficiently high data completeness and using a natural history approach for other locations. We also estimated disability-adjusted life-years (DALYs) for typhoid and paratyphoid fevers.FindingsGlobally, 14·3 million (95% uncertainty interval [UI] 12·5–16·3) cases of typhoid and paratyphoid fevers occurred in 2017, a 44·6% (42·2–47·0) decline from 25·9 million (22·0–29·9) in 1990. Age-standardised incidence rates declined by 54·9% (53·4–56·5), from 439·2 (376·7–507·7) per 100 000 person-years in 1990, to 197·8 (172·0–226·2) per 100 000 person-years in 2017. In 2017, Salmonella enterica serotype Typhi caused 76·3% (71·8–80·5) of cases of enteric fever. We estimated a global case fatality of 0·95% (0·54–1·53) in 2017, with higher case fatality estimates among children and older adults, and among those living in lower-income countries. We therefore estimated 135·9 thousand (76·9–218·9) deaths from typhoid and paratyphoid fever globally in 2017, a 41·0% (33·6–48·3) decline from 230·5 thousand (131·2–372·6) in 1990. Overall, typhoid and paratyphoid fevers were responsible for 9·8 million (5·6–15·8) DALYs in 2017, down 43·0% (35·5–50·6) from 17·2 million (9·9–27·8) DALYs in 1990.InterpretationDespite notable progress, typhoid and paratyphoid fevers remain major causes of disability and death, with billions of people likely to be exposed to the pathogens. Although improvements in water and sanitation remain essential, increased vaccine use (including with typhoid conjugate vaccines that are effective in infants and young children and protective for longer periods) and improved data and surveillance to inform vaccine rollout are likely to drive the greatest improvements in the global burden of the disease.FundingBill & Melinda Gates Foundation.

Emergence of Extensively Drug-Resistant Salmonella Typhi Infections Among Travelers to or from Pakistan - United States, 2016-2018.

In February 2018, a typhoid fever outbreak caused by Salmonella enterica serotype Typhi (Typhi), resistant to chloramphenicol, ampicillin, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporins, was reported in Pakistan. During November 2016-September 2017, 339 cases of this extensively drug-resistant (XDR) Typhi strain were reported in Pakistan, mostly in Karachi and Hyderabad; one travel-associated case was also reported from the United Kingdom (1). More cases have been detected in Karachi and Hyderabad as surveillance efforts have been strengthened, with recent reports increasing the number of cases to 5,372 (2). In the United States, in response to the reports from Pakistan, enhanced surveillance identified 29 patients with typhoid fever who had traveled to or from Pakistan during 2016-2018, including five with XDR Typhi. Travelers to areas with endemic disease, such as South Asia, should be vaccinated against typhoid fever before traveling and follow safe food and water practices. Clinicians should be aware that most typhoid fever infections in the United States are fluoroquinolone nonsusceptible and that the XDR Typhi outbreak strain associated with travel to Pakistan is only susceptible to azithromycin and carbapenems.

Use of pefloxacin as a surrogate marker to detect ciprofloxacin susceptibility in Salmonella enterica serotypes Typhi and Paratyphi A.

To determine the use of pefloxacin as a surrogate marker to detect fluoroquinolone (ciprofloxacin) susceptibility against Salmonella enterica serotypes Typhi and Paratyphi A. The prospective, descriptive cross-sectional study was conducted at the Aga Khan University Hospital, Karachi, from September 2016 to March 2018, and comprised Salmonella Typhi and Paratyphi A isolates of blood cultures. Disk susceptibility tests and broth microdilution to test minimum inhibitory concentration were performed as per standard guidelines. Data was analysed using SPSS 21. Of the 138 isolates, 91(66%) were intermediate resistant to ciprofloxacin but were resistant to pefloxacin, 42(30%) were resistant to both ciprofloxacin and pefloxacin, and 5(4%) were susceptible to both ciprofloxacin and pefloxacin. Of the isolates that were intermediate resistant to ciprofloxacin, 85(93%) had minimum inhibitory concentration range0.12-0.5mg\L, while 6(7%) had MIC>1mg\L (p<0.0001). Pefloxacin disk diffusion test was found to be reliable in detecting fluoroquinolone resistance among enteric fever causing Salmonella.

