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Escherichia coli is one of the critical One Health pathogens due to its vast array of virulence and antimicrobial resistance genes. This study used multiplex PCR to determine the occurrence of virulence genes bfp, ompA, traT, eaeA, and stx1 among 50 multidrug-resistant (MDR) E. coli isolates from humans (n = 15), animals (n = 29), and the environment (n = 6) in Dar es Salaam, Tanzania. Their association with antimicrobial-resistant genes (ARGs) was determined using Principal Component Analysis (PCA). All 50/50 (100%) MDR E. coli isolates carried at least one virulence gene, with 19/50 (38%) carrying four genes, bfp + traT + eaeA + ompA. The findings showed a high occurrence of virulence genes bfp (82%), traT (82%), eaeA (78%), and ompA (72%); the study detected no stx1 in any of the isolates. In humans, the most detected virulence genes were bfp and traT 14/15 (93.3%); for poultry, it was eaeA 13/14 (92.9%); for pigs, was bfp and traT 13/15 (86.7%); while for river water, it was eaeA 6/6 (100%). The study observed no significant association between virulence genes and ARGs. PCA results show the genes ompA, traT, eaeA, and bfp contributed to the virulence of the isolates, and blaTEM, blaCTX-M, and qnrs contributed to ARGs. The PCA ellipses show that isolates from pigs had more virulence genes than those isolated from poultry, river water, and humans. The high frequency of numerous virulence genes in MDR E. coli isolates from humans, animals, and the environment indicates that these isolates have a very high potential to cause diseases that are difficult to treat because they are MDR.

Abstract Background Globally, urinary tract infections (UTIs) are the leading cause of hospital visits, especially among women. In many developing countries, especially in lower health facilities, the dipstick urinalysis is the most commonly requested test, as urine culture is not routinely performed. The dipstick test can potentially reduce the number of patients who could be treated with empirical antibiotics and reduce the burden of antibiotic resistance. The current study determined the utility of dipstick urinalysis in diagnosing UTIs using urine culture as a gold standard method. Methods A cross-sectional study was conducted between July and November 2021. The study involved 1327 outpatients attending lower health centres in Mwanza (n = 678) and Dar es Salaam (n = 649) regions. The samples were subjected to dipstick urinalysis (nitrite and leucocytes) and quantitative bacterial culture. Results Of all 1326 patient samples, 808(60.9%) and 48(3.6%) were positive for urinary leucocyte and nitrite, respectively, while significant urine culture was found in 364(27.4%). leucocyte test correctly diagnosed UTI in 283 (77.75%) and nitrite test in 36 (9.89%). The leucocytes and nitrites, in combination, exhibited a sensitivity of 79.40% and NPV of 85.24% but a lower specificity of 44.96% and a lower PPV of 35.29%. Urinary leucocyte test had a higher discrimination ability to detect urinary tract infection than urinary nitrite test (AUC = 0.073, 95% CI 0.043–0.103, p

Abstract Background Hospital sewage is a significant reservoir of antimicrobial-resistant pathogens and genes that pose a huge public health threat. In this study, we determined the occurrence of multidrug-resistant Escherichia coli and Klebsiella pneumoniae in sewage flowing from a referral hospital through the urban sewage system to the point of discharge in the Indian Ocean. Results A total of 400 sewage samples were collected, yielding 517 isolates. Of these, 32.3% (167/517) were from hospital sewage, while 67.7% (350/517) were from the community. E. coli was the most common isolate (44.5% (230/517)), followed by K. pneumoniae at 27.3% (141/517), and other gram-negative bacteria constituted 28.2% (146/517) of the isolates. Multidrug resistance (MDR) was seen in 80.9% (186/230) E. coli and 71.6% (101/141) K. pneumoniae. Of the MDR isolates, 27.2% (78/287) were resistant to four different classes of antibiotics, while 6.9% (20/287) exhibited resistance to eight classes. The most frequent MDR pattern was PEN/CEP/TET/QNL/SUL, seen in 14.2% (38/287) of the isolates. The isolation frequency of MDR E. coli and K. pneumoniae at different sampling sites was high, being 47.6% in hospital chambers, 62.0% in hospital ponds, 58.1% in the treated hospital wastewater, and 55.6% in the community stream draining into the Indian Ocean. Extended spectrum beta-lactamase production was observed in 40% (92/230) of E. coli and 36.2% (51/141) of K. pneumoniae isolates. Resistance to quinolones among E. coli was 54.8% (126/230) and was 39.7% in K. pneumoniae (56/141). Carbapenem resistance in E. coli was 39.6% (91/230), while among K. pneumoniae isolates was 32.6% (46/141). Conclusions We found high proportions of multidrug-resistant E. coli and K. pneumoniae in the wastewater flowing from the hospital through the community sewage system to the point where it enters the Indian Ocean. Biological treatment did not significantly reduce the proportion of resistant bacteria, posing a very serious public health threat. The release of these highly resistant pathogens into the Indian Ocean is of international concern.

