Department of Microbiology, University of Medical Sciences, Ondo, Nigeria.
Department of Microbiology, Dennis Osadebay University Anwai, Asaba, Delta State, Nigeria.
Sci Rep. 2023 Aug 4;13(1):12646. doi: 10.1038/s41598-023-39955-0.
Listeria outbreaks and food recalls is on the raise globally. Milk particularly is highly susceptible to Listeria as its production and storage adequately support Listeria growth. The extent of milk contamination with Listeria monocytogenes (Lm) and preventative actions to halt milk associated outbreaks in Africa are unknown. Hence, this study aimed at assessing the national and subregional prevalence of Lm in milk in Africa and identify impacting factors via generalized logistic mixed-effects (GLMEs) and meta-regression modelling. Lm-milk-specific data acquired from primary studies according to standard protocol were fitted using a GLMEs. The GLMEs was subjected to leave-one-study-out-cross-validation (LOSOCV). Factors impacting Lm prevalence in milk were assayed via a 1000-permutation-assisted meta-regression-modelling. The pooled prevalence of Lm in milk in Africa was 4.35% [2.73-6.86] with a prediction interval (PI) of 0.14-59.86% and LOSOCV value of 2.43% [1.62-3.62; PI: 0.32-16.11%]. Western Africa had the highest prevalence [20.13%, 4.13-59.59], then Southern Africa [5.85%, 0.12-75.72], Northern Africa [4.67%, 2.82-7.64], Eastern Africa [1.91%, 0.64-5.55], and there was no record from Central Africa. In term of country, Lm prevalence in milk significantly (p < 0.01) varied from 0.00 to 90.00%. Whereas the Lm prevalence was negligibly different (p = 0.77) by milk type, raw-milk had the highest prevalence [5.26%], followed by fermented-milk [4.76%], boiled-milk [2.90%], pasteurized-milk [1.64%], and powdered-milk [1.58%]. DNA extraction approach did not significantly (p = 0.07) affect Lm prevalence (Boiling [7.82%] versus Kit [7.24%]) as well as Lm detection method (p = 0.10; (ACP [3.64%] vs. CP [8.92%] vs. CS [2.27%] vs. CSP [6.82%]). Though a bivariate/multivariate combination of all tested variables in meta-regression explained 19.68-68.75% (R) variance in Lm prevalence in milk, N, nation, and subregion singly/robustly accounted for 17.61% (F = 7.5994; p = 0.005), 63.89% (F = 4.2028; p = 0.001), and 16.54% (F = 3.4743; p = 0.026), respectively. In conclusion, it is recommended that adequate sample size should be prioritized in monitoring Lm in milk to prevent spuriously high or low prevalence to ensure robust, plausible, and credible estimate. Also, national efforts/interests and commitments to Lm monitoring should be awaken.
李斯特菌爆发和食品召回在全球范围内呈上升趋势。牛奶尤其容易受到李斯特菌的污染，因为其生产和储存方式非常有利于李斯特菌的生长。目前尚不清楚非洲牛奶中单核细胞增生李斯特菌（Lm）的污染程度以及预防与牛奶相关的疫情爆发的措施。因此，本研究旨在评估非洲牛奶中 Lm 的国家和次区域流行率，并通过广义逻辑混合效应（GLME）和荟萃回归模型确定影响因素。根据标准协议从原始研究中获取的 Lm-牛奶特异性数据使用 GLME 进行拟合。GLME 进行了一次留一研究外交叉验证（LOSOCV）。通过 1000 次置换辅助荟萃回归模型分析了影响 Lm 流行率的因素。非洲牛奶中 Lm 的总流行率为 4.35%[2.73-6.86]，预测区间（PI）为 0.14-59.86%，LOSOCV 值为 2.43%[1.62-3.62;PI：0.32-16.11%]。西非的流行率最高[20.13%，4.13-59.59%]，其次是南非[5.85%，0.12-75.72%]，北非[4.67%，2.82-7.64%]，东非[1.91%，0.64-5.55%]，中非没有记录。就国家而言，牛奶中 Lm 的流行率存在显著差异（p<0.01），范围从 0.00%到 90.00%。尽管牛奶类型对 Lm 的流行率（原始奶[5.26%]、发酵奶[4.76%]、煮奶[2.90%]、巴氏奶[1.64%]和奶粉[1.58%]）没有明显影响（p=0.77），但 DNA 提取方法的影响并不显著（p=0.07）。（煮沸[7.82%]与试剂盒[7.24%]），以及 Lm 检测方法（p=0.10；（ACP[3.64%]与 CP[8.92%]、CS[2.27%]与 CSP[6.82%]）。尽管荟萃回归中的所有测试变量的双变量/多变量组合解释了牛奶中 Lm 流行率的 19.68-68.75%（R）方差，但 N、国家和次区域单独/稳健地解释了 17.61%（F=7.5994；p=0.005）、63.89%（F=4.2028；p=0.001）和 16.54%（F=3.4743；p=0.026）。总之，建议在监测牛奶中的 Lm 时应优先考虑足够的样本量，以防止出现过高或过低的流行率，从而确保可靠、合理和可信的估计。此外，还应唤醒国家对 Lm 监测的重视和投入。