Pengembangan Prekultur Oxgall sebagai Sampel Klinis untuk Deteksi Salmonella typhi dengan Metode Real-time PCR

Demam tifoid merupakan beban kesehatan masyarakat yang signifikan di negara berpenghasilan rendah yang disebabkan oleh Salmonella enterica serotype typhi (S.typhi). Manifestasi klinis demam tifoid bervariasi dan tidak spesifik, sehingga membuat diagnosis menjadi sulit. Dengan menggunakan oxgall untuk pra-inkubasi sebagai media kultur selektif sebelum amplifikasi Real-time PCR (RT-PCR) pada wholeblood menghasilkan diagnostic yang cepat dan sensitif. Tujuan dari penelitian ini adalah untuk mengetahui kinerja oxgall sebelum amplifikasi RT-PCR untuk deteksi Salmonella sp . Sebelum proses pengambilan sampel, dilakukan optimasi spike sampel untuk mengetahui bahwa reagen yang digunakan baik untuk spesimen klinis. Dalam proses sampel, sampel wholeblood diambil dari 30 pasien dengan positif Widal tes. Sampel darah vena dari pasien demam tifoid diambil pada hari diagnosis; 5 ml untuk kultur darah, dan 5 ml untuk RT-PCR. Bakteri ditanam di oxgall 10% (standar mikrobiologi laboratorium klinik) dan diinkubasi selama 6 jam (37 ° C) sebelum DNA bakteri diisolasi untuk deteksi RT-PCR. Hasil penelitian menunjukkan bahwa reagen RT-PCR baik digunakan untuk sampel klinis dan kultur darah lebih baik daripada RT-PCR dengan menggunakan oxgall (hasil kultur darah positif lebih dari 24 jam). Hal ini menunjukkan bahwa harus ada penelitian lebih lanjut mengenai durasi inkubasi dan konsentrasi oxgall pada RT-PCR dan pemilihan sampel klinis.

Scavenger birds exploiting rubbish dumps: Pathogens at the gates.

Different bacteria are present in rubbish dumps used as food resources by various bird species. Birds may be good indicators of the presence of zoonotic diseases in these sites since they can be infected with zoonotic pathogens by foraging on organic waste, and can also act as carriers. We studied if foraging in rubbish dumps increases the occurrence of Salmonella spp. and Chlamydia psittaci in American black vultures (Coragyps atratus, hereafter black vultures) from northwest Patagonia. We compared these pathogens isolated from or detected in cloacae and oropharynx swabs in two different groups of black vultures: individuals trapped in (a) the Patagonian wild steppe and (b) in a rubbish dump. We found that black vultures are colonized by Salmonella spp. (particularly Salmonella enterica serotypes Typhi, Paratyphi A, Salmonella enterica subsp.arizonae) and Chlamydia psittaci. Interestingly, there were differences in the prevalence of Salmonella spp., especially Salmonella Typhi, between individuals foraging in the rubbish dump and the steppe, but not in the prevalence of Chlamydia psittaci. The pathogens isolated from black vultures may impact their health status but could also have health impacts in other bird species and even humans. In fact, Salmonella Typhi can cause severe disease in humans leading to death. Our results are globally relevant given that bacterial infections from rubbish dumps may affect different species exploiting these sites around the world. There is a need to better control pathogens in rubbish dumps to avoid the risk of infecting wildlife, which could act as potential dispersers and reservoirs of these pathogens.