Abstract Background Previous studies have shown significant differences and lack clarity on whether resistance to either isoniazid or rifampicin can predict multidrug resistance tuberculosis (MDR-TB). Some consider rifampicin resistance to be a surrogate for MDR-TB. We, therefore, conducted this study to determine resistance to either isoniazid or rifampicin can predict MDR-TB. Results A total of 315 Mycobacteria tuberculosis isolates were tested for resistance against isoniazid, rifampicin, ethambutol and streptomycin using the phenotypic proportion method on Lowenstein–Jensen media. Results showed most isolates (88.9%, 280/315) were not resistant to any anti-TB tested, 5.7% (18/315) were resistant to both isoniazid and rifampicin, 2.5% (8/315) were resistant to rifampicin only and 1.3% (4/315) were resistant to all four first-line anti-tuberculosis. Prediction of MDR TB basing on rifampicin results showed sensitivity of 100.0%, specificity of 96.3%, diagnostic accuracy of 96.5%, and positive and negative predictive values of 62.1% and 100.0%, respectively. Isoniazid had sensitivity of 100.0%, specificity of 98.3%, diagnostic accuracy of 98.4%, and positive and negative predictive values of 78.3% and 100.0%, respectively. Prediction of rifampicin resistance based on isoniazid results had sensitivity of 62.1%, specificity of 98.3%, diagnostic accuracy of 94.9%, a positive predictive value of 78.3% and a negative predictive value of 96.2%. Conclusions Resistance to either rifampicin or isoniazid sub-optimally predicts MDR-TB. Despite having high sensitivity and specificity, the positive predictive value of rifampicin was only 62.1% and for isoniazid was 78.3%, suggesting that if either is tested in isolation both could result in false positives MDR-TB cases, resulting into patients being unnecessarily subjected to the more toxic and expensive second-line anti-TB drugs, which are less effective compared to first-line anti-TB drugs.

In low-income countries, the empirical treatment of urinary tract infections (UTIs) without laboratory confirmation is very common, especially in primary health facilities. This scenario often leads to unnecessary and ineffective antibiotic prescriptions, prompting the emergence and spread of antimicrobial resistance. We conducted this study to examine the antibiogram of uropathogens causing community-acquired urinary tract infections among outpatients attending selected health facilities in Tanzania. Method: This was a cross-sectional health centre-based survey conducted for a period of five months, from July to November 2021, in the Mwanza and Dar es Salaam regions in Tanzania. We enrolled consecutively a total of 1327 patients aged between 2 and 96 years with a median [IQR] age of 28 [22–39] from Dar es Salaam (n = 649) and Mwanza (n = 678). Results: Significant bacteriuria was observed in 364 (27.4% [95%CI: 25.0–29.9]) patients, from whom 412 urinary pathogens were isolated. Gram-negative bacteria contributed to 57.8% (238) of the 412 uropathogens isolated, of which 221 were Enterobacterales, and Escherichia coli was the most frequent. Staphylococcus aureus and Staphylococcus haemolyticus were the most frequently isolated among Gram-positive uropathogens (n = 156). Generally, resistance among Escherichia coli ranged from 0.7% (meropenem) to 86.0% (ampicillin) and from 0.0% (meropenem) to 75.6% (ampicillin) in other Enterobacterales. Moreover, about 45.4% (108) of Enterobacterales and 22.4% (35) of Gram-positive bacteria were multidrug resistant (MDR), p = 0.008. We observed 33 MDR patterns among Gram-negative bacteria, predominantly AMP-CIP-TCY (23/108; 21.3%), and 10 MDR patterns among Gram-positive bacteria, most commonly CIP-GEN-TCY (22/35; 62.9%). Conclusion: the presence of a high number of wide-ranging uropathogens that are multidrug resistant to a variety of antibiotics points to the need to strengthen the laboratory diagnostic systems for the regular surveillance of the antimicrobial resistance of uropathogens to guide and update empirical treatment guidelines.

Rapid, accurate and reliable assays are required for timely detection of drug-resistant tuberculosis and early initiation of second-line TB treatment as well as to minimize transmission of resistant strains. This study assessed diagnostic performance characteristics of two rapid molecular assays, line probe assay (LPA) and GeneXpert (MTB/RIF), in the detection rifampicin monoresistance using the phenotypic proportion method on Lowenstein–Jensen media as the gold standard. This study involved a total of 357 isolates, 74 rifampicin-resistant and 283 rifampicin-susceptible, collected at the Central Tuberculosis Reference Laboratory (CTRL) in Dar es Salaam, Tanzania, between 2016 and 2019. Sensitivity, specificity and positive and negative predictive values were used to assess the performance characteristics of the two assays while kappa coefficient was used to determine agreement of test results. The receiver operating curve (ROC) was used to determine the discriminatory ability of the test in distinguishing resistant and susceptible TB isolates. Our results showed that GeneXpert had sensitivity, specificity and positive and negative predictive values of 93.2, 82.7, 58.5 and 97.9%, respectively; the corresponding performance for LPA was 86.5, 97.5, 90.1 and 96.5%, respectively. Compared with conventional phenotypic DST results, GeneXpert had a moderate agreement (kappa 0.621, p < 0.001), while LPA had high agreement (0.853, p < 0.001). LPA showed an accuracy of 95.2% compared to GeneXpert’s 84.9%. ROC curve depicted the ability of the tests to distinguish rifampicin-sensitive and rifampicin-resistant strains to be 87.9% for GeneXpert and 92.0% for LPA. Our results indicate the superiority of LPA over GeneXpert regarding detection of rifampicin monoresistance. However, logistic challenges such as longer turnaround time and need for skilled laboratory personnel may limit its use.