918. Typhoid Fever in the US Pediatric Population, 1999–2015, and the Potential Benefits of New Vaccines

BackgroundIn the United States, typhoid fever is rare. About 300 typhoid cases are reported to CDC annually through the National Typhoid and Paratyphoid Fever Surveillance (NTPFS) system. Most are acquired during international travel and while visiting friends and relatives. CDC recommends pretravel vaccination of at-risk children with one of two currently available vaccines: oral (age ≥6 years) or injectable (age ≥2 years). In anticipation of licensure of new protein-conjugate typhoid vaccines that could be administered to children ≥6 months old, we characterized clinical, epidemiologic, and antimicrobial resistance data of pediatric typhoid fever cases reported to CDC.MethodsWe reviewed laboratory-confirmed Salmonella enterica serotype Typhi infections reported to NTPFS and antimicrobial resistance data on Typhi isolates in the National Antimicrobial Resistance Monitoring System (NARMS) from 1999 to 2015.ResultsOf 2,051 pediatric (≤18 years) cases of typhoid fever, 80% had traveled internationally within 30 days of illness onset (most frequently to South Asia [82%]), 81% were hospitalized (median duration 6 days; range 0–77 days), and none died. Eight hundred twenty-seven (40%) were <6 years old; 219 (26%) were 6 months–2 years old. While 76% of pediatric cases were vaccine eligible (travelers ≥2 years old), only 6% were known to be vaccinated. Of 2,020 isolates tested for antimicrobial susceptibility, 1,211 (60%) had decreased susceptibility or resistance to ciprofloxacin, of which 277 (23%) were also resistant to ampicillin, chloramphenicol, and trimethoprim/sulfamethoxazole (multidrug-resistant [MDR]). None were resistant to ceftriaxone or azithromycin. MDR isolates were more likely in children than adults (16% vs. 9%, P < 0.05) and in travel-associated than domestically acquired cases (16% vs. 6%, P < 0.05).ConclusionAmong pediatric cases of typhoid fever, 94% of currently vaccine-eligible travelers were unvaccinated. Emphasis on current vaccine indications and an effective pretravel typhoid vaccine for children between 6 months and 2 years old available during routine immunization visits could begin to reduce the burden of disease, and help prevent drug-resistant infections, in this vulnerable age group. Disclosures All authors: No reported disclosures.

Outbreak investigation of ceftriaxone-resistant Salmonella enterica serotype Typhi and its risk factors among the general population in Hyderabad, Pakistan: a matched case-control study

Pakistan is currently facing the largest outbreak of ceftriaxone-resistant Salmonella enterica serotype Typhi described to date. Here we aimed to report the outbreak investigation done in Hyderabad, Pakistan, and identify disease risk factors. We did an age-matched case-control (1:4) study, in which cases of ceftriaxone-resistant S Typhi were identified from active sentinal sites (three hospitals in Hyderabad, Pakistan), community, and laboratory-based surveillance. Ceftriaxone-resistant S Typhi infection (ie, resistance to ampicillin, chloramphenicol, co-trimoxazole, fluoroquinole, and ceftriaxone) was confirmed using blood culture. Healthy participants (controls) were enrolled for the first 200 people (cases) with ceftriaxone-resistant S Typhi. A structured questionnaire was administered to identify exposures 4 weeks before the illness (cases) or enrolment (controls). Cases were included if written informed consent was provided. Four controls were selected from the same community as the corresponding case, matched on age, being healthy at the time of enrolment, and with no febrile illness in the 4 weeks before enrolment. Samples of drinking water from households and community water sources (ie, hand pumps or taps in common areas outside households) were collected for testing. Conditional logistic regression analysis was used to assess the risk factors for ceftriaxone-resistant S Typhi outbreak in Hyderabad. Between Nov 30, 2016, and Dec 30, 2017, 486 people with ceftriaxone-resistant S Typhi were identified from Hyderabad. Of the 486 cases, 296 (61%) were male and 447 (92%) were aged 15 years or younger. Several factors were significantly associated with acquisition of ceftriaxone-resistant S Typhi, including male sex (adjusted odds ratio [aOR] 1·53, 95% CI 1·06-2·21), eating outside of the house (aOR 1·48, 1·01-2·19), exposure to a patient with S Typhi infection (aOR 3·81, 2·21-6·83), and a history of antimicrobial use (aOR 4·25, 2·53-7·13). Nine (69%) of 13 water samples taken from the households of people with ceftriaxone-resistant S Typhi infection were positive for Escherichia coli, indicating faecal contamination. S Typhi DNA was detected in 12 (22%) of 55 water samples from community water sources. Geospatial mapping showed clustering of cases around sewerage lines. Hyderabad faces the largest reported outbreak of ceftriaxone-resistant S Typhi. The outbreak is suspected to be attributed to the contaminated drinking water, especially the mixing of sewage with drinking water. The risk of ceftriaxone-resistant S Typhi infection is increased among children aged 15 years and younger, male individuals, and those eating outside the house. Vaccination and chlorination of water are recommended for the containment of the outbreak. None.

Multi-drug resistant Salmonella enterica serovar Typhi isolates with reduced susceptibility to ciprofloxacin in Kenya

BackgroundTyphoid fever remains a public health concern in developing countries especially among the poor who live in informal settlements devoid of proper sanitation and clean water supply. In addition antimicrobial resistance poses a major challenge in management of the disease. This study assessed the antimicrobial susceptibility patterns of Salmonella enterica serotype Typhi (S. Typhi) isolated from typhoid fever cases (2004–2007).MethodsA cross sectional study was conducted on 144 archived S. Typhi isolates (2004–2007) tested against 11 antimicrobial agents by quality controlled disk diffusion technique. Isolates resistant to ampicillin, chloramphenicol, and cotrimoxazole were considered Multidrug resistant (MDR). Thirty MDR isolates were selected randomly and further tested using minimum inhibitory concentration (MIC) E-test.ResultsSixteen percent (23/144) of the isolates were susceptible to all the antibiotics tested while 68% were resistant to three or more of the 11 antibiotics tested. The isolates showed a high susceptibility to ceftriaxone (94%) and gentamicin (97%). A high percentage of resistance was observed for the conventional first-line antibiotics; ampicillin (72%), chloramphenicol (72%), and cotrimoxazole (70%). Sixty-nine percent of the isolates (100/144) showed reduced susceptibility to ciprofloxacin. All the 30 (100%) isolates selected for MIC test were susceptible to amoxicillin-clavulanic acid. All except one of the 30 isolates were susceptible to ceftriaxone while majority 21 (70%) recorded an intermediate susceptibility to ciprofloxacin with MIC of 0.12–0.5 μg/mL.ConclusionA large proportion of S. Typhi isolates were MDR and also showed reduced susceptibility to ciprofloxacin. Fluoroquinolone resistance is emerging and this may pose a challenge in treatment of typhoid in future. There is need for routine surveillance to monitor this phenotype in clinical settings.

Evaluation of Sensitivity and Specificity of ELISA and PBA for IgM Detection to LPS Antigen of Salmonella Typhi

The high prevalence of typhoid fever in developing countries, includingIndonesia has prompted the exploration of various serologic tests and antigen detectionmethod to obtain an early and accurate diagnosis of patients with typhoid fever.Although typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi,there is still an urgent need for the rapid, simple serological tests and evaluation ofeffective and appropriate diagnostics for typhoid fever. In this study, we evaluated and compared the sensitivity and specifity of ELISA and Passive Bacterial Agglutination(PBA) as an agglutination-based serological test to LPS antigen of Salmonella Typhiand the effectiveness of local antigen in detecting the production of specific antibody(IgM) to patient with typhoid fever. We collected serum sample of 50 suspected typhoidfever from DR. Wahidin Sudirohusodo General Hospital, Daya General Hospital, GowaGeneral Hospital and Kassi-Kassi Public Health Center in Makassar, South of Sulawesi.They were grouped based on sex, duration of fever, and age. Serum antibody titer weremeasured by ELISA and PBA. Data were analiyzed satistically by using cross tabulationand chi-square (CI = 95%). The Result of this study showed that PBA technique has thelevel of sensitivity and specifity respectively 100% and 92 %, while ELISA was 84% and28%. It suggested that PBA has a greater level of sensitivity and specifity than ELISA.We also showed that LPS antigen that we obtained from local isolate of SalmonellaTyphi, can be used as a standard antigen in diagnosing typhoid fever.

Community-based prevalence of typhoid fever, typhus, brucellosis and malaria among symptomatic individuals in Afar Region, Ethiopia.

BackgroundIn sub-Saharan Africa, where there is the scarcity of proper diagnostic tools, febrile illness related symptoms are often misdiagnosed as malaria. Information on causative agents of febrile illness related symptoms among pastoral communities in Ethiopia have rarely been described.MethodsIn this a community based cross-sectional survey, we assessed the prevalence of typhoid fever, typhus, brucellosis and malaria among individuals with a set of given symptoms in Amibara district, Afar Region, Ethiopia. Blood samples were collected from 650 study participants, and examined by Widal and Weilfelix direct card agglutination test (DCAT) as well as test tube based titration test for Salmonella enterica serotype Typhi (S. Typhi) and Rickettsia infections. Rose Bengal Plate Test (RBPT) and Complement Fixation Test (CFT) were used to screen Brucella infection. Thin and thick blood smears were used to diagnosis malaria.ResultsOut of 630 sera screened by DCAT, 83 (13.2%) were reactive to H and/or O antigens for S. Typhi infection. Among these, 46 (55.4%) were reactive by the titration test at the cut off value ≥ 1:80. The combined sero-prevalence for S. Typhi by the two tests was 7.3% (46/630). The seroprevalence for Rickettsia infection was 26.2% (165/630) by DCAT and 53.3% (88/165) by the titration test at the cut off value ≥ 1:80. The combined sero-prevalence for Rickettsia infection by the two tests was 14.0% (88/630). The sero-prevalence for Brucella infection was 12.7% (80/630) by RBPT, of which 28/80 (35%) were positive by CFT. The combined sero-prevalence for Brucella infection by the two tests was 4.4% (28/630). Out 650 suspected individuals for malaria, 16 (2.5%) were found positive for P. falciparum infection.ConclusionIn this study, typhoid fever, typhus, brucellosis and malaria were observed among symptomatic individuals. The study also highlighted that brucellosis cases can be misdiagnosed as malaria or other disease based solely on clinical diagnosis. Therefore, efforts are needed to improve disease awareness and laboratory services for the diagnosis of brucellosis and other zoonotic diseases to identify other causes of febrile illness in this pastoral setting.