In Tanzania, the increased demand for animal-derived foods, particularly eggs, meat, and milk, has resulted in the intensification of farming systems with the use of antimicrobials, particularly sulphonamides and tetracyclines. According to the FAO/WHO Codex Alimentarius commission, concentrations of antimicrobial residues in food exceeding the acceptable daily intake (ADI) and maximum residual limit (MRL) pose a health risk to consumers. This cross-sectional study determined the concentrations of sulphonamide and tetracycline residues in the liver tissues of commercial broiler chicken sold in Dar es Salaam, Tanzania, to find out whether the amounts of residues were within the legally permitted and acceptable limits in food. We conveniently sampled eighty-four liver tissue samples from broiler chicken sold in two out of six large markets in Dar es Salaam. The amounts of tetracycline and sulphonamide residues were determined using an ELISA kit (Shenzhen Lvshiyuan Biotechnology Company, Shenzhen, China). The results showed that all 100% (n = 84) samples contained tetracycline residues and 21.4% (n = 18) samples contained sulphonamide residues, while 21.4% (n = 18) contained both sulphonamide and tetracycline residues. The concentrations of sulphonamide residues were within the maximum residual limit (MRL). However, 90.5% (n = 76) of the samples had tetracycline levels that exceeded the acceptable daily intake (ADI) range 0–3 µg/kg and 13.1% (n = 11) of the samples had tetracycline levels that exceeded the maximum residue limit of 300 µg/kg. The observed presence of antibiotic residues in the poultry tissues poses a health risk to consumers, and may lead to antimicrobial resistance micro-organisms, which may spread to humans and animals via the environment. Vigorous surveillance and observation of the withdrawal periods should be advocated to ensure that the food from animals is safe with regard to the residues of veterinary medicines.

We determined the phenotypic profile of multidrug-resistant (MDR) Escherichia coli isolated from 698 samples (390 and 308 from poultry and domestic pigs, respectively). In total, 562 Enterobacteria were isolated. About 80.5% of the isolates were E. coli. Occurrence of E. coli was significantly higher among domestic pigs (73.1%) than in poultry (60.5%) (p = 0.000). In both poultry and domestic pigs, E. coli isolates were highly resistant to tetracycline (63.5%), nalidixic acid (53.7%), ampicillin (52.3%), and trimethoprim/sulfamethoxazole (50.9%). About 51.6%, 65.3%, and 53.7% of E. coli were MDR, extended-spectrum beta lactamase-producing enterobacteriaceae (ESBL-PE), and quinolone-resistant, respectively. A total of 68% of the extended-spectrum beta lactamase (ESBL) producers were also resistant to quinolones. For all tested antibiotics, resistance was significantly higher in ESBL-producing and quinolone-resistant isolates than the non-ESBL producers and non-quinolone-resistant E. coli. Eight isolates were resistant to eight classes of antimicrobials. We compared phenotypic with genotypic results of 20 MDR E. coli isolates, ESBL producers, and quinolone-resistant strains and found 80% harbored blaCTX-M, 15% aac(6)-lb-cr, 10% qnrB, and 5% qepA. None harbored TEM, SHV, qnrA, qnrS, qnrC, or qnrD. The observed pattern and level of resistance render this portfolio of antibiotics ineffective for their intended use.

This cross-sectional study was conducted between January and June 2020, in five large poultry slaughter slabs in Dar es Salaam, Tanzania. Purposive sampling was used to select broilers and spent layers, from which meat and cloaca swabs were collected to determine the occurrence of multidrug resistant (MDR) Escherichia coli. Identification of isolates was done using API 20E, and antimicrobial susceptibility testing was performed as per CLSI (2018) guidelines. EBSL (CTX-M, TEM, SHV) and plasmid mediated quinolone (qnrA, qnrB, qnrS and aac(6′)-Ib-cr) were screened using PCR. Out of 384 samples, 212 (55.2%) were positive for E. coli, of which 147 (69.3%) were resistant to multiple drugs (MDR). Highest resistance was detected to tetracycline (91.9%), followed by sulfamethoxazole-trimethoprim (80.5%), ampicillin (70.9%), ciprofloxacin (40.2%) and 25% cefotaxime, gentamycin (10.8%) and imipenem (8.6%) (95% CI, p < 0.01). Out of the E. coli-positive samples, ten (10/212) (4.7%) were ESBL producing E. coli, of which CTX-M was detected in two isolates and quinolones resistant gene (qnrS) in eight, while TEM, SHV, qnrA, qnrB and aac(6′)-lb-cr were not detected. The high level of resistance and multidrug resistance imply these antibiotics are ineffective, add unnecessary cost to poultry farmers and certainly facilitate emergence and spread of resistance.