Comparison of Antibody Titre Against Salmonella Species among Healthy Individuals and Febrile Patients

Background: Widal tube agglutination test is a widely used laboratory test for diagnosis of enteric fever especially in resource limited countries where blood culture are not routinely available. We studied the titres from different groups including febrile and healthy populations in order to identify the significant agglutination titre. Materials and Methods: This was a hospital based cross-sectional study. Subjects were divided into three groups: 1) 60 healthy blood samples from volunteer students, 2) 60 febrile non-typhoidal cases and 3) 58 culture positive patient for enteric fever. Results: Among 60 apparently healthy volunteers, agglutination of ≥ 1:20 for anti O and anti-H titres against serotype Typhi were seen in 40 and 46 samples respectively. A significant proportion of sample had a titre of ≥1:80 (n=19) and 1:160 (n=14) for anti O and anti-H titres against serotype Typhi respectively among healthy individuals. Similar observations were seen in febrile non typhoidal cases except for one which had a titre of ≥1:320 for anti O and anti-H titres against serotype Typhi. In blood culture positive typhoid cases, 56 samples showed agglutinations of ≥1:80 for both anti O and anti-H titres against serotype Typhi. However two of the total sample tested showed no agglutinations. In all cases from three groups, anti-H titre for S. enterica serotype Paratyphi A and B were below 1:80. Conclusions: Widal test can be used as presumptive diagnostic tool in all the suspected cases of enteric fever if the titres are specifically raised.Keywords: enteric fever; titre; widal aggultination test.

Exposure to Plant Extract Causes the Variation of Antibiotic Susceptibility of Two Bacterial Strains (Salmonella Serotype Typhi and Staphylococcus aureus)

Exposure to Plant Extract Causes the Variation of Antibiotic Susceptibility of Two Bacterial Strains (Salmonella Serotype Typhi and Staphylococcus aureus)

Prevalence and Antibiogram Pattern of Salmonella enterica Serotypes inGarhwal Region: First Report from Foothills of Himalayas

Introduction: Enteric fever, caused by Salmonella enterica subsp. Enterica serotype Typhi and Paratyphi, is endemic in India with an incidence of 102–2219/100,000 populations. The definitive diagnosis of enteric fever in patients with compatible clinical picture is isolation of Salmonellae from blood, bone marrow, stool or urine, and demonstration of four‑fold rise in antibody titer to both O and H antigen of the organism between acute and convalescent‑phase sera. Aim: The aim of the study was to study the prevalence of various serotypes of S. enterica and their antibiogram in foot hills of Himalayas. Materials and Methods: During February 2012–January 2013, all clinically suspected patients were screened for enteric fever by Widal tube agglutination test. For the isolation of etiology, venous blood, stool and urine specimen were obtained from patients with antibody titer of ≥80 and 160 for anti‑O agglutinin and anti‑H agglutinin of Salmonella typhi, respectively, and ≥20 for anti-H agglutinin of S. paratyphi A and S. paratyphi B. Characterization and antibiogram determination of the isolates was done by conventional microbiological methods including Kirby–Bauer’s disc diffusion technique. Result: Among 1173 suspected cases, 373 showed a high titer of antibodies against O (≥80), H (≥160), AH (≥20), and BH (≥20) antigens. A total of 81 isolates were obtained from 76 patients (29 from blood and 49 from stool and three from urine), of which 54 were identified as Salmonella typhi, 20 as Paratyphi A and seven as Paratyphi B. Extended‑spectrum beta‑lactamase production was observed in four isolates of S. typhi. Ciprofloxacin followed by co‑trimoxazole was resistant to 46.5 and 36.5% of the isolates, respectively. Conclusion: This report indicates a significant percentage of drug resistance in S. enterica serotypes in Garhwal region. Periodic monitoring of the antibiogram pattern along with the implementation of strict antibiotic policies and patient education is needed. Keywords: Blood culture, extended‑spectrum beta‑lactamase, Salmonella typhi, typhoid fever, Widal test.

Pathogen killing pathogen: antimicrobial substance from Acinetobacter active against foodborne pathogens.

Antimicrobial substances (AMS) produced by bacteria may reduce or prevent the growth of pathogenic and spoilage microorganisms in food. In this study, 16 isolates of Acinetobacter baumannii/calcoaceticus (ABC) complex, previously obtained from reconstituted infant milk formula (IMF) samples and the preparation and distribution utensils from the nursery of a public hospital, were used to screen for AMS production. Antimicrobial substance production and spectrum of activity assays were performed by agar-spot assay. Optimization of growth conditions for AMS production was also evaluated. Three (17.6%) isolates, namely JE3, JE4, and JE6, produced AMS against the principal indicator strain Salmonella enterica subsp. enterica serotype Typhi ATCC 19214. JE6 was also able to inhibit strains of Klebsiella pneumoniae, Proteus vulgaris, and Bacillus cereus, a Gram-positive bacteria. Remarkably, JE6 was able to inhibit all the tested resistant and multidrug-resistant (MDR) strains of the ABC complex and Shigella dysenteriae associated with IMF and utensils, indicating a potentially valuable application. AMS produced by JE6 does not appear to be affected by proteolytic enzymes and the producer strain showed specific immunity to its own AMS. This study highlights AMS produced by Acinetobacter with applications against MDR spoilage and foodborne pathogens - some of them, infectious disease causing agents - which, to our knowledge, has not been previously described.

First report on antimicrobial resistance and molecular characterisation of Salmonella enterica serotype Typhi isolated from human specimens in Luanda, Angola.

Typhoid fever is a common infection in Africa and, despite scarce surveillance reports, its incidence is commonly considered high by the Angolan health system. Drug-resistant Salmonella enterica serotype Typhi has emerged, making antimicrobial susceptibility testing essential to provide clinical guidance. This is the first report analysing the antimicrobial resistance patterns and population structure of the few S. enterica ser. Typhi isolated from patients with typhoid fever in Luanda, Angola. Isolates were collected by the Angolan National Institute of Public Health between September 2013 and May 2014. Ten isolates were identified by the API 20E system and serotyping, and the genus was confirmed by PCR. All isolates were tested for antibiotic susceptibility, and the presence of resistance genes [blaCTX-M, blaSHV, blaTEM, blaOXA-1, several plasmid-borne genes encoding AmpC β-lactamases, sul and qnr genes, dfrIa, dfrA12, aac(6')-Ib, cmlA and floR] were screened by PCR. Isolates were typed by PFGE and MLST. Several isolates were identified with resistance to trimethoprim/sulfamethoxazole (n=6), β-lactams (n=5) and chloramphenicol (n=1) and reduced susceptibility to ciprofloxacin (n=2). PFGE revealed eight closely related restriction patterns, and MLST grouped these into three sequence types (ST1, ST2 and ST8), with ST2 being predominant. This first epidemiological report provides a preliminary description of S. enterica ser. Typhi strains circulating in Luanda and emphasises the need for continuous monitoring of this pathogen to provide information in order to implement better epidemiological strategies for the control of typhoid fever in Angola.

A Rare Case of Primary Anterior Chest Wall Abscess due to Salmonella Typhi in an Immunocompetent Male

A case of suspicious anterior chest wall mass due to Salmonella enterica serotype Typhi in a middle aged, non- diabetic male is being described. The infection was successfully treated with timely institution of antibiotic treatment. This case highlights the fact that a focal Salmonella infection involving the anterior chest wall should be considered as a differential diagnosis and not treated as tuberculosis empirically. Submission of specimens for microbiological analysis should be performed for an accurate diagnosis and management.